Program and Abstracts
8-11 December, 2015 The University of Sydney Sydney, AUSTRALIA
SPONSORS
WELCOME TO OZOM IX
Welcome to OZOM IX, the 9th Australasian Organometallics meeting of the Royal Australian Chemical Institute, focussing on the cross-divisional discipline of organometallic chemistry. The program again caters for all applications of the field.
In keeping with the common theme of all the previous highly successful meetings in this series, the program also maintains its strong student and early career researcher focus through both contributed oral and poster presentations. In addition, a number of eminent researchers from Germany will be delivering plenary lectures at the meeting amongst a further list of international delegates attending the meeting.
The organising committees would like to extend a warm welcome to all delegates.
Enjoy your time in Sydney!
Local Organising Committee
Lou Rendina (Chair) Rob Baker (Treasurer) Peter Lay Tony Masters Peter Rutledge Ant Ward
National Organising Committee
Phil Andrews, Marie Cifuentes, Michael Gardiner, Mark Humphrey, Peter Junk, and George Koutsantonis
DETAILED PROGRAM
TUESDAY 8 DECEMBER
17.30 - 18.30 Registration (The Grandstand)
18.30 - 20.30 Opening Mixer (The Grandstand)
WEDNESDAY 9 DECEMBER
8.50 - 9.00 Welcome (Lou Rendina, Chair) 9.00 - 10.00 Plenary Lecture 1 (PL1): Prof. F. E. Hahn LECTURE SESSION Synthesis and Reactivity of Complexes Bearing Protic NHC Session Chair: Ligands George Koutsantonis 10.00 - 10.20 Oral Lecture 1 (OL1): N. Camasso Design, Synthesis, and Reactivity of Organometallic Ni(IV) Complexes
10.20 - 10.40 Oral Lecture 2 (OL2): S. Scottwell The Synthesis and Switching of a Molecular Folding Ruler
10.40 - 11.10 morning tea
LECTURE SESSION 11.10 - 11.30 Oral Lecture 3 (OL3): S. Ali Syntheses and Reactivity of New Heteroleptic Formamidinate Session Chair: Rare Earth Metal Complexes from Pseudo-Grignard Reaction Chris Hyland 11.30 - 11.50 Oral Lecture 4 (OL4): T. Field-Theodore A Theoretical Exploration into Highly Stabilized, Non-Lewis acidic, Anti-Aromatic Beryllium Ring Systems
11.50 - 12.10 Oral Lecture 5 (OL5): L. Abad Galán Lanthanoid β-triketonate Assemblies With Improved Near- Infrared Emission
12.10 - 12.30 Oral Lecture 6 (OL6): D. Twycross Developing the Chemistry of N-2,6-terphenyl Substituted N- Heterocyclic Carbenes
12.40 - 13.50 lunch
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WEDNESDAY 9 DECEMBER (continued)
13.50 - 14.50 Plenary Lecture 2 (PL2): Dr A. Stasch LECTURE SESSION RACI Organometallic Chemistry Award Session Chair: s-Block Metal Hydride Complexes: Syntheses, Properties and Anthony Hill Applications
14.50 - 15.20 afternoon tea
LECTURE SESSION 15.20 - 15.40 Oral Lecture 7 (OL7): A. Triadon Third-order Nonlinear Optical Properties of Group 8 Metal Session Chair: Victoria Blair Alkynyl Complexes Containing Fluorenyl Moieties 15.40 - 16.00 Oral Lecture 8 (OL8): J.-S. Huang Azavinylidene Complexes of Metalloporphyrins and Metallophthalocyanines
16.00 - 16.20 Oral Lecture 9 (OL9): P. Jurd Coupling Reactivity of Carbon Dioxide and Acetylene Mediated by Iron Phosphine Complexes
16.20 - 16.40 Oral Lecture 10 (OL10): A. Davey Formation of Bulky Amido Stabilised Dipnictenes via Highly Reactive Pnictinidene Intermediates
16.40 - 17.00 Oral Lecture 11 (OL11): E. Clatworthy
Electrochemical Investigation of [Co4(µ3-O4)(µ-OAc)4(py)4] and Peroxides by Cyclic Voltammetry
POSTER SESSION 17.00 - 18.30 Poster Session (P1-P23)
P1: Z. Guo Novel and simple method to synthesize silver pyrazolates
P2: S. Harris Hybrid Stacked/Laddered Organolithium Aggregates: A Structural Hypothesis for Superbase Activity
P3: R. Ojha EPR spectroscopic characterisation and fate of a monomeric PtIII species produced via electrochemical oxidation of the anticancer compound trans-[PtII{(p-
BrC6F4)NCH2CH2NEt2}Cl(py)]
WEDNESDAY 9 DECEMBER (continued)
POSTER SESSION P4: R. Deka (continued) Synthesis of pyrrole based N-heterocyclic chalcogenides and 8,8´-diquinoline dichalogenides
P5: N. Eslamirad The Synthesis and structure of the Rare-Earth 3, 5- Dimethylpyrazolate complexes
P6: M. Flynn Anion Rearrangements in Alkali Metal Complexes of (S)-N-(α- Methylbenzyl)methallylamide
P7: J. Greer Novel Structures of Naphthyl Lithium Amides
P8: C. Quintana Bioorganometallic Complexes as Anti-Cancer and Anti- Tuberculosis Agents: Synthesis, Characterization and Biological Evaluation
P9: C. Vanston “Normalised” abnormal carbene palladium complexes
P10: K. Burke Synthesis and characterisation of novel di- and tri-bismuth(III) aromatic compounds and evaluation of their anti-Leishmanial activity
P11: R. Manzano Selenium-interrupted carbochain bridged bimetallics
P12: C. de Bruin-Dickason Divalent Lanthanoid Complexes of Bulky Amide Ligands
P13: F. Zamani Diastereoselective and Regioselective Allenylation of Chiral Amino Aldehydes
P14: N. Lucas
Ancillary Ligand Effects in Donor-Acceptor Re(CO)3(dppz) Complexes
P15: M. Mudge A Dixanthene Scaffold for Cooperative Catalysis
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WEDNESDAY 9 DECEMBER (continued)
P16: L. Ezzedinloo POSTER SESSION Organo-transition metal complexes for electrocatalyic (continued) reduction of carbon dioxide
P17: J. McPherson Dipyridylpyrrolato anion analogues of terpyridine metal complexes
P18: A. Boutland Monodentate Ligands For The Stabilisation Of Two Coordinate Magnesium(I) Dimers
P19: A. McDonagh Remarkable Thermal Stability of Gold Nanoparticles Utilising Organic and Inorganic Stabilisers
P20: C. Barnett Understanding N-Heterocyclic Carbene Properties
P21: K. Buys Using Pincer Ligands to Study s- and p-Block Halides and Hydrides
P22: A. Nolan Effects of donor/acceptor geometry in organo-ruthenium cruciforms for NLO studies
P23: I. Pernik The Use of Electronically and Sterically Modified β- Diketiminates (NacNac-s) for Stabilising Low Oxidation Magnesium and Group 13 and 14 Complexes
THURSDAY 10 DECEMBER
9.00 - 10.00 Plenary Lecture 3 (PL3): Prof. J. Weigand LECTURE SESSION Application of Cationic Phosphanes Session Chair: Peter Junk 10.00 - 10.20 Oral Lecture 12 (OL12): S. Binding Building Blocks for Organometallic Polymers: Spin-Equilibrium Behavior in Some First Row Transition Metal Anti-Bimetallic Complexes
10.20 - 10.40 Oral Lecture 13 (OL13): T. Nicholls Design and Synthesis of a Novel Abnormal N–Heterocyclic Carbene Complex
10.40 - 11.10 morning tea
LECTURE SESSION 11.10 - 11.30 Oral Lecture 14 (OL14): T. Hadlington Modern Main-Group Chemistry: From Curiosity to Catalysis Session Chair: Michael Gardiner 11.30 - 11.50 Oral Lecture 15 (OL15): P. Simpson Photophysical, Photochemical, and Biological Studies of Tricarbonyl Rhenium(I) N-Heterocyclic Carbene Complexes
11.50 - 12.10 Oral Lecture 16 (OL16): M. Roemer Ruthenium Complexes of Versatile 4,5-Diazafluoren-9-yl Ligands with Two Coordination Sites
12.10 - 12.30 Oral Lecture 17 (OL17): A. Nair Ru, Ni and Au Complexes of Hemilabile Pincer Ligands for Enhanced Catalysis
12.30 - 13.50 lunch
LECTURE SESSION 13.50 - 14.10 Oral Lecture 18 (OL18): Ke. Gloe Uranyl(VI) Binding and Extraction by Bis(2-hydroxyaryl)diimine and Session Chair: Bis(2-hydroxyaryl)-diamine Ligand Derivatives Mark Humphrey 14.10 - 14.30 Oral Lecture 19 (OL19): C. Ma Complexes of PSiP and N-Heterocyclic Carbene Pincer Ligands 14.30 - 14.50 Oral Lecture 20 (OL20): Y. Ong Stability of tris-aryl Bi(V) dicarboxylates & their biological activity towards Leishmania major
14.50 - 15.20 afternoon tea
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THURSDAY 10 DECEMBER (continued)
LECTURE SESSION 15.20 - 15.40 Oral Lecture 21 (OL21): Ka. Gloe Session Chair: 4-Acylpyrazolones: An Old Ligand Family with a New Cameron Jones Coordination Mode
15.40 - 16.00 Oral Lecture 22 (OL22): M. Kodikara Computational Study of Bridge Variation of Metal Alkynyl Complexes
16.00 - 16.20 Oral Lecture 23 (OL23): C. Wong Recyclable Hybrid Rh and Ir Catalysts for C-X Bond Formation Reactions
16.20 - 16.40 Oral Lecture 24 (OL24): M. Morshedi Dipolar Hybrid Schiff Base-Metal Alkynyl Complexes for Nonlinear Optics
16.40 - 17.00 Oral Lecture 25 (OL25): J. Markham Investigating the Anti-Cancer Potential of Rh- Pentamethylcyclopentadiene Complexes
POSTER SESSION 17.00 - 18.30 Poster Session (P24-P45)
P24: R. Vasdev 6+ Synthesis of a family of [M2L3] helicates and mesocates derived from bis(bidentate) 2-pyridyl-1,2,3-triazole “click” ligands: Towards antimicrobial helicates
P25: M. Morshedi Ruthenium Alkynyl Cruciform and Solubility Corundum
P26: V. Diachenko The Kinetic Stabilisation of Main Group and Transition Metal Complexes with a Super Bulky Diiminopyridine
P27: K. S. A. Arachchige Weak Te-Te Interactions in Naphthalene and related scaffolds
THURSDAY 10 DECEMBER (continued)
P28: M. Younus POSTER SESSION (continued) Synthesis of Novel Platinum Poly-ynes with Pendant Liquid Crystalline Cores
P29: A. Aldabbagh Synthesis, characterisation and biological applications of haloformamidinatoantimony(III) complexes
P30: M. Salehisaki Synthesis of rare earth complexes involving N,N'- di(diphenyl)formamidine ligand
P31: M. Gatus Homo- and Heterobimetallic Complexes Used as Catalysts for a Range of Organic Transformations: Lessons Learned
P32: J. Atkinson-Bodourian Synthesis of the First Reported Cyclic (alkyl)(amino)Carbene (CAAC)-Group 13 Metal (M= Al, Ga, or In) Complexes
P33: C. Caporale Photophysical trends in iridium(III) tetrazolate complexes
P34: S. Furfari Group 8 and 9 Complexes Bearing an Anionic Carbon Centred Podand Ligand
P35: P. M. Abeysinghe Protonation of Dinitrogen to Ammonia on Ruthenium and Iron Complexes Containing Tripodal Phosphine Ligands
P36: R. Corbo Homoleptic Au(III) trications: A synthetic pathway to a novel class of Au(III) compounds
P37: R. Baker Configuration-Dependent Kinetic Indenyl Effects in Metal- Centered Epimers of n5:k2(C,S)-Indenyl-Phenethylsulfanyl Rhodacycles
P38: A. Hall Tumour Selective Gadolinium Agents as Binary Cancer Therapies
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THURSDAY 10 DECEMBER (continued)
POSTER SESSION P39: S. Streatfield (continued) New Platinum Octupolar Complexes for Nonlinear Optics
P40: J. Kelly Utilising Bulky Monodentate Alkyl/Aryl Substituted Amido- Ligands to Stabilise Low Oxidation State Silicon Compounds
P41: K. von Nessi
CAC vs. ACC (A= S, Se, Te, BOMe, SnMe2, PR; R = Cl, Ph, Cy) bridged bimetallics
P42: M. Dawkins Reduced Group 2 diiminopyridine complexes: synthesis, structure and 2-electron reactivity
P43: N. Akabar Photophysical and photochemical investigation of tricarbonyl rhenium(I) diimine and N-heterocyclic carbene complexes
P44: Y. Xiang The divergent application of three-membered strained-ring systems in the palladium- catalysed ring-opening reaction
P45: L. Quan Ir(III)-1,2,4 triazole donor and Lanthanide acceptor for electrochemically sensitized luminescence
19.00 - late OZOM IX dinner (Thai Pothong)
FRIDAY 11 DECEMBER
9.00 - 9.20 Oral Lecture 26 (OL26): M. Hossain LECTURE SESSION Synthesis of Lanthanoid-Aluminium Bimetallic Complexes Session Chair: Max Massi 9.20 - 9.40 Oral Lecture 27 (OL27): E. Border Metallations of Imines: Addition, Deprotonation and Cyclisation
9.40 - 10.00 Oral Lecture 28 (OL28): T. Wierenga Mechanistic Studies of Catalytically Relevant N-Heterocyclic Carbene Transformations 10.00 - 10.20 Oral Lecture 29 (OL29): Y.-S. Han An Exploration of Primary Phosphine and Phosphido Chemistry
10.20 - 10.40 Oral Lecture 30 (OL30): C. Hyland Transition-Metal Mediated Reactions of Strained Ring Systems 10.40 - 11.10 morning tea
LECTURE SESSION 11.10 - 12.10 Plenary Lecture 4 (PL4): Prof. R. Kempe Catalysts for a More Sustainable Chemistry Session Chair: Phil Andrews
12.10 - 12.30 Student Poster and Oral Prize Awards and Conference Close
13.00 - 14.00 closing drinks
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ABSTRACTS
GRAPHICAL
PL1 Synthesis and Reactivity of Complexes Bearing Protic NHC Ligands
F. Ekkehardt Hahn
The preparation, properties and reactivity of complexes bearing protic NHC ligands such as 1−5 will be presented and discussed.
PL2 s-Block Metal Hydride Complexes: Syntheses, Properties and Applications
A. Stasch
The chemistry of well-defined, ligand-stabilized s-block metal hydride complexes is described.
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PL3 Application of cationic phosphanes
J. J. Weigand
In this contribution we report on the synthesis and application of novel imidazoliumyl substituted phosphorous based cations bearing highly electronegative groups, such as cationic imidazoliumyl substituents.
PL4 Catalysts for a more sustainable chemistry
R. Kempe
In the talk, the development of (i) the acceptorless dehydrogenative condensations (ADC) concept, (ii) novel ADC reactions, (iii) robustly supported reusable catalysts for ADC, (iv) base metal catalysts, and (v) novel catalytic concepts possible due to progress made in ADC recently, are discussed. åå
OL1 of these complexes toward important bond forming Design, Synthesis, and Reactivity of reactions are discussed. Organometallic Ni(IV) Complexes
Nicole M. Camasso, James R. Bour, Allan J. H N B N Ph2IBF4 Canty, Melanie S. Sanford N or CF3 N CF PhN2BF4 Δ NiII 3 N N This presentation describes the synthesis of CF3 organometallic Ni(IV) complexes accessed by the 2e– oxidation of Ni(II) precursors with trifluoromethyl and aryl oxidants. The reactivity Isolable Ni(IV) Complex
OL2
The Synthesis and Switching of a Molecular Folding Ruler
Synøve Ø. Scottwell, James D. Crowley
A larger molecular folding ruler has been developed following the successful synthesis and switching of a ferrocene-based molecular actuator.
OL3 Syntheses and Reactivity of New Heteroleptic Formamidinate Rare Earth Metal Complexes from Pseudo-Grignard Reaction Safaa Ali, Peter Junk, Jun Wang
Pseudo-Grignard reagents [1, 2], ‘‘RLnX’’ (Ln =
Eu and Yb; R = Me, Ph or C6H2Me3-2, 4, 6; X = Br, I), formed by the treatment of organic halides like PhBr or PhI with rare earth metals in Lewis base solvents.
OL4 A theoretical exploration into highly stabilized, non-Lewis acidic, anti-aromatic beryllium ring systems Terri E. Field-Theodore, David J. D. Wilson, and Jason L. Dutton
Our study explores “Beryloles”, synthetically unknown anionic analogues of anti-aromatic boroles. Calculations indicate that these new beryllium based systems are electronically viable and thus, potential targets for synthetic chemists.
OL5
Lanthanoid β-triketonate assemblies with improved near-infrared emission
Laura Abad Galán, Brodie L. Reid, Mark I. Ogden, Eli Zysman-Colman, Max Massi
New lanthanoid complexes with β-triketonate ligands present remarkable near-infrared emission.
OL6 Developing the Chemistry of N-2,6-terphenyl Substituted N-Heterocyclic Carbenes
Daniel Twycross, Marcus L. Cole
The stereoelectronic properties of two flexible steric bulk NHCs has been investigated. Herein we report their use as supports for palladium cross coupling and group 13 hydrides.
OL7 Third-order nonlinear optical properties of Group 8 metal alkynyl complexes containing fluorenyl moieties
A. Triadon,1,2 F. Malvolti,1 G. Grelaud,1,2 G. J. Moxey,2 A. Barlow,2 F. Paul,1 O. Mongin,1 M. P. Cifuentes,2 M. G. Humphrey2
A series of iron and ruthenium metal alkynyl complexes were synthesized and their linear and nonlinear optical properties were investigated.
OL8 Azavinylidene Complexes of Metalloporphyrins and Metallophthalocyanines
Jie-Sheng Huang,* Kwok-Ming Wong, Wai-Man Tsui, Ken Chi-Hang Tso, Chi-Ming Che*
This presentation describes the recent chemistry of high-valent metal azavinylidene complexes, including trans-bis(azavinylidene) complexes, supported by cyclic chelating ligands.
OL9 Coupling Reactivity of Carbon Dioxide and Acetylene Mediated by Iron Phosphine Complexes
Peter M. Jurd, Leslie D. Field, Mohan M. Bhadbhade, Scott J. Dalgarno
Reaction of iron phosphine complexes bearing activated acetylene with carbon dioxide is found to result in differing reaction outcomes based upon CO2 substrate pressure.
OL10 LEX2 + Reducing agent Formation of bulky amido stabilised dipnictenes via highly reactive pnictinidene intermediates L-E
Amelia Davey, Cameron Jones
Dimerised product Reduction of amido group 15 element dihalide C-H activated product precursors to produc a range of products; C-H E= P E= As, Sb, Bi activated, [2+1]-cycloaddition, and element(I) [2+1]-cycloaddition product products E= P, As
OL11 Electrochemical investigation of [Co4(µ3-O4)(µ-OAc)4(py)4] and peroxides by cyclic voltammetry
Edwin B. Clatworthy, Xiaobo Li, Anthony F. Masters, Thomas Maschmeyer
A second quasi-reversible oxidation process was discovered for a cobalt-cubane complex. Its behaviour in the presence of water and peroxide species was investigated by cyclic voltammetry.
OL12 Building blocks for organometallic polymers: spin-equilibrium behavior in some first row transition metal anti-bimetallic complexes
Samantha C. Binding, Jennifer C. Green, Dermot O’Hare
Bimetallic Pn* complexes of first row transition metals have been studied by VTNMR, SCXRD and DFT.
OL13 Design and Synthesis of a Novel Abnormal N– Heterocyclic Carbene Complex
H3C N Thomas P. Nicholls, C. R. Vanston, C. C. Ho, A. S C. Bissember, M. G. Gardiner H3C I N This presentation discusses key aspects of the Pd N N synthesis and physical and spectroscopic H3C I properties of an unprecedented abnormal N– CH3 . heterocyclic carbene (1) and related complexes. 1
OL14 Modern Main-Group Chemistry: From Curiosity to Catalysis
T. J. Hadlington, C. Jones
The development of super-bulky monodentate amide ligands has led to the first examples of group 14 element(II) catalysed transformations, and to the isolation of the first bis(amido) acyclic silylene.
OL15 Photophysical, Photochemical, and Biological Studies of Tricarbonyl Rhenium(I) N- Heterocyclic Carbene Complexes
Peter Simpson, Brian Skelton, Paolo Raiteri, Annika Groß, Ingo Ott, Massimilliano Massi
Rhenium NHC complexes bound to azide anions readily react with alkynes to form the corresponding triazolate complexes, a new class of photochemically active species.
OL16 Ruthenium Complexes of Versatile 4,5- Diazafluoren-9-yl Ligands with Two Coordination OH Sites N N N Ph2P PPh2 N
Max Roemer, Lesley Yie Ai Yong, Philip A. Schauer, N Ru N Cl Ru C C Campbell F. R. McKenzie, Laetia Le Gal, Siobhan N Ph2P PPh2 Wills, Brian W. Skelton, George A. Koutsantonis N N N
Two complexation strategies and combination of both: on the way to bicentered Ru-complexes.
OL17 Ru, Ni and Au Complexes of Hemilabile Pincer Ligands for Enhanced Catalysis
Ashwin Gopalan Nair, Mark R. D. Gatus, and Barbara A. Messerle
Incorporation of NHCs into a tridentate pincer geometry can lead to complexes that exhibit hemilability. This hemilabile characteristic can enhance the catalytic activity of the transition metal complexes.
OL1 8 Uranyl(VI) Binding and Extraction by Bis(2- hydroxyaryl)diimine and Bis(2-hydroxyaryl)- diamine Ligand Derivatives
Kerstin Gloe, Karsten Gloe, Leonard F. Lindoy, Jan J. Weigand
The interaction of uranyl(VI) nitrate with a series of bis(2-hydroxyaryl)imine and bis(2-hydroxy- aryl)amine derivatives incorporating different bridges between nitrogen sites is reported.
OL19 Complexes of PSiP and N-Heterocyclic Carbene Pincer Ligands
Chenxi Ma, Anthony F. Hill, Lily S. Dixon, Jas S. Ward
C–H and Si–H activation processes involving dihydroperimidene and siladiazole pincer pro- ligands affords convenient access to d8 square- planar complexes of iridium(I) and rhodium(I).
OL20 Stability of tris-aryl Bi(V) dicarboxylates & their biological activity towards Leishmania major
Yih Ching Ong, Victoria L. Blair, Lukasz Kedzierski, Kellie L. Tuck, Philip C. Andrews*
A series of tris-aryl Bi(V) dicarboxylates were characterised and evaluated against L. major promastigotes and amastigotes.
OL21 4-Acylpyrazolones: An old ligand family with a new coordination mode
Karsten Gloe, Kerstin Gloe, Melanie Mohn, Jan J. Weigand
The synthesis and structures of d- and f- block metal complexes with 4-propionyl-3-methyl-1- phenyl-5-pyrazolone is reported.
OL22 Computational study of bridge variation of metal alkynyl complexes
M.S. Kodikara, R. Stranger, M.G. Humphrey
DFT/TD-DFT calculations were used to rationalise the experimental linear and nonlinear optical data of a set of ruthenium alkynyl complexes with phenyl, naphthalenyl, and anthracenyl bridges.
OL23 Recyclable Hybrid Rh and Ir Catalysts for C-X Bond Formation Reactions Chin Min Wong, D. Barney Walker, Alex H. Soeriyadi, J. Justin Gooding, Barbara A. Messerle
A direct and applicable route for developing Rh and Ir hybrid catalysts on carbon surfaces is presented. The catalysts were efficient and recyclable for C-X bond forming reactions.
OL24 Dipolar Hybrid Schiff Base-Metal Alkynyl Complexes for Nonlinear Optics
Mahbod Morshedi, Marie P. Cifuentes, Mark G. Humphrey
The marriage between the intrinsic electronic properties of Schiff base complexes and alkynylruthenium complexes gives rise to highly polarizable dipolar hybrids.
OL25 Investigating the Anti-Cancer Potential of Rh- Pentamethylcyclopentadiene Complexes
J. Markham, J. Liang, A. Levina, P. A. Lay
Rh-*Cp complexes are evaluated in terms of their potential use as anti-cancer drugs using a series of in vitro methods, as well as X-ray absorption spectroscopy.
OL26
Synthesis of Lanthanoid-Aluminium H3C Bimetallic Complexes I I I# Yb Md Elius Hossain, Jun Wang and Peter Junk Al I A serial of new complexes have been synthesized I I through the reactions between aluminum iodide Al I and lanthanoid iodides in toluene at 110°C for two hours. I I
OL27 Metallations of Imines: Addition, Deprotonation and Cyclisation
E. Border, P. Andrews
When N-[(4-methoxyphenyl)methylene]- benzenamine is reacted with nBuNa it undergoes an unprecedented 1,2 addition. The same imine when reacted with NaHMDS or LDA undergoes a deprotonation or cyclisation respectively.
OL28
Mechanistic Studies of Catalytically Relevant N-Heterocyclic Carbene Transformations Tanita Wierenga, Michael Gardiner, Curtis Ho, Alireza Ariafard
Unusual on-metal N-Heterocyclic carbene rearrangements have been seen during extended linker Pd(bisNHC) complex synthesis. Synthetic and DFT mechanistic studies of this mechanism will be presented.
OL29 Tp Tp An Exploration of Primary Phosphine and PH2Cy Ru Ru Phosphido Chemistry Ph3P Cl MeOH Ph3P PH2Cy Ph3P CyH2P
Yong-Shen Han, Anthony F. Hill PH2Cy C7H8
A selection of trispyrazolylborate-supported Tp primary phosphine complexes have been Ru synthesised. With the goal of investigating novel Ph3P Cl phosphido complexes, their deprotonation and CyH2P subsequent reactivity has also been studied.
OL30 Transition-metal mediated reactions of strained ring sytems
X Christopher Hyland, JieXiang Yin, Yi Sing Gee versatile substrates for and Daniel Rivinoja R metal-catalysed reactions X= C(CO2Et)2 or A range of transition-metal catalysed ring- X= NTs opening reactions of activated three-membered rings will be presented. A focus will be on reactions between these systems and indoles.
P1 Novel and simple method to synthesize silver pyrazolates
Zhifang Guo, Glen B. Deacon*, Andreas Stasch, py or CH CN 3 Peter C. Junk 3Ag2O + 6R2pzH [Ag3(R2pz)3]2 + 3H2O stir 20 min t Silver pyrazolates [Ag3(Ph2pz)3]2, [Ag( Bu2pz)]4, and [Ag(Phtpz)3] were successfully synthesized by stirring silver oxide and R2pzH, Ph2pzH, t Bu2pzH, and PhtpzH respectively, either in py or CH3CN with high yields.
P2 Hybrid Stacked/Laddered Organolithium Aggregates: A Structural Hypothesis for Superbase Activity
S. R. Harris, M. G. Gardiner, N. L. Kilah
Investigating structural changes for mixed anion organolithium complexes and understanding the effect of these changes on any superbasic activity exhibited
P3 EPR spectroscopic characterisation and fate of a monomeric PtIII species produced via electrochemical oxidation of the anticancer compound trans-[PtII{(p- BrC6F4)NCH2CH2NEt2}Cl(py)]
Ruchika Ojha, Alan M. Bond, Glen B. Deacon, Stephen P. Best, Peter C. Junk Electrochemical and chemical oxidation of the anticancer compound trans-[PtII{(p- BrC6F4)NCH2CH2NEt2}Cl(py)] is described and Monomeric PtIII species generated via electrochemical oxidation is identified by EPR spectroscopy.
P4 Synthesis of pyrrole based N-heterocyclic chalcogenides and 8,8´-diquinoline dichalogenides
Rajesh Deka, Harkesh B. Singh,* Glen B. Deacon,*, David Turner * and Peter C. Junk*
The reaction of Li[NC4H2(CH2NMe2)2-2,5] with PhEBr (E = Se, Te) leads to the formation of pyrrole-chalcogen complexes. 8,8´-diquinoline dichalcogenide were synthesized by the reaction of 8-bromoquinoline with Na2E2.
P5 The Synthesis and structure of the Rare-Earth 3, 5-Dimethylpyrazolate complexes
N. Eslamirad, P. C. Junk, J. Wang
Two different crystal structures with the same reaction were synthesized through the redox transmetalation/ protolysis with the scandium, Hg (C6F5)2, and Me2pzH.
P6 Anion Rearrangements in Alkali Metal Complexes of (S)-N-(α- Methylbenzyl)methallylamide
Matt Flynn, Victoria Blair, Rachel Stott, Phil Andrews
Metallated derivatives of (S)-N-(α- methylbenzyl)methallylamine have been produced to investigate anion rearrangements analogous to those of the related allylamine.
P7 Novel Structures of Naphthyl Lithium Amides
Greer, J. Andrews, P. Blair, V
Structural characterisation of intermediates leading to a trilithiated naphthyl amide complex. Also, further donor studies resulted in the characterisation of an unexpected amido lithate complex.
P8 Bioorganometallic Complexes as Anti-Cancer and Anti-Tuberculosis Agents: Synthesis, Characterization and Biological Evaluation
C. Quintana, R. Arancibia, A. H. Klahn, M. Fuentealba, V. Artigas, L. Kremer
Bioorganometallic complexes of ferrocene and cyrhetrene as anti-cancer and anti- tuberculosis agents
P9 “Normalised” abnormal carbene palladium complexes
Catriona R. Vanston, T. P. Nicholls, M. G. Gardiner
We have prepared several “normalised” abnormal carbene palladium complexes using a biaryl ligand which may form a conjugate system.
P10
Synthesis and characterisation of novel di- BiPh BiPh2 BiLn BiLn 2 and tri-bismuth(III) aromatic compounds and evaluation of their anti-Leishmanial activity LH BiL BiPh2 n 2 5 BiL K. J. Burke, V. L. Blair, P. C. Andrews BiPh2 n 1 BiPh2 4 BiLn
L = select thiocarboxylates, thiolates, and carboxylic The synthesis of novel di- and tri-bismuth(III) acids
L Bi BiLn aromatic compounds for use as potential anti- Ph2Bi BiPh2 n 3 6 Leishmanial agents is presented.
P11 Selenium-interrupted carbochain bridged bimetallics
Richard Manzano, Tim Evers, Anthony Hill, Jas Ward
A number of dimetallapolycarbyl complexes containing selenium interrupted polycarbyl chains has been synthesised through a number of subsequent reactions.
P12 Divalent Lanthanoid Complexes of Bulky Amide Ligands
Caspar de Bruin-Dickason, Glen Deacon, Cameron Jones*
Very bulky monodentate amides ligands have been explored as ligands for divalent lanthanoid and alkaline earth complexes.
P13 Diastereoselective and Regioselective OH R ∗ CHO Allenylation of Chiral Amino Aldehydes + Et2Zn R ∗ ∗ NBnBoc Bpin toluene, 0 oC F. Zamani, S. G. Pyne, C. J. T. Hyland NBnBoc • 8 examples • High yields The first example of diastereoselective • Excellent regioselectivity • Excellent diastereoselectivity allenylation of chiral carbonyl compounds using • No additives or ligands Et2Zn as catalyst has been reported.
P14 Ancillary Ligand Effects in Donor-Acceptor Re(CO)3(dppz) Complexes
C. B. Larsen, H. van der Salm, N. T. Lucas, K. C. Gordon
n+ Effects of altering X in [Re(CO)3(dppz)(X)] complexes on the photophysical properties of sulfur- and amine-based donor-acceptor complexes are reported.
P15 A Dixanthene Scaffold for Cooperative Catalysis
Matthew Mudge, Alpesh Patel, Mohan Bhadbhade, Stephen Colbran
New ditopic ligands of a novel dixanthene scaffold that expedite the syntheses of bimetallic catalysts with co-facing metal centres, and their monomeric analogues, are described.
P16 Organo-transition metal complexes for electrocatalyic reduction of carbon dioxide
Lida Ezzedinloo, Mohan M. Bhadbhade, Stephen B. Colbran
Development of a catalytic system that can convert CO2 to value-added chemicals (e.g., HCHO) and fuels (e.g., MeOH) with high efficiencies is our goal.
P17 Dipyridylpyrrolato anion analogues of terpyridine metal complexes
James McPherson, Alex McSkimming, Mohan Bhadbhade and Steve Colbran
An easy one-pot synthesis of 2,5-di(2- pyridyl)pyrroles enables the development of anionic analogues of terpyridine and their metal complexes.
P18 Monodentate Ligands For The Stabilisation Of Two Coordinate Magnesium(I) Dimers
Aaron Boutland, Deepak Dange, Laurent Maron, Andreas Stasch, Cameron Jones
Utilising bulky monodentate amide ligands, a route to novel magnesium(I) dimers featuring magnesium in a two-coordinate environment is detailed. Novel dimers may have altered reactivity due to low coordination environment.
P19 Remarkable Thermal Stability of Gold Nanoparticles Utilising Organic and Inorganic Stabilisers
Andrew McDonagh, Shirin Rose King, Angus Gentle
High thermal stability of gold nanoparticles has been achieved using thermally robust stabilising molecules, which provide an effective barrier to sintering of the particles.
P20 Understanding N-Heterocyclic Carbene Properties
Christopher D. Barnett, Marcus L. Cole, Jason B. Harper The electronics of two series of NHCs have been probed for overall donation, σ-donation and π- accepting ability. An understanding of the origin of these properties has been gained and applied to some initial catalytic systems.
P21 Using Pincer Ligands to Study s- and p-Block Halides and Hydrides
Kai N. Buys, Marcus L. Cole Group 2
A study of the coordination chemistry of a Group 13 monoanionic bis(NHC)-carbazolide pincer ligand with s- and p-block metals. Group 14
P22 Effects of donor/acceptor geometry in organo- ruthenium cruciforms for NLO studies
Anthony Nolan, Mark G Humphrey, Marie. P. Cifuentes
3 isomeric organo-ruthenium cruciforms will be synthesised with varying geometries for the terminal donor/acceptor groups. The electronic and non-linear optical effects of these molecules will be compared.
P23 The Use of Electronically and Sterically Modified β-Diketiminates (NacNac-s) for Stabilising Low Oxidation Magnesium and Group 13 and 14 Complexes
Indrek Pernik, Dr. Andreas Stasch,* Prof. Cameron Jones*
Substitution of certain carbon atoms for nitrogens results in a NacNac ligand with substantially altered reactivity.
P24 6+ Synthesis of a family of [M2L3] helicates and mesocates derived from bis(bidentate) 2- pyridyl-1,2,3-triazole “click” ligands: Towards antimicrobial helicates
Roan Vasdev, Dan Preston, James Crowley
A family of Co(III) cylinders have been synthesised using various pyridyl-triazole ligands, working towards antimicrobial helicates.
P25 Ruthenium alkynyl cruciform and solubility corundum
Mahbod Morshedi, Ellen Phiddian, Marie P. Cifuentes, Mark G. Humphrey
Syntheses and optical properties of a series of donor-acceptor substituted 1,2,4,5- tetrakis(phenylethynyl)benzenes is described.
P26 The Kinetic Stabilisation of Main Group and Transition Metal Complexes with a Super Bulky Diiminopyridine
Vera Diachenko, Marcus Cole
A super bulky diiminopyridine has been developed for the kinetic stabilisation of group 13 and 14 complexes and first row transition metal complexes.
P27 Weak Te-Te Interactions in Naphthalene and related scaffolds K. S. Athukorala Arachchige, F.R. Knight, L. M. Diamond, M. Bühl, A.M.Z. Slawin, J.D. Woollins weak donor–acceptor interactions and the onset of 3-center-4-electron (3c4e) bonding in peri- substituted systems
P28 Synthesis of Novel Platinum Poly-ynes with Pendant Liquid Crystalline Cores
Muhammad Younus and Salhed Ahmed
The synthesis of a series of biphenyl based liquid crystals (LC), and their attachment into the platinum poly-ynes are described.
Nematic droplets with schlieren textures at 213 ºC
P29
Synthesis, characterisation and biological applications of haloformamidinatoantimony (III) complexes
A.Aldabbagh, Peter Junk, Jun Wang
Redox transmetallation/ligand exchange between a metal, a diarylmercurial, and a protonated ligand, has been successfully invested for the [1-5] lanthanoid elements, and for the more Crystal structure of synthesized [Sb(DippForm)(C6F5)X(thf)2] electropositive alkaline earth metals.
Fig1. Crystal structure of P30 synthesized[Sb(DippForm)(C6F5)X(thf)2] Synthesis of rare earth complexes involving N,N'-di(diphenyl)formamidine ligand
M. Salehisaki, P. C. Junk, J. Wang
As the results of the reactions between the RE elements and N,N'-diphenylformamidine (DiphFormH) ligand two new compounds of [Y(DiphForm)3(thf)2] and [Er(DiphForm)3(thf)] Figure 1. X-ray Structure of [Y(DiphForm)3(thf)2] (left) and were formed in good yields of 54% and 70% [Er(DiphForm)3(thf)] (right). respectively (Figure 1).
P31 Homo- and Heterobimetallic Complexes Used as Catalysts for a Range of Organic Transformations: Lessons Learned
Mark R. D. Gatus, Barbara A. Messerle
Homo- and heterobimetallic complexes used for C-X bond formation reactions and unusual reactivity of Ir(I) NHC complexes
P32 Synthesis of the First Reported Cyclic (alkyl)(amino)Carbene (CAAC)-Group 13 Metal (M= Al, Ga, or In) Complexes
Jacques Atkinson-Bodourian, Deepak Dange, Cameron Jones
Synthesis of cyclic (alkyl)(amino)carbene (CAAC)-group 13 metal (M= Al, Ga or In) complexes and their subsequent reduction.
P33 Photophysical trends in iridium(III) tetrazolate complexes
Chiara Caporale, Stefano Stagni, Max Massi
The photophysical properties of a family of iridium tetrazolate complexes can be easily tuned via chemical modifications of the ligands.
P34 Group 8 and 9 Complexes Bearing an Anionic Carbon Centred Podand Ligand
Samantha K. Furfari, Alison M. Magill, Ryan J. Gilbert-Wilson, Leslie D. Field
We are interested in exploring the reactivity of group 8 and 9 dinitrogen complexes with new anionic carbon centred podand ligands.
P35 Protonation of Dinitrogen to Ammonia on Ruthenium and Iron Complexes Containing Tripodal Phosphine Ligands
P. M. Abeysinghe, L. D. Field, H. L. Li, T. O. Peters, S. J. Dalgarno, R. D. McIntosh
R Treatment of [M(N2)(PP3 )] (M = Fe, Ru; R = iPr, Ph, Cy) with triflic acid afforded ammonium in yields ranging from 0 to 66%.
P36 Homoleptic Au(III) trications: A synthetic pathway to a novel class of Au(III) compounds
Robert Corbo, Thomas P. Pell, David J. D. Wilson, Peter J. Barnard and Jason L. Dutton*
Facile formation of a new class of Au(III) coordination complex utilizing I(III) as the terminal oxidant.
P37 Configuration-Dependent Kinetic Indenyl Effects in Metal-Centered Epimers of η5:κ2(C,S)-Indenyl-Phenethylsulfanyl Rhodacycles
Robert W. Baker
Substantial differences in the kinetics of ligand substitution are observed for metal-centered epimers of constrained geometry indenyl- rhodium(III) complexes.
P38 Tumour Selective Gadolinium Agents as Binary Cancer Therapies
A. J. Hall, M. T. Kardashinsky, L. M. Rendina
The synthesis and characterisation of new gadolinium(III)-containing agents for binary cancer therapies are described with a view towards improved complexation characteristics, efficacy and stability in a biological environment.
P39 New Platinum Octupolar Complexes for Nonlinear Optics
S. Streatfield, M.G. Humphrey, M.P. Cifuentes, F. Paul
A series of new platinum octupolar complexes with varying electronic nature and different aryl systems are reported.
P40 Utilising Bulky Monodentate Alkyl/Aryl Substituted Amido-Ligands to Stabilise Low Oxidation State Silicon Compounds
John Kelly, Cameron Jones
Utilisation of bulky alkyl/aryl amide ligands has resulted in the isolation of novel low oxidation state silicon compounds. These can be accessed faciley via dehydrohalogenation using an N- heterocyclic carbene (NHC).
P41
CAC vs. ACC (A= S, Se, Te, BOMe, SnMe2, PR; R = Cl, Ph, Cy) bridged bimetallics
Kassetra von Nessi, R. Manzano, A. Colebatch, Y.-S. Han, A. Hill, R. Shang, M. Sharma, J. Ward
Heteroacyl vs. bis(carbyne) preference for heteroatomically-bridged bimetallic carbyne complexes.
P42 Reduced group 2 diiminopyridine complexes: synthesis, structure and 2-electron reactivity
Mike Dawkins, Cameron Jones Ph Ph N Diiminopyridine ligands can exist in multiple states of reduction. We present a range of group N Mg N 2 complexes with differing ligand reduced states. dipp dipp Doubly reduced species [dimpyMg.OEt2] is able to activate a wide variety of small molecules. OEt2
P43 Photophysical and photochemical investigation of tricarbonyl rhenium(I) diimine and N-heterocyclic carbene complexes
Nurshadrina Akabar, Kimiko Uda, Garry Hanan and Max Massi.
The photophysical and photochemical properties of Re-NHC complexes will be presented in view of their potential use as photoCORMs.
P44 The divergent application of three-membered strained-ring systems in the palladium- catalysed ring-opening reaction
Yin Jie Xiang, Christopher Hyland The 3-membered strained rings such as aziridines and cyclopropanes underwent Friedel-Crafts reaction with indoles and ring-opening addition with arylboronic acids under catalysis of Pd, demonstrating strained-ring systems’ versatility.
P45 Ir(III)-1,2,4 triazole donor and Lanthanide acceptor for electrochemically sensitized luminescence Linh M Quan, Bradley D. Stringer, Conor F. Hogan, Peter J. Barnard
The synthesis, photophysical, and electrochemical characterization of the Ir(III) - 1,2,4 triazole complex coupled to DOTA macrocycle for the introduction of lanthanide ions are reported.
PLENARY LECTURE ABSTRACTS
PL1 Synthesis and Reactivity of Complexes Bearing Protic NHC Ligands
F. Ekkehardt Hahn Universität Münster, Department of Chemisty, Corrensstrasse 30, D-48149 Münster, Germany
Recently, it was discovered, that neutral azoles like N-methyl-2-chlorobenzimidazole1 or even 2- chlorobenzimidazole2 react with Ni0, Pd0 or Pt0 complexes under oxidative addition to give complexes of type 1 with an anionic NHC ligand featuring an unsubstituted ring-nitrogen atom. Protonation of such complexes yields complexes bearing NHC ligands with an NH,NR- or NH,NH-substitution pattern as in 2 and 3, respectively.
Reaction of 1 with dihydrogen leads to heterocyclic cleavage of H2 and formation of complex 4. The preparation of NHC complexes by oxidative addition of 2-halogenoazoles to transition metals together with the classical preparation of NHC complexes by deprotonation of azolium salts followed by NHC coordination allows for the selective preparation of heterobimetallic complexes and selected examples will be presented. The oxidative addition of 2-halogenoazoles to transition metals can be employed to generate carbene complexes by C-metalation of biomolecules like 8-bromocaffeine and 8-bromoadenine leading to complexes 5 and 6, respectively.3 Furthermore, the NH group of protic NHC ligands can act as recognition unit for selected substrates. Preorganization of substrates via formation of hydrogen bonds to NHC-NH groups of coordinated protic NHC ligand allows the regioselective catalytic hydrogenation of selected substrates. This and additional properties of complexes bearing protic NH,NH or NH,NR-NHC ligands including abnormal protic NHCs4 will be discussed.5
Acknowledgements: The author thanks the Deutsche Forschungsgemeinschaft (SFB 858, IRTG 2027) for financial support.
References: 1. (a) T. Kösterke, T. Pape, F. E. Hahn, J. Am. Chem. Soc. 2011, 133, 2112. (b) T. Kösterke, T. Pape, F. E. Hahn, Chem. Commun. 2011, 47, 10773. (c) T. Kösterke, J. Kösters, E.-U. Würthwein, C. Mück- Lichtenfeld, C. Schulte to Brinke, F. Lahoz, F. E. Hahn, Chem. Eur. J. 2012, 18, 14594. 2. (a) R. Das, C. G. Daniliuc, F. E. Hahn, Angew. Chem. Int. Ed. 2014, 53, 1163. (b) R. Das, H. Hepp, C. G. Daniliuc, F. E. Hahn, Organometallics 2014, 33, 6975. 3. D. Brackemeyer, A. Hervé, C. Schulte to Brinke, M. C. Jahnke, F. E. Hahn, J. Am. Chem. Soc. 2014, 136, 7841. 4. H. Jin, T. T. Y. Tan, F. E. Hahn, Angew. Chem. Int. Ed. 2015, in press, DOI: 10.1002/anie.201507206. 5. M. C. Jahnke, F. E. Hahn, Chem. Lett. 2015, 44, 226.
PL2 s-Block Metal Hydride Complexes: Syntheses, Properties and Applications
A. Stasch School of Chemistry, 17 Rainforest Walk, Clayton Campus, Monash University, Melbourne, VIC 3800, Australia; [email protected]
The s-block metals (Alkali metals, Alkaline Earth metals) are the most electropositive elements in the periodic table. In their binary compounds with hydrogen, the large electronegativity difference between the elements leads to metal hydrides with ionic or "saline" properties incorporating hydride anions. The s-block metal hydrides are of importance as reagents in synthetic transformations such as hydride transfer and reductions, in catalysis, and for hydrogen storage applications. The metal hydride solids are generally insoluble and thus show relatively low reactivity. Recent years have seen advances in the development of soluble, well-defined s-block metal hydride complexes because synthetic routes are emerging, and suitable stabilizing ligand systems have been studied and employed. These systems show different properties compared with their bulk metal hydrides.[1,2] This presentation will give an account of the syntheses, stabilization and characterization of these species and highlight some challenges for this science. In the few past years, several novel s-block metal hydride species have been synthesized and these range from small monohydride compounds to large metal hydride clusters (see pictures for Alkali metal examples). Both the stoichiometric and catalytic reactivity of these s-block metal species will be presented.
[Na7H(pz)6] (core) [Li8H4(Ph2PNDip)4] [Li37H25(pz)12]
(pz = 3,5-di-tert-butylpyrazolate; Dip = 2,6-iPr2C6H3)
Acknowledgements: We thank the Australian Research Council for support, the Australian Synchrotron and Monash University.
References: 1. S. Harder, Chem. Commun., 2012, 48, 11165 (review). 2. L. Fohlmeister, A. Stasch, Aust. J. Chem., 2015, 68, 1190 (review).
PL3 Application of cationic phosphanes
J. J. Weigand Department of Chemistry and Food Chemistry, Chair of Inorganic Molecular Chemistry, TU Dresden, 01162 Dresden, Germany, email: [email protected]
Phosphorus based compounds exhibit a rich chemistry due to their ability to stabilize both negative and positive charges. Trivalent phosphorus derivatives have proven to be exceptionally powerful in main group chemistry[1] and homogeneous catalysis.[2] Potential areas of application range from the use as ligands through a key role in biological systems to valuable catalytically active systems. In this contribution we report on the synthesis and application of novel imidazoliumyl substituted phosphorous based cations bearing highly electronegative groups, such as cationic imidazoliumyl substituents.[3-5] Due to their unique electronic structure the imidazoliumyl substituents are capable of stabilizing hyper- as well as low-coordinated P-atoms leading unique properties of the resulting phosphanide and fluorophosphonium salts. Initial applications of this promising substance classes as organocatalysts, ligands in homogeneous catalysis and ligands for transition metal complexes will be presented.
References: 1. K.-O. Feldmann, J. J. Weigand; Angew. Chem. Int. Ed., 2012, 51, 6566. 2. Z. Wang, X. Xu, O. Kwon, Chem. Soc. Rev. 2014, 43, 2927. 3. K. Schwedtmann, M. H. Holthausen, K-O Feldmann, J. J. Weigand, Angew. Chem., Int. Ed. 2013, 52, 14204. 4. K. Schwedtmann, S. Schulz, F. Hennersdorf, T. Strassner, E. Dmitrieva, J. J. Weigand; Angew. Chem. Int. Ed., 2015, 54, 11054.
Acknowledgement: This work was supported by the Fonds der Chemischen Industrie (FCI), the German Science Foundation (DFG, WE 4621/2-1) and the ERC (SynPhos 307616).
PL4 Catalysts for a more sustainable chemistry
Rhett Kempe Lehrstuhl für Anorganische Chemie II – Katalysatordesign, Universität Bayreuth, Germany, [email protected]
Dwindling reserves of crude oil and other fossil carbon sources combined with environmental concerns have resulted in a call for the use of alternative, preferably renewable, resources. Aside from fuel, ultimately a wide variety of chemical feedstocks is derived from fossil sources. Renewable lignocellulosic materials or waste are abundantly available,1 indigestible and therefore not useful as food products, and can be processed to give alcohols and polyols.2 Thus, there is a high demand for new reactions that utilize alcohols and convert them into key chemicals.3 Recently, our group introduced the concept of acceptorless dehydrogenative condensations (ADC) for the catalytic synthesis of important aromatic N-heterocyclic compounds like pyrroles 3 and pyridines. 4 In such ADC reactions, alcohols become selectively hetero-connected via C-C and C-N bond formation steps. The deoxygenation of alcohols takes place via condensation steps and liberation of H2 leads to aromatization. In the talk, the development of (i) the ADC concept, (ii) novel ADC reactions,5 (iii) robustly supported reusable catalysts for ADC, (iv) base metal catalysts,6,7 and (v) novel catalytic concepts possible due to progress made in ADC recently, are discussed.
References: 1. C. O. Tuck, E. Perez, I. T. Horvath, R. A. Sheldon, M. Poliakoff, Science, 2012, 337, 695. 2. a) T. P. Vispute, H. Zhang, A. Sanna, R. Xiao, G. W. Huber, Science, 2010, 330, 1222. b) M. Zaheer, R. Kempe, ACS Catal,. 2015, 5, 1675. 3. S. Michlik, R. Kempe, Nature Chem., 2013, 5, 140. 4. S. Michlik, R. Kempe, Angew. Chem. Int. Ed., 2013, 52, 6326. 5. N. Deibl, K. Ament, R. Kempe, J. Am. Chem. Soc., 2015, 137, 12804. 6. S. Rösler, J. Obenauf, R. Kempe, J. Am. Chem. Soc., 2015, 137, 7998. 7. S. Rösler, M. Ertl, T. Irrgang, R. Kempe, Angew. Chem. Int. Ed., 2015, 54, DOI: 10.1002/anie.201507955.
ORAL LECTUREORAL ABSTRACTS
OL1 Design, Synthesis, and Reactivity of Organometallic Ni(IV) Complexes
Nicole M. Camasso,1 James R. Bour,1 Allan J. Canty,2 Melanie S. Sanford1 1University of Michigan, Department of Chemistry, 930 N. University Ave., Ann Arbor, MI 48109, USA. email: [email protected] 2University of Tasmania, School of Chemistry, Private Bag 75, Hobart, Tasmania 7001, Australia.
Transition metal–catalyzed cross-coupling reactions are widely used synthetic methods for the construction of carbon-carbon and carbon-heteroatom bonds, the importance of which was recognized with the Nobel Prize in chemistry in 2010. While the vast majority of these transformations use palladium-based catalysts, over the past decade there has been a resurgence in the development of nickel-catalyzed cross-coupling reactions.1 Nickel catalysts offer the advantage of being more sustainable and economical than their palladium analogs.1 In addition, the intrinsic properties of nickel can enable transformations that are challenging with palladium catalysts. For example, nickel catalysts can promote cross-coupling reactions that use tertiary alkyl halides2 or phenol derivatives3 as electrophiles. Mechanistic studies have suggested that these reactions generally proceed via Ni intermediates in the 0, +1, +2, and/or +3 oxidation states.4 In contrast, organometallic Ni(IV) intermediates are rarely invoked in catalysis. Importantly, if such intermediates are accessible they have the potential to exhibit complementary reactivity profiles compared to their lower valent Ni counterparts. We report the design and synthesis of a series of organometallic Ni(IV) complexes accessed by the 2e– oxidation of Ni(II) precursors with S-(trifluoromethyl) dibenzothiophenium triflate as well as with diaryliodonium and aryl diazonium reagents.5,6 The reactivity of these complexes toward carbon(sp3)-heteroatom, and carbon(sp2)- trifluoromethyl bond forming reactions are discussed. Notably, these transformations are extremely challenging to achieve at lower valent Ni centers. Thus, the observed reactivity has the potential for direct applications in the development of novel nickel-catalyzed cross-coupling reactions.
H N H H N B B N B N N N N N N CF + Nuc– N 3 N N CF 3 II IV II 3 C(sp )–heteroatom N Ni Ni N Ni N N N N coupling
CF3 Nuc
H H N B N H N B N N B N N CF + N Aryl+ N 3 N CF N CF IV 3 N CF II 3 N Ni II 3 N Ni N CF N Ni N Aryl 3 N CF Aryl 3
2 C(sp )–CF3 coupling
Aryl CF3
Acknowledgements: This work was supported by the National Science Foundation Grant CHE-1111563. References: 1. S. Z. Tasker, E. A. Standley, T. F. Jamison, Nature, 2014, 509, 299. 2. S. L. Zultanski, G. C. Fu, J. Am. Chem. Soc., 2013, 135, 624. 3. B. M. Rosen, K. W. Quasdorf, D. A. Wilson, N. Zhang, A. M. Resmerita, N. K. Garg, V. Percec, Chem. Rev., 2011, 111, 1346. 4. X. Hu, Chem Sci., 2011, 2, 1867. 5. N. M. Camasso, M. S. Sanford, Science, 2015, 347, 1218. 6. J. R. Bour, N. M. Camasso, M. S. Sanford, J. Am. Chem. Soc. 2015, 137, 8034.
OL2 The Synthesis and Switching of a Molecular Folding Ruler
Synøve Ø. Scottwell, James D. Crowley The Department of Chemistry, the University of Otago [email protected]
Nature is the undisputed master of molecular mechanics,1 and inspired by these biological feats, chemists are now attempting to create nanoscopic synthetic analogues from the “bottom up”, including molecular “muscles”/actuators.2 Initially, this was attempted using mechanically interlocked architectures,3 however, these architectures tend to be synthetically challenging with disappointingly low overall yields, thus the rising popularity of the comparatively simple non-interlocked architectures. A number of approaches have been attempted, including the use of carbon nanotubes,4 polymers,5 and oligomers, and it is this last group in which we have an interest.
Our work is inspired by Bosnich’s ferrocene-based two-state switch,6 and we have recently reported the successful synthesis and reversible switching of a ferrocene-based actuator.7 The larger “folding ruler” that has since been developed will be presented.
References: 1. K. Kinbara, and T. Aida, Chem. Rev., 2005, 105, 1377-1400. 2. D. Li, W. F. Paxton, R. H. Baughman, T. J. Huang, J. F. Stoddart, and P. S. Weiss, MRS Bull., 2009, 34, 671-681. 3. J.-P. Sauvage, J.-P. Collin, S. Durot, J. Frey, V. Heitz, A. Sour, and C. Tock, C. R. Chimie, 2010, 13, 315- 328. 4. R. H. Baughman, C. Cui, A. A. Zakhidov, Z. Iqbal, J. N. Barisci, G. M. Spinks, G. G. Wallace, A. Mazzoldi, D. De Rossi, A. G. Rinzler, O. Jaschinski, S. Roth, and M. Kertesz, Science, 1999, 284, 1340- 1344. 5. M. Numata, D. Kinoshita, N. Hirose, T. Kozawa H. Tamiaki, Y. Kikkawa, and M. Kanesato, Chem. Eur. J., 2013, 19, 1592-1598; M. Shibata, S. Tanaka, T. Ikeda, S. Shinkai, K. Kaneko, S. Ogi, and M. Takeuchi, Angew. Chem. Int. Ed., 2013, 52, 397-400. 6. J. D. Crowley, I. M. Steele, and B. Bosnich, Chem. Eur. J., 2006, 12, 8935-8951. 7. S. Ø. Scottwell, A. B. S. Elliott, K. J. Shaffer, A. Nafady, C. J. McAdam, K. C. Gordon, J. D. Crowley, Chem. Commun., 2015, 51, 8161-8164.
OL3 Syntheses and Reactivity of New Formamidinate Rare Earth Metal Complexes from Pseudo-Grignard Reaction
Safaa Ali1, Peter Junk1 and Jun Wang2
[email protected] 1College of Science, Technology & Engineering, Building 21, James Cook University,Townsville, Qld, 4811, Australia. 2School of Chemistry, Monash University, Victoria, Australia
[1, 2] Pseudo-Grignard reagents , ‘‘RLnX’’ (Ln = Eu and Yb; R = Me, Ph or C6H2Me3-2, 4, 6; X = Br, I), formed by the treatment of organic halides like PhBr or PhI with rare earth metals in Lewis base solvents, can be employed to various organic or inorganic transformations[3, 4]. We now report the synthesis of new divalent rare earth metal formamidinate complex [Ln(Form)X(thf)2]2 through the relevant Pseudo-Grignard reactions of rare earth metal with bromobenzene and iodobenzene in the presence of formamidine species (Eq. 1). N,N’-Bis(aryl)formamidines (ArN=CH–NHAr (Ar = aryl)) (Fig. 1.), can be easily synthesised in high yields by heating to reflux one equivalent of triethyl orthoformate with two equivalents of the appropriate substituted aniline in the presence of acetic acid (Eqn. 2.) [5].
(Fig. 1) A typical reaction of pseudo-Grignard. Lanthanoid complexes have been reactivity with different kinds of ketones and aldyhades (Eqn. 3).
References
1.Syutkina, O. P.; Rybakova, L. F.; Petrov, E. S.; Beletskaya, I. P., J. Organomet. Chem., 1985, 280, C67. 2. Petrov, E. S.; Roitershtein, D. M.; Rybakova, L. F., J. Organomet. Chem., 2002, 647, 21. 3. Evans, D. F.; Fazakerley, G. V.; Phillips, R. F., J. Chem. Soc. D., 1970, 244. 4. Evans, D. F.; Fazakerley, G. V.; Phillips, R. F., J. Chem. Soc. A., 1971, 1931. 5. Roberts, R. M., J. Org. Chem., 1949, 14, 277.
OL4 A theoretical exploration into highly stabilized, non-Lewis acidic, anti-aromatic
beryllium ring systems
Terri E. Field-Theodore, David J. D. Wilson* and Jason L. Dutton*
Department of Chemistry and Physics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, Victoria, Australia
*[email protected], [email protected]
We present a theoretical investigation on a set of “Beryloles” - beryllium containing rings and anionic analogues of anti-aromatic boroles and the cyclopentadienyl cation.1-4 Due to the high toxicity of the beryllium, computational studies are attractive in predicting potentially interesting targets.5-6 Our calculations indicate that this family of Be ring compounds should be electronically viable (as assessed from HOMO-LUMO and singlet- triplet gaps) and hence potential targets for synthetic chemists with appropriate skills. In strong contrast with boroles, the Be analogues are predicted to have no Lewis acidic tendencies, but rather possess strong Lewis basic character. Nucleus-independent chemical shift (NICS) calculations indicate these species are anti-aromatic in character, albeit somewhat less than the most common borole rings.1
Acknowledgements: We thank The La Trobe Institute for Molecular Science for their generous funding of this project. Grants of computing resources from VPAC and NCI-NF are acknowledged. This work is also supported by an ARC DECRA fellowship (JLD, DE130100186).
References: 1. Field-Theodore, T.E.; Wilson, D.J.D.; Dutton, J.L, Inorg Chem., 2015, 54, 8035. 2. Braunschweig, H.; Kupfer, T. Chem. Commun. 2011, 47, 10903. 3. Lambert, J. B.; Lin, L.; Rassolov, V. Angew. Chem. Int. Ed. 2002, 41, 1429. 4. Lambert, J. B. Angew. Chem. Int. Ed. 2002, 41, 2278. 5. Parameswaran, P.; De, S. Dalton Trans. 2013, 42, 4650. 6. Qiu, Y.; Sokolov, A. Y.; Yamaguchi, Y.; Schaefer, H. F. J. Phys. Chem. A 2013, 117, 9266.
OL5 Lanthanoid β-triketonate assemblies with improved near-infrared emission
Laura Abad Galán a, Brodie L. Reid a, Mark I. Ogden a, Eli Zysman-Colman b, Max Massi a
a Department of Chemistry, Curtin University, Perth, Australia. [email protected] b Organic Semiconductor Centre, EaStCHEM School of Chemistry, University of St Andrews, St Andrews, Fife, UK
Lanthanoid complexes have been widely studied for their characteristic sharp and long-lived line-like emission. There has been notable interest in the design of luminescent lanthanoid metal complexes for applications in bioimaging, solar cells, and visible organic light emitting devices (OLEDs).1 In comparison, near-infrared emitting OLEDs (NIR-OLEDs) have received less attention. We have been studying luminescent lanthanoid β-triketonate complexes and their applicability in OLEDs and NIR-OLEDs. Although there are many reports of lanthanoid complexes with β-diketonate ligands, the coordination of β-triketonate ligands to lanthanoids is relatively unexplored.2-3 We have been working with different β-triketonate ligands, various co-ligands and alkali metals, in order to study differences in the structure of the resulting lanthanoid complexes, and the effect on their visible and NIR photophysical properties. The results indicate that β-triketonate ligands are able to form complexes and assemblies of the lanthanoids with remarkable NIR emission, which rival previously reported species where ligands were perfluorinated or deuterated to minimise quenching.
LH O
O
O
{(Cs)[Yb(L) ]} [Yb(Phen)(L) ] 4 n 3 Acknowledgements:
L.A.G. thanks Curtin University for the International Postgraduate Research Scholarships and Curtin Strategic International Research Scholarship. References
1. de Bettencourt-Dias, A., Lanthanide-based emitting materials in light-emitting diodes. Dalton Trans. 2007, (22), 2229-2241.
2. Reid, B. L.; Stagni, S.; Malicka, J. M.; Cocchi, M.; Hanan, G. S.; Ogden, M. I.; Massi, M., Lanthanoid [small beta]-triketonates: a new class of highly efficient NIR emitters for bright NIR-OLEDs. Chem. Commun. 2014, 50 (78), 11580-11582. 3. Reid, B. L.; Stagni, S.; Malicka, J. M.; Cocchi, M.; Sobolev, A. N.; Skelton, B. W.; Moore, E. G.;Hanan, G. S.; Ogden, M. I.; Massi, M. Chem. Eur. J. 2015, DOI:10.1002/chem201502536.
OL6 Developing the Chemistry of N-2,6-terphenyl Substituted N-Heterocyclic Carbenes
Daniel Twycross, Marcus L. Cole University of New South Wales, [email protected]
Since their discovery, N-heterocyclic carbenes (NHCs) have excelled as support ligands in transition metal catalysis and as lewis base donors for main group elements. Their successes can be attributed to their ability to stabilise a diverse array of frail coordination environments, reactive metal fragments and otherwise inaccessible oxidation states, all of which are typically aided by bulkier ligand frameworks. Indeed, bulkier NHCs have promoted some of the most challenging catalytic transformations to date and contributed substantially to the isolation of rare or unprecedented main group species. This contribution presents our recent development of two bulky 2,6-terphenyl substituted NHCs (IDitop and IDitot), an evaluation in steric flexibility, progress towards the stabilisation of some group 13 trihalides and trihydrides and their application to palladium catalysed C-C bond formations.
Some Metal Complexes Supported by IDitop and IDitot
Acknowledgements: The authors would like to acknowledge the Australian Research Council for partial funding of this research (DP110104759). References: 1. Chartoire, A.; Lesieur, M.; Falivene, L.; Slawin, A. M. Z.; Cavallo, L.; Cazin, C. S. J.; Nolan, S. P. Chem.--Eur. J. 2012, 18, 4517. 2. Ball, G. E.; Cole, M. L.; McKay, A. I. Dalton Trans. 2012, 41, 946.
OL7 Third-order nonlinear optical properties of Group 8 metal alkynyl complexes containing
fluorenyl moieties
A. Triadon,1,2 F. Malvolti,1 G. Grelaud,1,2 G. J. Moxey,2 A. Barlow,2 F. Paul,1 O. Mongin,1 M. P. Cifuentes,2 M. G. Humphrey2 1 Institut des sciences chimiques de Rennes UMR 6226, Campus de Beaulieu Université de Rennes 1 35042 Rennes, France 2 Research School of Chemistry, Australian National University, Canberra, ACT 2601, Australia [email protected]
Group 8 Organometallic complexes, particularly metal acetylides have been shown to have high nonlinear optical activity1. With careful choice of the ligand these organometallic centers act as donors and are often stable under two distinct redox states, allowing for commutation of their nonlinear optical properties2. The fluorene unit has been incorporated in multiple organic and organometallic molecular assemblies and is a well-known NLO-phore for third order nonlinearity3. A range of ruthenium and iron complexes were synthesized and their optical and nonlinear optical properties were assessed by spectroscopic method (CV, UV, SpecEchem, Z-scan).
Acknowledgements: Region Bretagne, ARC References: 1. Green, K. A.; Cifuentes, M. P.; Samoc, M.; Humphrey, M. G. Coord. Chem. Rev., 2011, 255, 2025. 2. Coe, B. J.; Acc. Chem. Res., 2006, 39, 383. 3. Rouxel, C.; Charlot, M.; Mir, Y.; Frochot, C.; Mongin, O.; Blanchard-Desce, M.; New J. Chem., 2011, 35, 1771
OL8 Azavinylidene Complexes of Metalloporphyrins and Metallophthalocyanines
Jie-Sheng Huang,* Kwok-Ming Wong, Wai-Man Tsui, Ken Chi-Hang Tso, Chi-Ming Che* Department of Chemistry and State Key Laboratory of Synthetic Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong. E-mail: [email protected]
Metal azavinylidene (M−N=CR1R2) complexes have received much attention due to their involvement in catalysis and their intriguing structures and reactivities. We have been endeavoring to develop the chemistry of metal azavinylidene complexes supported by macrocyclic chelating ligands including porphyrins and phthaocyanines.1,2 These macrocyclic tetradentate ligands have been found to well support the formation of trans-bis(azavinylidene) complexes of a high-valent transition metal, as well as trans-bis(imine) and trans-bis(secondary amine) complexes of low-valent transition metals. A synthetic route to metal azavinylidene complexes by oxidative deprotonation of metal imine complexes with a hypervalent iodine compound has been developed; such reaction provides useful insight into the mechanism of related nitrene transfer reactions mediated/catalyzed by metal complexes. The trans- bis(azavinylidene) complexes of metalloporphyrins or metallophthalocyanines exhibit a number of unprecedented spectral/structural features and/or reactivities. Attempts to extend similar chemistry to other types of cyclic chelating ligands, such as cuboidal Fe3S4 clusters as inorganic cyclic tridentate ligands, are also discussed.
Acknowledgements: This work was supported by Hong Kong Research Grants Council (HKU 702312P) and The University of Hong Kong (Seeds Funding for Basic Research).
References: 1. W.-M. Tsui, J.-S. Huang, G. S. M. Tong, S. C. F. Kui, C.-M. Che, N. Zhu, Chem. Asian J., 2010, 5, 759. 2. J.-S. Huang, K.-M. Wong, S. L.-F. Chan, K. C.-H. Tso, T. Jiang, C.-M. Che, Chem. Asian J., 2014, 9, 338.
OL9 Coupling Reactivity of Carbon Dioxide and Acetylene Mediated by Iron Phosphine
Complexes
Peter M. Jurd,1 Leslie. D. Field,1 Mohan M. Bhadbhade,2 Scott J. Dalgarno3 1School of Chemistry, University of New South Wales, Sydney, Australia 2 Mark Wainwright Analytical Centre, University of New South Wales, Sydney, Australia 3 School of Engineering and Physical Sciences – Chemistry, Heriot-Watt University, Edinburgh, U.K Email: [email protected]
The utilisation of carbon dioxide as a chemical feedstock in the synthesis of fine chemicals presents an attractive approach to emissions mitigation. However, due to the high thermodynamic stability of carbon dioxide, there are currently few viable industrial processes capable of utilising the compound on a meaningful scale.1
The inherent stability of carbon dioxide may however be overcome through the use of transition metal complexes, allowing for subsequent reaction with organic substrates. Use of energetic unsaturated organic substrates such as alkynes can further facilitate reactivity, providing a synthetic route to 2-pyrones2 and products bearing α,β- unsaturated carboxylic acid functionalization.3
In this work, the reaction of carbon dioxide toward acetylene mediated by the iron phosphine complexes
[Fe(dmpe)2] and [Fe(depe)2] (dmpe = 1,2-bis(dimethylphosphino)ethane, depe = 1,2-bis(diethylphosphino)ethane) is found to exhibit differing synthetic outcomes based upon CO2 substrate pressures (Figure 1). Herein we present efforts to gain mechanistic insight into these outcomes in order to better understand patterns of reactivity.
Figure 1: Reaction of iron hydrido acetylide complexes toward carbon dioxide at varied substrate pressures resulting in differing synthetic outcomes
Acknowledgements: UNSW for funding.
References:
1. M. Aresta, A. Dibenedetto, and A. Angelini, Chem. Rev., 2013, 114, 1709–1742. 2. Y. Inoue, Y. Itoh, and H. Hashimoto, Chem. Lett., 1977, 6, 855–856. 3. K. Shimizu, M. Takimoto, Y. Sato, and M. Mori, Org. Lett., 2005, 7, 195–197.
OL10 Formation of bulky amido stabilised dipnictenes via highly reactive pnictinidene intermediates
Amelia Davey and Prof. Cameron Jones* School of Chemistry, Monash University, Clayton, VIC, 3800. Email: [email protected], [email protected]
Since the isolation of the first stable diphosphene in 1981,1 interest in the synthesis of low oxidation state group 15 compounds has increased greatly, with many dipnictenes having been isolated.2 In the Jones group, a series of extremely bulky amido ligands have been used to kinetically stabilise a number of low oxidation state main group 3,4 complexes. Using one such ligand, a range of bulky amido pnictogen dihalide complexes, LEX2 (E = P, As, Sb, Bi, X = Cl, Br) have been isolated as potential precursors for low oxidation state chemistry.5
The reduction of the precursors has produced a range of novel compounds, where the final structure is highly dependent on the size of the group 15 element used (Figure 1). The reduction of the smallest pnictogen precursor complex, LPCl2, led to the isolation of two distinct products; the C-H activated product (1), and the [2+1]- cycloaddtion product (2). In contrast, the reduction of the heavier pnictogen precursor complexes (LEX2, E = Sb,
Bi, X = Cl, Br), formed the more common dipnictidene species (3). Remarkably, the reduction of LAsCl2 gave both the [2+1]-cycloaddtion product (2), and the element(I) dimer (3). It has been proposed that all of these reductions proceed via a highly reactive pnictinidene intermediate, which further undergoes an intra- or intermolecular reaction to give the isolable product.
- H L= Ar*(SiPh3)N Ph Si 3 E Ar*= 2,6-(C(H)Ph2)-4-Me-C6H2 N (1) X= Cl, Br Ph Ph Ph Ph mesNacnac= [(MesNCMe) CH]- 2 Ph3Si E= P Ph Ph N mes E (2) ( NacnacMg)2 E= P, As Ph LEX2 L-E Ph Ph Ph Ph Ph N Ph E E= As, Sb, Bi SiPh 3 Ph SiPh N Ph 3 E E Ph N Ph Ph Si 3 (3) Ph Ph
Figure 1. Proposed synthetic route to C-H activated product (1), [2+1]-cycloaddition products (2) and element(I) dimers (3).
References
1. M. Yoshifuji, I.Shima, N. Inamoto, K. Hirotsu, T. Higuchi, J. Am. Chem. Soc., 1981, 103, 4587. 2. T. Sasamori, N. Tokitoh, Dalton Trans., 2008, 11, 1395. 3. L. Jiaye, C. Schenk, C. Goedecke, F. Gernot, C. Jones, J. Am. Chem. Soc., 2011, 133, 18622. 4. D. Dange, A. Schwarz, D. Vidovic, C. Jones, N. Kaltsoyannis, P. Mountford, S. Aldridge, J. Am. Chem. Soc., 2012, 135, 6500. 5. D. Dange, A. Davey, J. Abdalla. S. Aldridge, C. Jones, Chem. Commun., 2015, 51, 7128.
OL11 Electrochemical investigation of [Co4(µ3-O4)(µ-OAc)4(py)4] and peroxides by
cyclic voltammetry
Edwin B. Clatworthy, Xiaobo Li, Anthony F. Masters and Thomas Maschmeyer Laboratory of Advanced Catalysis for Sustainability, School of Chemistry, The University of Sydney, Sydney, NSW 2006, Australia
The development of artificial photosynthesis for photocatalytic H2 production is highly desirable for the fulfilment of future energy demand; however the lack of highly efficient water oxidation catalysts (WOCs) is the main obstacle. Inspired by the Mn3Ca(µ-O)4 cubane structure of the oxygen evolution catalyst (OEC) found in photosystem II, investigations of OECs with analogous cubane motifs have attracted considerable attention and several reports of the water oxidation reaction (WOR) catalysed by molecular complexes with a cubane motif have appeared recently. In particular, the Co(III) complex, [Co4(µ3-O)4(µ-OAc)4(py)4] (1) and its derivatives have received considerable attention. Initial reports claimed 1 and its derivates were WOCs, however subsequent investigation by other researchers has found that this is in fact not the case.1 It was postulated that if 1 were to be a WOC, it would require a more highly oxidised species than previously reported.2 In this presentation we report the discovery of such a species and investigate its interaction with water and peroxides by use of cyclic voltammetry. Electrochemical methods such as cyclic voltammetry are used ubiquitously for screening and characterising potential catalysts for the WOR. Identifying available oxidation processes is critical in understanding the mechanisms responsible water oxidation and other potential applications in redox-mediated reactions.
Acknowledgements: The Australian Research Council and Australian Government (APA).
References:
1. A. M. Ullman, Y. Liu, M. Huynh, D. K. Bediako, H. Wang, B. L. Anderson, D. C. Powers, J. J. Breen, H. D. Abruña and D. G. Nocera, Journal of the American Chemical Society, 2014, 136, 17681-17688. 2. P. F. Smith, C. Kaplan, J. E. Sheats, D. M. Robinson, N. S. McCool, N. Mezle and G. C. Dismukes, Inorganic Chemistry, 2014, 53, 2113-2121.
OL12
Building blocks for organometallic polymers: spin-equilibrium behavior in some first
row transition metal anti-bimetallic complexes
Samantha C. Binding,1 Jennifer C. Green,2 and Dermot O’Hare2 1Macquarie University, North Ryde, Sydney, NSW 2109, [email protected] 2Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Oxford, UK
Organometallic polymers offer an opportunity to combine the physical properties of traditional polymers with the electronic, magnetic, redox, catalytic, and photoluminescence properties of transition metal complexes. Understanding how the substitution of peripheral groups and the choice of metal atom effects the electronic structure of the repeating unit within a metallopolymer will allow their properties to be tailored to specific end uses.
2- 2- The highly symmetrical, aromatic, bicyclic hexamethylpentalenyl dianion, (C8Me6 , Pn* ) is a purely hydrocarbon, π-bridging ligand. A series of homobimetallic complexes with cyclopentadienyl or permethylcyclopentadienyl capping groups have been developed, as well as monometallic hydropermethylpentalene sandwich complexes. A thorough characterisation study has been paired with a DFT examination of the solid state structures of the bimetallics to reveal the origin of changing spin-equilibrium behavior on traversing the series.
Acknowledgements: We thank SCG Chemicals Co., Ltd, Thailand for financial support
OL13 Design and Synthesis of a Novel Abnormal N–Heterocyclic Carbene Complex
Thomas P. Nicholls, C. R. Vanston, C. C. Ho, A. C. Bissember, M. G. Gardiner
School of Physical Sciences – Chemistry, University of Tasmania, Private Bag 75, Hobart, TAS 7001 Email: [email protected]
Recent work within our group has shown that electron-withdrawing substituents, such as an imidazolium ring on the C4 position of the imidazol-2-ylidene moiety can promote the lability of the C5 bound proton (Fig. 1). This suggests that abnormal complexation at this site may be enhanced. This led to the design of new ligands that mimic the electron-withdrawing nature of the C4 tethered imidazolium ring and exploit the lability of the C5 proton. We have been able to synthesise and crystallographically characterise an unprecedented abnormal N- heterocyclic carbene (aNHC) palladium complex (Fig. 2). Our preliminary studies suggest that resonance stabilisation involving the electron-withdrawing substituent on the aNHC ring has resulted in the removal of the formal negative charge from the aNHC ring. This means it loses its mesoionic character and no longer fits either definition of normal or abnormal NHC.
4 5 3 1 N N N N R N R 2 R R R 1 2 3
Figure 1: Examples of normal (1), abnormal (2) and remote (3) NHCs.
H3C N S
H3C I N Pd N N H3C I CH3 Figure 2: Novel abnormal N-heterocyclic carbene complex.
OL14 Modern Main-Group Chemistry: From Curiosity to Catalysis
Terrance J. Hadlington,1 and Cameron Jones1 1 Monash University, Wellington Road, Victoria, 3800.
Classically, main-group (MG) chemistry has been seen as relatively 1-dimentional in regards to its reactivity, with the exception of long known staples such as Grignard reagents and aluminium alkyl species. A renaissance in this area over the past 20 years has seen the characterisation of numerous examples of low oxidation-state MG species whose reactivity is in stark contrast to that previously known;[1] reactivity which has seen comparison to transition- metal (TM) chemistry.[2] The synonymous relationship between catalysis and TM chemistry, alongside recently reported similarities between TM and MG element chemistry, have led to hypotheses suggesting that catalysis can be performed by MG complexes. In this regard, we have synthesised low oxidation-state and low coordinate group
[3a] [3b] 14 element complexes capable of remarkable reactivity, such as the facile activation of H2, NH3, and other catalytically relevant small molecules including those containing unsaturated organic bonds (e.g. ethylene [3c]).
This reactivity has been extended to catalytic regimes, where by aldehydes, ketones, and CO2 have been catalytically reduced, for the first time by Ge(II) and Sn(II) species, using pinacol borane.[4] Development of the TBoN– ligand system (below) has now allowed for the activation of Si–H bonds by low coordinate Sn(II) centres, the oxidative addition of B–H bonds to related Ge(II) species, the reproducible synthesis of a novel [L4Sn6] cluster, and the isolation of the first example of a two-coordinate bis(amido) acyclic silylene, which undergoes facile NH3 activation.
TBoN HBpin Bpin Ge E = Ge, X = Et H TBoN Et
E X TBoN PhSiH3 TBoN: Pri H Sn E = Sn, X = OtBu Sn TBoN H N TBoN Pri Si B Oxidative Addition N – TBoN i N and Pr σ-Bond Metathesis i SiMe Pr 3 Acyclic, 2-Coordinate Bis(Amido) Silylene
LSn SnL Sn
LSn SnL Sn
(TBoN)6Sn4 Cluster L = TBoN
References: 1. Power, P. P., Acc. Chem. Res., 2011, 44, 627–637; Asay, M., Jones, C., Driess, M., Chem. Rev., 2011, 111, 354–396; Stephan, D. W., Erker, G., Angew. Chem. Int. Ed. 2010, 49, 46–76. 2. Power, P. P., Nature 2010, 463, 171–177. 3. (a) Hadlington, T., Herman, M., Li, J., Frenking, G., Jones, C., Angew. Chem. Int. Ed. 2013, 125, 10389– 10393; (b) T. J. Hadlington, M. Hermann, G. Frenking, and Cameron Jones, Chem. Sci., 2015, 10.1039/c5sc03376d; (c) T. J. Hadlington, J. Li, M. Hermann, A. Davey, G. Frenking, and C. Jones, Organometallics 2015, 34, 3175−3185. 4. Hadlington, T., Herman, M., Frenking, G., and Jones, C., J. Am. Chem. Soc. 2014, 136, 3028−3031.
OL15 Photophysical, Photochemical, and Biological Studies of Tricarbonyl Rhenium(I) N-
Heterocyclic Carbene Complexes
Peter Simpson,1 Brian Skelton,2 Paolo Raiteri,1 Annika Groß,3 Ingo Ott,3 Massimilliano Massi1 1 Department of Chemistry – Curtin University, Kent Street, Bentley 6102 WA, Australia. Email: [email protected] 2 Centre for Microscopy, Characterisation and Analysis, University of Western Australia, Crawley 6009 WA, Australia. 3 Institut für Medizinische und Pharmazeutische Chemie, Technische Universität Braunschweig, Beethovenstrasse 55, 38106 Braunschweig, Germany
Rhenium(I) complexes of the type fac-[Re(CO)3(diim)L], where diim represents a π-conjugated diimine ligand and L is a monodentate ancillary ligand, have been extensively studied due to their rich photophysical properties that give rise to phosphorescent decay typically from their lowest lying triplet metal-to-ligand charge transfer 3 1 excited state ( MLCT). Analogous complexes of the type fac-[Re(CO)3(NHC)L], where NHC represents a bidentate N-heterocyclic carbene ligand that binds the metal through an imine type N atom and the carbene C, have been considerably less studied despite the ubiquity of NHC ligands in inorganic chemistry. Complexes of NHC ligands have been used extensively as catalysts and are now even finding application as bioactive drugs against bacteria, parasites, and cancer.2 In this presentation, two small series of rhenium NHC complexes will be discussed. The first part will examine the synthesis, photochemistry, and structural and photophysical characterisation of Re(CO)3(NHC)L type complexes, where L = N3 or triazolate, the latter being prepared in a 1,3-dipolar cycloaddition from the azide complex. The second group of complexes contains triphenylphosphonium substituents on the NHC ligands, which serve as delocalized lipophilic cations that can cause a greater cellular uptake. Preliminary biological testing of two such complexes against some cancer lines and thioredoxin reductase, an important reductant enzyme in cells, will be presented.
Acknowledgements: This work is financially supported by the Australian Research Council
References: (1) Kirgan, R. A.; Sullivan, B. P.; Rillema, D. P. Top. Curr. Chem. 2007, 281, 45. (2) L. Oehninger, R. Rubbiani and I. Ott, Dalton Trans., 2013, 42, 3269–3284.
OL16 Ruthenium Complexes of Versatile 4,5-Diazafluoren-9-yl Ligands with Two
Coordination Sites
Max Roemer,1 Lesley Yie Ai Yong,1 Philip A. Schauer,1 Campbell F. R. McKenzie1, Laetia Le Gal,1 Siobhan Wills1, Brian W. Skelton1, George A. Koutsantonis*,1 1School of Chemistry and Biochemistry, M313, The University of Western Australia, 35 Stirling Hwy, Crawley, WA 6009, Australia; [email protected]
Transition metal complexes with multiple metal centers are highly desirable molecules for a variety of applications. These include nano electronics1, catalysis2 and photochemical switches3. Herewith we report on the preparation of several Ru complexes based on 4,5- diazafluoren-9-yl ligands with two coordination sites. Propargylic alcohols 1a and 1b are suitable for reaction with cis-Ru[Cl2(dppm)2] under presence of 4 NaPF6 to afford allenylidene derivatives 2a and 2b (Scheme 1).
+ R R PF N Ph2P PPh2 N 6 R = H (2a) HO Ru[Cl2(dppm)2] Cl Ru C C N DCM N N R = (2b) NaPF6 Ph2P PPh2 R R
R = H (1a) R = C5NH4 (1b)
Scheme 1. Preparation of ruthenium allenylidene complexes by reaction of cis-Ru[Cl2(dppm)2] and 1a and 1b.
Additionally, both ligands are suitable for coordination of the chelating bipyridyl (1a)5 or quaterpyridyl (1b) sites to a Ru center under the presence of a secondary N-heterocyclic ligand (Scheme 2).
2+ OH N N N RuCl2(bpy)2* 2H2O N Ru N EtOH/H2O HO N N N
Scheme 2. Complexation of 1a with Ru2+ under presence of two bipyridines as secondary ligands.
We have investigated allenylidene formation in the first step and coordination to the chelating moiety in the second step and the alternative strategy of coordination to the chelating moiety followed by allenylidene formation. Combination of both methods allows the preparation of bimetallic Ru-complexes. References: 1. P. J. Low, Dalton Trans., 2005, 17, 2821–2824. 2. D. G. McCollum, G. P. A. Yap, L. Liable-Sands, A. L. Rheingold, B. Bosnich, 1997, 36, 2230–2235. 3. O. S. Wenger, Chem. Soc. Rev., 2012, 41, 3772. 4. M. P. Cifuentes, M. G. Humphrey, G. A. Koutsantonis, N. A. Lengkeek, S. Petrie, V. Sanford, P. A. Schauer, B. W. Skelton, R. Stranger, A. H. White, Organometallics, 2008, 27, 1716–1726. 5. P. A. Schauer, B. W. Skelton, G. A. Koutsantonis, Organometallics, 2015, 34, 4975–4988.
OL17 Ru, Ni and Au Complexes of Hemilabile Pincer Ligands for Enhanced Catalysis
Ashwin Gopalan Nair ,1 Mark R. D. Gatus, 1 and Barbara A. Messerle 1 1 School of Chemistry and Biomolecular Sciences, Macquarie University, Sydney, NSW, 2109, Australia [email protected]
Incorporation of N-heterocyclic carbenes (NHCs) into a tridentate pincer ligand geometry with weakly coordinating side arm groups can lead to metal complexes that exhibit hemilabile equilibrium between tridentate and bidentate coordination modes. This ligand design can result in complexes with enhanced stability and catalytic activity due to the availability of vacant coordination sites for the substrate to interact with the metal centre.1 We have recently investigated the coordination chemistry of the pincer ligands 1 and 2 with Rh(I) and Ir(I) for catalytic transformations and found that the hemilability of the ligand enhances the catalytic activity of the complex.2 Here we present the coordination chemistry of pincer ligands 1 and 2 with Ru(II), Ni(II), Au(I) and Au(III) as well as the catalytic activity of the resultant Ru and Ni complexes containing ligands 1 and 2 for different organic transformations. These Ru(II) and Ni(II) complexes were found to be active catalysts for the transfer hydrogenation and the Kumada cross-coupling reactions respectively. Unlike the Ru(II) and Ni(II) complexes, Au(I) and Au(III) complexes containing the NCN ligand 1 adopt a monodentate geometry could allow addition of a second metal centre to the free pyrazole arms to produce hetero-bimetallic complexes.
References: 1 Yunshan S.; Christian K.; Runyu T.; Chem.Commun. 2011,47, 8349-8351.
2 Giulia Mancano, M. J. Page, Mohan Bhadbhade, and Barbara A. Messerle, Inorg. Chem., 2014, 53 (19), 10159–10170.
OL18 Uranyl(VI) Binding and Extraction by Bis(2-hydroxyaryl)diimine and Bis(2-
hydroxyaryl)diamine Ligand Derivatives
Kerstin Gloe, Karsten Gloe, Leonard F. Lindoy, Jan J. Weigand Department of Chemistry and Food Chemistry, TU Dresden, 01062 Dresden/Germany [email protected]
The coordination chemistry of multifunctional N,O-ligands has been the focus of a considerable number of investigations. We have employed a series of multifunctional diamine and related diamine ligand derivatives incorporating different bridges between nitrogen sites for the synthesis of crystalline supramolecular complexes as well as for solvent extraction studies using UO2(VI) as cation. The architectures obtained and the extraction behavior will be discussed in detail together with the factors influencing the processes.
X-ray structures of complexes of type [UO2(H2L)(NO3)2] show that each of these neutral ligands bind to their respective UO2(VI) centers in a bidentate fashion in which coordination only occurs via each ligand’s hydroxyl functions. Solvent extraction experiments (water/chloroform) employing different ligands in the organic phase and uranyl(VI)nitrate in the aqueous phase showed that amine derivatives yielded enhanced extraction of UO2(VI) over the corresponding imine derivatives. A very significant synergistic enhancement of the extraction of UO2(VI) by H2L was observed in the presence of a 10-fold excess of n-octanoic acid. A parallel set of experiments for europium(III)nitrate indicated a clear uptake preference for UO2(VI) over Eu(III) [1].
Acknowledgements: The authors thank the German Federal Ministry of Education and Research (BMBF – project 02NUK014A) and the European Research Council (ERC) (SynPhos project number 307616) for financial support.
References: 1. H. B. Tanh Jeazet, K. Gloe, T. Doert, J. Mizera, O. N. Kataeva, S. Tsushima, G. Bernhard, J. J. Weigand, L. F. Lindoy, K. Gloe, Polyhedron 2015, in press
OL19 Complexes of PSiP and N-Heterocyclic Carbene Pincer ligands
Chenxi Ma,1 Anthony F. Hill,1 Lily S. Dixon,1 Jas S. Ward1 1The Research School of Chemistry, The Australian National University, Acton 2601. [email protected]
By nature of their vacant coordination site, square planar (SP) 16 valence electron (VE) complexes are widely recognised for their potential as catalysts. Classic examples include the Monsanto and Cativa processes – 1 ([MI2(CO)2] , M = Rh, Ir respectively) in the production of acetic acid. In the economical pursuit of robust catalysts, pincer complexes have been thoroughly investigated for their thermodynamic stability and kinetically driven formation, both owing to the chelate effect.2
3 Coordination of pincer pro-ligands dihydroperimidene H2C(NCH2PR2)C10H6-1,8 (R = Ph, Cy) and 2,1,3- 4 benzosiladiazole HSiR(NCH2PPh2)2C6H4 (R = Ph, Cl) to iridium and rhodium metal substrates have been explored. Judicious choice of the metal substrate allows a variety of complexes to be generated from single, double or no C−H activation of the dihydroperimidene and Si−H activation of the benzosiladiazole rings. In particular, the formation of SP perimidenylidene N-Heterocyclic Carbene complexes was achieved via double C−H activation by appropriate iridium or rhodium precursors. In contrast, the benzosiladiazole ligand undergoes Si−H activation to rhodium followed by subsequent reductive elimination to afford the corresponding SP complex.
a) PR2 PPh2 N 0.5 Ir2Cl2(COD)2 N
CH2 C Ir Cl N Δ N - 2 COE PR2 PPh2
R = Ph, Cy
b) PPh2 PPh2
N RhH(PPh3)4 N H Si Si Rh PPh3 R - 3 PPh3 N N - H2 Ph PPh2 PPh2 R = Cl, Ph, Me Figure 1. Formation of 16VE pincer complex in the presence of a) Iridium via facile double C−H activation and b) Rhodium via Si−H activation.
References: 1. Jones, J. Platinum Metals Rev., 2000, 3, 94. 2. (a) Benito-Garagorri, D.; Kirchner, K., Acc. Chem. Res., 2008, 41, 201. (b) Peris, E.; Crabtree, R. H., Coord. Chem. Rev., 2004, 248, 2239. 3. (a) Hill, A. F.; McQueen, C. M. A. Organometallics, 2012, 31, 8051. (b) Hill, A. F.; McQueen, C. M. A. Organometallics, 2014, 33, 1977. 4. Dixon, L. S. H.; Hill, A. F.; Sinha, A.; Ward, J. S. Organometallics, 2014, 33, 653.
OL20 Stability of Tris-aryl Bi(V) Dicarboxylates & their Biological Activity Towards
Leishmania major
Yih Ching Ong,1 Victoria L. Blair,1 Lukasz Kedzierski,2 Kellie L. Tuck,1 Philip C. Andrews1 1School of Chemistry, Monash University, Clayton, Melbourne, Australia Email: [email protected] 2Walter and Eliza Institute of Medical Research, Parkville, Melbourne, Australia
Leishmaniasis, a group of diseases caused by the flesh-eating parasite Leishmania, have been treated for the past 70 years with organoantimonial(V) complexes.1,2 However, increasing resistance towards these drugs indicates a need to develop alternatives. Previous in vitro studies testing bismuth-based complexes have been conducted with promising results.3 Despite having a preference for the lower +3 oxidation state, Bi(V) complexes of the type
[BiAr3L2] have shown stability in both the solid state and in common solvents. We have synthesised a library of 4-6 Bi(V) complexes [BiAr3(O2CR)2] via a convenient one-pot reaction. They have shown good activity against Leishmania major (L. major) promastigotes while remaining non-toxic against human fibroblast cells (Figure 1). The stability of these Bi(V) complexes in culture media along with their biological activity towards L. major parasites and human fibroblast cells will be presented.
Figure 1. Activity of a representative Bi(V) complex against L. major parasites and human fibroblasts
References: 1. S.L. Croft, S. Sundar, A. H. Fairlamb, Clin. Microb. Review, 2006, 19, 111-126. 2. S. Sundar, D.K. More, M.K. Singh, V.P. Singh, S. Sharma, A. Makharia, P.C. Kumar and H.W. Murray, Clin. Infect. Dis., 2000, 31, 1104 -1107. 3. M.N. Rocha, P.M. Nogueira, C. Demicheli, L.G. de Oliveira, M.M. da Silva, F. Frézard, M.N. Melo and R.P. Soares, Bioinorg. Chem. Appl., 2013, DOI: 961783. 4. Y.C. Ong, V. L. Blair, L. Kedzierski, P. C. Andrews, Dalton Trans. 2014, 43, 12904-12916. 5. Y.C. Ong, V. L. Blair, L. Kedzierski, K. L. Tuck, P. C. Andrews, Dalton Trans. 2015, 44, 18215-18226. 6. V.V. Sharutin, I.V. Egorova, O.K. Sharutina, T.K. Ivanenko, M.A. Pushilin and A.V. Gerasimenko, Chem. Comp Simul., Butlerov Comm., 2002, 3, 59-62.
OL21 4-Acylpyrazolones: An Old Ligand Family with a New Coordination Mode
Karsten Gloe, Kerstin Gloe, Melanie Mohn, Jan J. Weigand Department of Chemistry and Food Chemistry, TU Dresden, 01062 Dresden/Germany [email protected]
4-Acylpyrazolones have received remarkable attention as versatile chelating agents in material chemistry, medicine, catalysis and solvent extraction [1,2]. Due to their simple synthesis a fine-tuning and modification of their physico-chemical properties are straightforward. For a long time we are interested in using acylpyrazolones as extractants [3]. Now we have synthesized different d- and f-block metal complexes with the ligand 4-propionyl- 3-methyl-1-phenyl-5-pyrazolone (HL). Whereas most of the complexes are characterized by the typical composition [MLn·(H2O)s] we have isolated two heterodinuclear complexes for Nd(III) and Yb(III) with the composition [ML4Na(H2O)2]. The different structures will be compared and discussed in detail.
[YbL4Na(H2O)2]
Acknowledgements: The authors thank the German Federal Ministry of Education and Research (BMBF – project 02NUK014A) and the European Research Council (ERC) (SynPhos project number 307616) for financial support.
References: 1. F. Marchetti, C. Pettinari, R. Pettinari, Coord. Chem. Rev. 2005, 249, 2909-2945. 2. F. Marchetti, R. Pettinari, C. Pettinari, Coord. Chem. Rev. 2015, 303, 1-31. 3. B. A. Uzoukwu, K. Gloe, H. Duddeck, Solvent Extr. Ion Exch. 1998, 16, 751-774.
OL22 Computational study of bridge variation of metal alkynyl complexes
M.S. Kodikara, R. Stranger, M.G. Humphrey Research School of Chemistry, Australian National University, Canberra, ACT 2601, Australia E-mail address: [email protected]
Density functional theory (DFT) and time dependent density functional theory (TD-DFT) studies were employed to probe linear and nonlinear optical properties of a set of novel D-π-A type organometallic complexes. Specifically, the effect of π-bridge variation (phenyl to naphthalenyl to anthracenyl) on the first hyperpolarizability was examined (Fig. 1.0). All of these systems have been synthesized and their first hyperpolarizability values determined using the hyper-Rayleigh scattering (HRS) technique at 1.064 µm. A characteristic intense charge transfer (CT) peak observed in the visible region for each complex was reproduced by TD-DFT calculations (Fig. 1.0). On the basis of the calculated linear optical data, the metal-to-ligand CT character of the main band decreases when the phenyl bridge is replaced with naphthalenyl and anthracenyl. Thus, π-bridge variation has a profound effect, resulting in a substantial decrease in both the experimental and calculated hyperpolarizability values from phenyl to anthracenyl.
Fig. 1.0 Calculated UV-Vis spectra of phenyl (red), naphthalenyl (blue), and anthracenyl (green) based model complexes (i.e. phenyl groups on the diphosphines were replaced with methyl fragments)
OL23 Recyclable Hybrid Rh and Ir Catalysts for C-X Bond Formation Reactions
(oral)
Chin Min Wong,1,2 D. Barney Walker,1,2 Alex H. Soeriyadi,1 J. Justin Gooding,1 Barbara A. Messerle.1,2 1School of Chemistry, University of New South Wales, Australia. E-mail: [email protected] 2Department of Chemistry and Biomolecular Sciences, Macquarie University, Australia
The development of hybrid catalysts paves the way as a practical route for taking advantage of the selectivity and reactivity of well-defined homogeneous complexes together with the convenience of heterogeneous systems.1 We are currently exploring the development of effective hybrid catalysts by anchoring highly efficient homogeneous catalysts onto a range of robust carbon materials as supports using strong C-C bonds. Recently, we developed a two step immobilization method of attaching homogeneous Rh(I) complexes (eg. 1, Figure 1) onto glassy carbon electrodes and the hybrid complexes catalyzed hydroamination reactions with an extremely high turnover number (>89,000).2 However, the relatively weak metal coordination of the bis(1-pyrazolyl) ligand led to a slight metal leaching after multiple cycles of the reaction.
Figure 1. Examples of hybrid Rh and Ir complexes and catalytic reactions catalyzed by the hybrid complexes.
In this work, we describe a more direct immobilization method for the development of a new series of Rh and Ir hybrid complexes containing a bidentate ligand that incorporates the more strongly coordinating N-heterocyclic carbene donor (eg. 2-3, Figure 1) and demonstrate the applicability of this methodology on a variety of carbon surfaces; ie. glassy carbon electrode, carbon black and graphene. Using this new series of Rh catalysts, we can promote the hydrosilylation reaction with improved activity and increased stability over multiple reaction cycles. We further describe some preliminary work on using the hybrid complexes for other C-X bond formation reactions such as C-N bond formation reactions via hydrogen borrowing.
References: 1. Heterogenized Homogeneous Catalysts for Fine Chemicals Production, ed. P. Barbaro, F. Liguori, Springer: Dordrecht, The Netherlands, 2010. 2. (a) A. A. Tregubov, K. Q. Vuong, E. Luais, J. J. Gooding, B. A. Messerle, J. Am. Chem. Soc. 2013, 135, 16429. (b) A. A. Tregubov, D. B. Walker, K. Q. Vuong, J. J. Gooding, B. A. Messerle, Dalton Trans. 2015, 44, 7917.
OL24 Ruthenium Alkynyl Cruciforms and the Solubility Conundrum
Mahbod Morshedi, Ellen F. Phiddian, Marie P. Cifuentes, Mark G. Humphrey
Research School of Chemistry, Australian National University, ACT 2601, Australia Email: [email protected]
The effects of symmetry on nonlinear optical (NLO) responses can give new insights into the mechanisms involved in optimization of NLO properties.[1]. Conjugated π-extended systems based on phenyleneethynylene scaffolding are of significant interest, since tweaking basic structural motifs can lead to collective understanding of third-order NLO responses.[2] Although organic phenylethynyl-based cruciforms are well established, organometallic derivatives with such symmetry are less known. Herein, the synthesis of a series of donor-acceptor substituted 1,2,4,5-tetrakis(phenylethynyl)benzenes is presented. The insolubility of some derivatives is also described.
Acknowledgements: We thank the Australian Research Council for funding and support.
References: [1] a) C. Bosshard, R. Spreiter, P. Günter, R. R. Trkwinski, M. Schreiber, F. Diederich, Adv. Mater. 1996, 8, 231-234; b) K. Ohta, S. Yamada, K. Kamada, A. D. Slepkov, F. A. Hegmann, R. R. Tykwinski, L. D. Shirtcliff, M. M. Haley, P. Sałek, F. Gel’mukhanov, H. Ågren, J. Phys. Chem. A 2011, 115, 105-117; c) X.-B. Zhang, J.-K. Feng, A.-M. Ren, C.-C. Sun, Opt. Mater. 2007, 29, 955-962. [2] a) J. A. Marsden, J. J. Miller, L. D. Shirtcliff, M. M. Haley, J. Am. Chem. Soc. 2005, 127, 2464-2476; b) E. L. Spitler, J. M. Monson, M. M. Haley, J. Org. Chem. 2008, 73, 2211-2223.
OL25 Investigating the Anti-Cancer Potential of Rh-Pentamethylcyclopentadiene Complexes
J. Markham,1 J. Liang,1 A. Levina,1 P. A. Lay,1 1School of Chemistry, The University of Sydney, NSW, 2006, Australia [email protected]
Since the 1965 discovery of the Pt(II)-based anti-cancer drug cisplatin, there has been growing interest in the development of new metal-based anti-cancer agents.1 This has led to the development of drugs incorporating metal centres near to Pt in the periodic table, in anticipation that they can imitate and improve upon the function of cisplatin. Recent success of hexa-coordinated Ru(III) drugs (NAMI-A and KP1019)2, and Ru(II) drugs that incorporate η6-arene ligands (RAPTA-C and RM175)2 have led to the consideration of Rh(III)-based chemotherapeutic agents.3 The incorporation of an η5-pentamethylcyclopmentadienyl (*Cp) ligand has helped in overcoming the characteristic substitutional inertness of Rh(III), a property that has compromised its perceived potential as an anti-cancer agent.
A range of Rh(III)-*Cp complexes were synthesised and characterised and their anti-cancer properties were investigated through a series of biological assays using the A549 cancer cell line. While many Rh(III)-*Cp had no anti-cancer effects in vitro, a new complex, [*CpRhCl(curcumin)] with bioactive curcumin was investigated. A major barrier to curcumin’s use as a chemotherapeutic = agent is its low bioavailability and poor water solubility.4 Exploiting the established biological inactivity of Rh(III)-*Cp moiety this unit was used to delivery curcumin.
X-ray absorption spectroscopy speciation studies were also performed at the Australian Synchrotron to investigate the reactivity and speciation of the new Rh-Curcumin complex and other Rh-*Cp complexes under biologically relevant conditions.
Acknowledgements: We are grateful from support from the Australian Synchrotron including beamline scientists, Dr Peter Kappen, Chris Glover and Bernt Johannessen, the Australian Research Council, The Bosch Institute and the Sydney University Microscopy and Microanalysis Facility.
References:
1. V. T. DeVita and E. Chu, Cancer Res. 2008, 68, 8643. 2. F. Trudu, F. Amato, P. Vanhara, T. Pivetta, E. M. Pena-Mendez, J. Havel, J. Appl. Biomed. 2015, 13, 79. 3. Y. Geldmacher, M. Oleszak, W. S. Sheldrick, Inorg. Chim. Acta 2012, 393, 84. 4. N. G. Vallianou, A. Evangelopoulos, N. Schizas, C. Kazazis, Anticancer Res. 2015, 35, 645.
OL26 Synthesis of Lanthanoid-Aluminium Bimetallic Complexes
Md Elius Hossain1, Jun Wang1 and Peter Junk1
1College of Science, Technology & Engineering, James Cook University, Townsville, Qld 4811, Australia [email protected]
Bimetallic (Ln/Al) complexes have found major applications such as catalytic activity in industrial polymerization. The research in the halide complexes of this category has been focused on chloride complexes1,2 and the relevant iodides are among rare species. The work presented herein includes the synthesis and characterisation of bimetallic complexes of aluminium and lanthanoid iodides, [Ln(AlI4)2(toluene)]n (Ln = Yb, Sm and Eu) and [Ln(AlI4)3(toluene)]n (Ln = La and Nd). A serial of new complexes have been synthesized through the reactions between aluminum iodide and lanthanoid iodides in toluene at 110°C for two hours.
H3C I I # toluene I Yb Al AlI3 + YbI 2 I I I Al I
I I References: 1. H. Liang, Q. Shen, J. Guan and Y. Lin, Journal of Organometallic Chemistry, 1994, 474, 113-116. 2. H. Liang, Q. Shen, S. Jin and Y. Lin, J. Chem. Soc., Chem. Comm., 1992, 480-481.
OL27 Metallations of Imines: Addition, Deprotonation and Cyclisation
E. Border,1 P. Andrews1 1Monash University, Wellington Road, Clayton, Melbourne, 3800 [email protected]
When an imine is reacted with an organolithium source such as nBuLi, the addition across the carbon nitrogen double bond can occur in the same manner as a 1,2 addition to a carbonyl species.1 These 1,2 additions of organometallics have also been observed with Grignard reagents and other organometallic reagents involving zinc, titanium, and aluminium, commonly being utilised for the asymmetric synthesis of amines.2, 3 However little attention has been focused on their general structure and reactivity with the heavier alkali metals, where it is expected that deprotonations will occur in preference to 1,2 additions. Here we present the reactions of N-[(4- methoxyphenyl)methylene]-benzenamine 1 with three different alkali metal sources; NaHMDS, nBuNa and LDA, isolating three new and very different complexes. A 1-aza-allyl species {[PhN…CPh(4- n OMe)]Na}2{[PhN=CHPh(4-OMe)]}2 2, an unprecedented 1,2 addition of BuNa {[PhNCH(C4H9)Ph(4-
OMe)]Na.THF}2 3 and a cyclisation reaction {[5-(OMe)3-Ph(4-OMe)2-(Ph)isoindol-1-ine](Ph)NLi.THF} 4 respectively, which have been characterised by X-ray crystallography and solution studies.
O O O Na NaHMDS nBuNa Na N N N
2 1 3 Deprotonation LDA 1,2 addition
Li N O
N
4 O
Cyclisation
References: 1. S. Suga, M. Kitamura Comprehensive Chirality, Elsevier, Amsterdam, 2012, 328 2. D. Enders and U. Reinhold, Tetrahedron: Asymmetry, 1997, 8, 1895. 3. R. Bloch, Chem. Rev., 1998, 98, 1407.
OL28 Mechanistic Studies of Catalytically Relevant N-Heterocyclic Carbene
Transformations
Tanita S. Wierenga,1 Michael G. Gardiner,1 Curtis C. Ho,1 Alireza Ariafard1,2 1 School of Physical Sciences – Chemistry, University of Tasmania, Private Bag 75, Hobart, Tas 7001 [email protected] 2 Department of Chemistry, Faculty of Science, Central Tehran Branch, Islamic Azad University, Shahrak Gharb, Tehran, Iran
A large volume of research has been dedicated to the preparation of catalytically relevant chelating methylene- linked bis(N-Heterocyclic Carbene) (bisNHC) palladium complexes. NHCs have many advantages to their traditional phosphine analogues and bisNHCs have been used in various applications including C-H activation1 and CO/alkene copolymerisation2. Our group has been interested in palladium bisNHCs using longer linker lengths with bulky N-substituents as previous studies with bis(phosphine) complexes showed that longer linker increases the catalytic activity.3
However, during the synthesis of extended linker complexes with the N-Mesityl substituent an unexpected ligand rearrangement occurred. Along with the expected chelate, a second complex with an additional C-C bond between the two imidazole based rings was formed. Given the extensive usage of this ligand class in catalysis further studies were performed.
Scheme 1 DFT investigations revealed two energetically competing pathways due to the increase in steric hindrance (Scheme 1). The DFT mechanism will be supported by synthetic studies probing the effect of steric bulk by synthesising similar steric bulk substituents as well as synthesising various proposed intermediates including mixed normal(NHC)-abnormal(NHC) complexes.
References: 1. D. Munz, T. Strassner, Angew. Chem. Int. Ed. 2014, 53, 2485. 2. S. S. Subramanium, L. M. Slaughter, Dalton Trans. 2009, 6930. 3. E. Drent, J. A. M. v. Broekhoven, M. J. Doyle, J. Organomet. Chem. 1991, 417, 235.
OL29 An Exploration of Primary Phosphine and Phosphido Complexes
Yong-Shen Han,1 Anthony F. Hill 1Research School of Chemistry, Australian National University, Acton, Australia 2601 [email protected]
3-coordinate phosphorus ligands LnM-PR2 may display dichotomous behaviour depending on the effective atomic number of the metal fragment (LnM). When the PR2 group is bound to 17 valence electron (17VE) LnM, it provides 1 1VE (X-ligand) with pyramidal, nucleophilic phosphorus, e.g., Cp(CO)2Fe-PR2. In contrast, when bound to a
15VE MLn, the phosphorus may be trigonal and electrophilic serving as a 3VE XL-ligand. For high d-occupancy late T-metals, a conflict arises between the potentially π-dative lone pair on phosphorus and occupied metal dπ orbitals so as to destabilise saturated complexes. Chemical implications include remarkable basicity and the 2 inferred operation of SN1cB ligand substitution processes, as observed in analogous amido complexes.
We describe the synthesis of late T-metal complexes of primary phosphines with a view to exploring their deprotonation to afford highly basic and nucleophilic phosphido complexes. These include complexes of the form
[RuCl(PH2Cy)(PPh3)(Tp)] and [Ru(PH2Cy)(L)(L’)(Tp)]PF6 (L, L’ = 1,1’-bis(diphenylphosphino)ferrocene; L =
PPh3, L’ = PH2Cy; Tp = hydrotris(pyrazolyl)borate).
Tp Tp
PH2Cy Ru Ru Ph3P Cl MeOH Ph3P PH2Cy Ph3P CyH2P
PH2Cy C7H8
Tp
Ru Ph3P Cl
CyH2P
Acknowledgements: Dr Anthony C. Willis and Dr Jas S. Ward are thanked for assistance with crystallography.
References: 1. L. D. Hutchins, E. N. Duesler & R. T. Paine, Organometallics 1982, 1, 1254. 2. a) K.G. Caulton, New J. Chem. 1994, 18, 25. b) M. A. Dewey, D. A. Knight, A. Arif & J. A. Gladysz, Chem. Ber. 1992, 125, 815. c) D. Conner, K. N. Jayaprakash, T. B. Gunnoe & P. D. Boyle, Inorg. Chem. 2002, 41, 3042. d) D. Rais & R. G. Bergman, Chem. Eur. J. 2004, 10, 3970.
OL30 Transition-metal mediated reactions of strained ring sytems
Christopher Hyland,1 JieXiang Yin, Yi Sing Gee and Daniel Rivinoja 1 School of Chemistry, University of Wollongong. [email protected]
Research in our group has focused on harnessing the reactivity of activated three-membered systems, such as 2- vinyl/aryl-N-Ts-azirdines and vinylcyclopropane-1,1-dicarboxylates. For example, a Z-selective palladium(II)- catalysed addition of arylboronic acids to 2-vinyl-N-Ts-aziridines has been developed. This reaction proceeds via a redox-neutral insertion/ring-opening process to provide (Z)-allylsulfonamides stereoselectively.1 Further, palladium(II)-salts, in combination with benzoquinone, have been shown to function as an effective Lewis-acid-catalyst system for the C3-substitution of indoles with 2-aryl-N-Ts-aziridines, yielding precursors to biologically important pyrrolindoles. Finally, in an exciting development, a highly efficient ring-opening reaction of vinylcyclopropane-1,1-dicarboxylate by boronic acids in neat water will be presented. This reaction is catalysed by in-situ generated palladium(0) nanoparticles that are formed from Pd(OAc)2 under ligand-less conditions. Importantly, we were able to switch between linear or branched products by judicious choice of the starting vinylcyclopropane-1,1-dicarboxylate.2
R
Ar N Versatile substrates R NHTs Pd(OAc) (10 mol%) PdCl2(MeCN)2 (10 mol%) 2 X BQ (30 mol%) Phen (12 mol%) TsHN Ar N R Arylboronic acids CHCl3, r.t X= NTs R= Vinyl o AgSbF6 (12 mol%), DCE, 70 C 10 examples 25-94% yield X= NTs R= Aryl X= C(CO2Et)2 or Unusual Z selectivity 15 examples 57-77% yield X= NTs Precursors to pyrrolindoles
Pd(OAc)2 (1 mol%) X= C(CO2Et)2 H2O, r.t Aryl/Alkenyl boronic acids
CO Et 2 2 Ar CO2Et
Ar CO2Et 1 or Ar CO2Et R= vinyl R= aryl-substituted vinyl Linear selectivity Branched selectivty 13 examples 23-96% yield 13 examples 38-96% yield
Acknowledgements: The University of Wollongong is thanked for generous funding.
1 J. X. Yin, T. Mekelburg, C. Hyland, Org. Biomol. Chem., 2014, 12, 9113-9115. 2 J. X. Yin, C. J. T. Hyland, J. Org. Chem., 2015, 80, 6529–6536.
POSTER ABSTRACTSPOSTER
P1 Novel and simple method to synthesize silver pyrazolates
Zhifang Guo, Glen B. Deacon*, Andreas Stasch, Peter C. Junk
School of Chemistry, Monash University, Clayton 3800 VIC, Australia
Silver pyrazolates with high yields were successfully synthesized by stirring silver oxide and pyrazoles either in pyridine or acetonitrile, which is more convenient than reported methods. [1-4] The reaction is easily monitored by disappearance of black silver oxide, and the reagents are easier to handle compared [3] t with using water sensitive sodium pyrazolates. [Ag3(Ph2pz)3]2, [Ag( Bu2pz)]4, and [Ag(Phtpz)3] have been synthesized by silver oxide with R2pzH, 3,5-diphenylpyrazole (Ph2pzH), 3,5-ditertbutylpyrazole t ( Bu2pzH), and 3-phenyl-5-(2-thienyl)pyrazole (PhtpzH) with the yields of 87%, 84%, and 80% respectively. The first two structures were verified by unit cell data in agreement with reports [3, 4] and the third one is a new structure, but has a twinning problem, still to be overcome.
py or CH3CN 3Ag2O + 6R2pzH [Ag3(R2pz)3]2 + 3H2O stir 20 min
References: 1. S. Krackl, S. Inoue, M. Driess, S. Enthaler, Eur. J. Inorg. Chem., 2011, 2103. 2. G.Yang, P. Baran, A. Martinez, R. Raptis, Cryst. Growth Des., 2013, 13, 264. 3. A. Mohamed, L. Pe ́rez, J. Fackler Jr, Inorg. Chim. Acta., 2005, 358, 1657. 4. G.Yang, R. Raptis, Inorg. Chim. Acta., 2007, 360, 2503.
P2 Hybrid Stacked/Laddered Organolithium Aggregates: A Structural Hypothesis for
Superbase Activity
S. R. Harris,1 M. G. Gardiner1, N. L. Kilah1
1School of Physical Sciences – Chemistry, University of Tasmania, Private Bag 75, Hobart, Tas 7001 [email protected]
It is well established that "laddering" and "stacking" aggregations are the two main tendencies for organolithium compounds[1]. However in the more complex area of mixed anion and mixed metal systems, it is much less clear. It was discovered in the 1960’s that the reactivity of simple alkyllithium complexes can be greatly increased by the addition of heavier alkali metal alkoxides.[2] These mixed systems were dubbed "superbases". Later generation superbases had unique proton abstraction selectivities and hinted at the promise of tailored bases for any synthetic requirement. However, despite being known for over 40 years, very little is still known about the active component or mechanism of these complex systems. Previous work in this area was performed in systematically studying homo-metallic tethered mixed anion systems, as a simplification of the more complex first generation superbases with the aim to gain further understanding of the underlying reasons for superbase reactivity. In the course of these studies, a range of unusual structures were uncovered, and a new superbase class with highly specific reactivity towards C-O cleavage of chelating aprotic Lewis bases. Remarkably, this very high deprotonation ability exists for a lithium amide/alkoxide system (which ort not to possess deprotonation strength even comparable with lithium alkyls). Through investigating an analogous ligand set, we have uncovered a number of novel complex structures which show hybridisation of stacked and ladder aggregation. These have been shown to vary greatly in structure with minimal change to the mixed anionic ligand. Through these we seek to ascertain what effect changes to the aggregation structure will have on the chemical properties of the resultant lithium complex and to thus better understand the mechanisms behind the superbasic reactivities that are observed.
References: [1] R. E. Mulvey, Chem. Soc. Rev., 1991, 20, 167. K. Gregory, P. v. R. Schleyer, R. Snaith, Adv. Inorg. Chem., 1991, 37, 47. [2] L. Lochmann, J. Pospisil, D. Lim, Tetrahedron Lett., 1966, 257. M. Schlosser, J. Organomet. Chem., 1967, 8, 9.
III P3 EPR spectroscopic characterisation and fate of a monomeric Pt species produced via
electrochemical oxidation of the anticancer compound trans-[PtII{(p-
BrC6F4)NCH2CH2NEt2}Cl(py)]
Ruchika Ojha1, Alan M. Bond1, Glen B. Deacon1, Stephen P. Best2, Peter C. Junk3 1Monash University, School of Chemistry, Clayton 3800 VIC, Australia [email protected] 2 University of Melbourne, School of Chemistry, Parkville 3010 VIC, Australia 3College of Science, Technology & Engineering, James Cook University, Townsville, Qld, 4811, Australia
Recently we established that highly non-coordinating media provide conditions conducive to formation of monomeric PtIII derivatives in the electrochemical oxidation of the anticancer compound trans-[PtII{(p- 1 II BrC6F4)NCH2CH2NEt2}Cl(py)] under short voltammetric time scales. Almost quantitative transformation of Pt to PtIII occurred under short time scale voltammetric conditions. Small concentrations of the paramagnetic monomeric PtIII species remaining after longer timescale bulk electrolysis experiments were identified by EPR spectroscopy. We now report the characterization of some of the products (PtII organoeneamineamides) formed by chemical oxidation of the platinum anticancer compound and by exhaustive bulk electrolysis. Relationships between PtIII intermediates and PtII organoeneamineamides isolated in this study are considered. Interestingly, some but not all products obtained from chemical oxidation (see Figure 1) are the same as those derived from electrochemical oxidation.
Figure 1. X-ray crystal structures of substituted and non-substituted organoenamineamides obtained after chemical II oxidation of trans-[Pt {(p-BrC6F4)NCH2CH2NEt2}Cl(py)] with hydrogen peroxide.
References: 1. R. Ojha, A Nafady, M. J. Shiddiky, D. Mason, J. F. Boas, A. A. J. Torriero, A. M. Bond, G. B. Deacon, P. C. Junk, ChemElectroChem. 2015, 2, 1048.
P4 Synthesis of pyrrole based N-heterocyclic chalcogenides and 8,8´-diquinoline
dichalogenides
Rajesh Deka,1 Harkesh B. Singh,1* Glen B. Deacon,2*, David Turner 2* and Peter C. Junk3*
1 Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India; 2School of Chemistry, Monash University, Clayton 3800 VIC, Australia; 3 College of Science, Technology & Engineering, James Cook University, Townsville City QLD 4811, Australia.
The reaction of lithium complex of 2,5-[bis-(dimethylamino)methyl] pyrrole, Li[NC4H2(CH2NMe2)2-2,5] with phenylselenyl bromide and phenyltellurenyl bromide leads to the formation of pyrrole-chalcogen complexes. Here chalcogens (Se/Te) are in +2 oxidation state and share a pure covalent bond with N of pyrrole. The syntheses of these compounds are confirmed by common spectroscopic techniques. 8,8´-diquinoline dichalcogenide, believed to be ideal ligands to react with lanthanides were synthesized by the reaction of 8-bromoquinoline with in-situ generated Na2E2 (E = Se, Te).
N N N PhEBr, THF n- BuLi, Hexane N E N H NLi 5 h, -78 °C 1 h, -78 °C N N N E=Se/Te
Br N N Na2E2, DMF E E o 120 C N E = Se/Te
P5 Synthesis and structure of Rare-Earth
3, 5-Dimethylpyrazolate complexes
N. Eslamirad, 1 P. C. Junk1, J. Wang1 1 College of Science, Technology & Engineering, Building 21, James Cook University, Townsville, Qld, 4811, Australia. [email protected]
Rare earths are under-utilized metals and an understanding of their chemical properties in their compounds is paramount for future applications. Since coordination behaviour of pyrazoles and pyrazolate ions are widely versatile towards a great range of metals such as d-block, f-block as well as main group elements, they attract interest as ligands for preparing compounds [1, 2]. We now report the synthesis of new rare-earth
3, 5- dimethylpyrazolate (Me2pz) complexes through the redox transmetalation/protolysis (RTP) with scandium, [3] Hg(C6F5)2 and Me2pzH . Despite the same method for two reactions, two completely different structures were observed (Fig. 1a & 1b). According to Fig. 1a, although grease was not the initial reagent there is silicon in the structure. Moreover, it can be observed from fig. 1b through another same RTP reaction the synthesized compound is trinuclear.
(a) (b)
Figure 1. Crystal structure of a) [Sc2(Me2Pz)6(SiOMe2)2] b) [Sc3(Me2pzH)2(Me2pz)7O]
Acknowledgements: We thank Australian Research Council for support. Aspects of this research were undertaken on the MX1 beamline at the Australian Synchrotron, Victoria, Australia.
References: 1. G. B. Deacon, P. C. Junk, A. Urbatsch, Dalton Trans, 2011, 40, 1601-1609. 2. M. A. Halcrow, Dalton Trans., 2009, 2059-2073. 3. G. B. Deacon, R. Harika, P. C. Junk, Eur. J. Inorg. Chem., 2014, 2412-2419.
P6 Anion Rearrangements in Alkali Metal Complexes of (S)-N-(α- Methylbenzyl)methallylamide
Matt Flynn,1 Victoria Blair,1 Rachel Stott,1 Phil Andrews1
1School of Chemistry, Monash University. Email: [email protected]
Derivatives of (R/S)-α-methylbenzylamine have been used as chiral reagents in conjugate additions with α,β- unsaturated esters, the products of which can then be reacted further to produce β-amino acids in high enantiomeric purity1. (R/S)-N-(α-methylbenzyl)allylamine has proven to be one of the more valuable derivatives, as the allyl and methylbenzyl groups are easily removed to furnish the β-amino acid. Alternatively, the allyl group has been found to be able to react further, for example in a tandem addition/cyclisation reaction to produce pyrrolidines with good diastereoselectivity2. Due to this synthetic utility, it is of interest to investigate the structural properties of the metallated intermediates in these reactions, given the known relationship between structure and reactivity. In the course of these investigations, the Andrews group has found that alkali metal complexes of (S)-N-(α- methylbenzyl)allylamide can undergo facile anion rearrangements at room temperature, to the aza-allyl or aza- enolate forms, depending on the metal and coordinating Lewis donor used3,4.
N H
nBuM Hexane -78 °C
N N N M.L M.L M.L allyl-amide aza-allyl aza-enolate M = Li M = Li M = Li, Na L = HMPA L = TMEDA L = PMDETA
Due to the obvious impact this will have on the outcome of reactions, the cause of these rearrangements is of interest. Recent research has investigated the analogous complexes of (S)-N-(α-methylbenzyl)methallylamine, to help elucidate the driving forces of these rearrangements. The results of this investigation will be presented.
References: 1. S. G. Davies, A. D. Smith, P. D. Price, Tetrahedron Asymmetry, 2005, 16, 2833-2891 2. F. Kafka, M. Holan, D. Hidasová, R. Pohl, I. Císařová, B. Klepetářová, U. Jahn, Angew. Chem. Int. Ed., 2014, 53, 9944-9948 3. P. C. Andrews, M. Koutsaplis, E. G. Robertson, Organometallics, 2009, 28, 1697-1704 4. P. C. Andrews, S. M. Calleja, M. Maguire, P. J. Nichols, Eur. J. Inorg. Chem., 2002, 2002, 1583-1587
P7 Novel Structures of Naphthyl Lithium Amides
Greer, J.1 Andrews, P.2 Blair, V.2 [email protected] [email protected]
Lithium metal amides are common tools used in synthetic chemistry. These reagents have a wide variety of applications owing to their capacity to deprotonate weakly acidic species. Anion rearrangements of these species causing structural changes have frequently been observed depending on the chosen metal and combination of lewis donors used. To further expand on the knowledge of these rearrangements a series of lithium naphthylamide species were synthesized and characterised by 1H, 13C, and 7Li NMR spectroscopy, and single crystal x-ray diffraction.
Synthesis and structural characterization of mono-, di, and trilithiated naphtylamide complexes have been determined to be the dimers [Li{(1-naph)(CH2CH=CH2)N}·Et2O]2, [Li{(1,8-naph)(CH2CH=CH2)NLi·(µ- t THF)}·THF], and (R/S)-[Li{(1,8-naph)(CH2( Bu)CHCH2Li·THF)NLi·THF}].
Donor studies were conducted which identified two novel structures being the monomer, [Li{(1- naph)(CH2CH=CH2)N}·PMDTA] and complex, [Li·(TMEDA)2][Li{N(1-naph)(CH2CH=CH2)}2], a contact ion pair showing the first structurally characterised amido lithate motif. The TMEDA structure was also found to gradually undergo a 1,3-sigmatropic rearrangement in solution.
t Figure 1: ASU of (R)-[Li{(1,8-naph)(CH2( Bu)CHCH2Li·THF)NLi·THF}].
P8 Bioorganometallic Complexes as Anti-Cancer and Anti-Tuberculosis Agents:
Synthesis, Characterization and Biological Evaluation.
C. Quintana,1 R. Arancibia,2 A. H. Klahn,3 M. Fuentealba,3 V. Artigas, 3 L. 4 Kremer. 1Research School of Chemistry Australian National University, Canberra ACT 2601, Australia, [email protected] 2Departamento de Química Analítica e Inorgánica, Universidad de Concepción, Chile.21 3Instituto de Química, Pontificia Universidad Católica de Valparaíso, Chile. 4Unité de Recherche Dynamique des Intéractions Membranaires Normales et Pathologiques, Université Montpellier, Montpellier, France.
During the last few decades the Organometallic Chemistry group at the Pontificia Universidad Católica de Valparaíso, Chile, has focused on the development of novel organometallic pharmacophores with potential applications in the treatment of world-wide high priority diseases such as tuberculosis and cancer1. The rational design of the compounds has involved the coupling of electro-donating (D) and electron-accepting (A) organometallic complexes such as ferrocene (D) and cyrhetrene (A) to well-known organic bioactive building blocks including 1,3,4-thiadiazoles, sulfonamides and sulfonohydrazides2, to study their electronic properties and relate this to their biological activity. I will summarize some of the most remarkable biological activity results.
R
S NH
N N Re OC CO CO R'
H N N S
Fe
R'' H N S
Acknowledgements: Thanks to CONICYT and the Australian National University for funding. References: 1. World Health Organization: http://www.who.int/gho/malaria/en/
2. V. Alterio, A. Di Fiore, K. D’Ambrosio, C. T. Supuran, G. De Simone, Chem. Rev. 122 (2012) 442
P9 “Normalised” abnormal carbene palladium complexes
Catriona R. Vanston,1 Thomas. P. Nicholls,1 Michael. G. Gardiner1 1 School of Physical Sciences (Chemistry), Private Bag 75, University of Tasmania, Hobart, TAS, 7001.
Abnormal carbenes (aNHCs) are notable for their mesoionic character; unlike normal carbenes (nNHCs) it is not possible to draw a reasonable neutral resonance form. The increased charge separation results in a stronger anionic character of the carbene, which in turn enhances the donor ability. Abnormal carbenes are therefore of great interest for their significant electronic effects relative to nNHC species, and have interesting potential for catalytic applications.1 We have prepared several complexes using a biaryl ligand system which, with a coplanar ring arrangement allows for pi bond conjugation and for a charge-balanced resonance form to be available. These compounds are novel in that they could be described as “normalised” abnormal carbene complexes.
These compounds were formed by oxidative addition of a brominated precursor to low-valent palladium with various ancillary ligands as shown in Figure 1 below.
N n+ N - 2[PF6] X L 1. Pd(dba)2 Pd Br 2. L pyridine L 75 oC - N N N N n[PF6] 2 hrs
X= Br, I L=PPh3, bipy, X/py
Figure 1. Preparation of “normalised” abnormal carbene complexes.
We have used NMR spectroscopy and X-ray diffraction to structurally characterise these complexes and examine the degree of ligand conjugation.
References: 1. Sau, S. C., Santra, S., Sen, T. K., Mandal, S. K. and Koley, D., Chem. Commun. 2012, 48, 555.
P10 Synthesis and characterisation of novel di- and tri-bismuth(III) aromatic compounds and evaluation of their anti-Leishmanial activity
K. J. Burke,1 V. L. Blair, and P. C. Andrews 1School of Chemistry, Monash University, Melbourne, VIC, 3800, email: [email protected]
Pentavalent antimonals have been used successfully to treat Leishmania. However their undesirable side effects and administration method have led to non-compliance resulting in treatment failures and even drug resistance in some areas. This has lead to bismuth(III) compounds being explored for an alternative active species, due to their apparent low toxicity and periodic relationship with antimony. Only one di-bismuth compound has been evaluated for anti-Leishmanial activity,1 while other previously reported and evaluated compounds contained only one bismuth atom per molecule.2-6 It is therefore of interest to further explore the anti-Leishmanial potential of di- and tri-bismuth substituted molecules, such as compounds 1-3 and their derivatives 4-6 (Fig 1.).
BiL BiPh2 BiPh2 BiLn n
LH BiPh2 BiLn 2 5 BiPh2 BiLn
1 BiPh2 4 BiLn
L = select thiocarboxylates, thiolates, and carboxylic acids
Ph2Bi BiPh2 LnBi BiLn 3 6
Figure 1. Precursor poly-bismuth aromatics 1-3 and their derivatives 4-6.
The synthesis and characterisation of these di- and tri-bismuth(III) aromatic compounds will be presented, along with some possible ligand classes and reaction schemes that may be used to form a new Bi(III) center.
References: 1. M. N Rocha, P. M. Nogueria, C. Demicheli, L. G. Oliveira, M. M. Silva, F. Frezard, M. N. Melo and R. P. Soares, Bioinorg. Chem. Appl., 2013, 2013, 961783. 2. P. C. Andrews, R. Frank, P. C. Junk, L. Kedzierski, I. Kumar, and J. G. MacLellan, J. Inorg. Biochem., 2011, 105, 454. 3. Y. C. Ong, V. L. Blair, K. Lukasz and P. C. Andrews, Dalton Trans., 2014, 33, 12904. 4. P. C. Andrews, V. L. Blair, R. L Ferrero, P. C. Junk, L. Kedzierski, and R. M. Peiris, Dalton Trans., 2014, 43, 1279. 5. P. C. Andrews, P. C Junk, L. Kedzierski, and P. M. Peiris, Aust. J. Chem., 2013, 66, 1297. 6. A. Luqman, V. L. Blair, R. Brammananth, P. K. Crellin, R. L. Coppel. L. Kedzierski, and P. C. Andrews, Eur. J. Inorg. Chem., 2015, 4, 725.
P11 Selenium-interrupted carbochain bridged bimetallics
Richard Manzano,1 Timothy Evers,1 Anthony Hill,1 C. Jas Ward1 1Research school of Chemistry, Australian National University, Canberra, Australian Capital Territory, Australia, [email protected]
The chemistry of bimetallics spanned by a linear chain of carbon atoms, LnMCxMLn, (dimetallapolycarbyls) has been well investigated and of interest both fundamentally, and because of the applications that might result from electronic communication between metal termini.1 If, in the context of molecular circuitry, such complexes can be described as molecular wires, then the question of molecular transistors arises. We suggest that the inclusion of main group element within the dimetallapolycarbyl chains provides a conceptual point of connection – a molecular transition gate.
We have therefore then begun the synthesis of dimetallapolycarbyls complexes with the inclusion of main group elements within polycarbyl chains. For groups 15 and 16 elements, these would carry a lone pair of electrons that are available for coordination to Lewis acids (including further transition metals). On the other hand, group 13 elements with a vacant p-orbital could act as site of coordination for Lewis bases. Either case would be susceptible to redox-induced geometrical changes, consistent with simple VESPR arguments.
This poster discusses the investigation of including selenium within dimetallapolycarbyls either within the carbon chain, or as the point of connection with the transition metal termini. Starting with precursors WTp*(CO)2C≡Br and WTp*(CO)2≡CC≡CSiMe3 (Tp* = tris(3,5-dimethylpyrazolyl)borate) we have successfully synthesized multimetallapolycarbyls (WTp*(CO)2CSeCC)2Hg and WTp*(CO)2CCCSeRuCp(PPh3)2 respectively via a number of subsequent reactions.
Acknowledgements: Research School of Chemistry
References: 1. Bruce, M. I.; Low, P. J. Adv. Organomet. Chem. 2004, 50, 179.
P12 Divalent Lanthanoid Complexes of Bulky Amide Ligands
Caspar de Bruin-Dickason, Glen Deacon, Cameron Jones* School of Chemistry, Monash University. [email protected]
Monodentate amide ligands are a mainstay of organometallic lanthanoid chemistry,[1] however sterically bulky amides have not been thoroughly investigated as ligands for these metals. These ligands have recently been applied with great success to stabilisation of unusual main group and transition metal complexes. In this work, several novel low-coordinate amidolanthanoid and alkaline earth complexes have been synthesised using bulky, monodentate amido- ligands.
These complexes (Figure 1) will serve as templates towards the synthesis of low oxidation state lanthanoid complexes for lanthanoids not commonly found in the +2 oxidation state (e.g. TmII, DyII and NdII), and will be investigated as catalysts for organic transformations, and the activation of small molecules.
Figure 1: Crystal structures of two bulky ytterbium complexes synthesized as part of this work. Left † [Yb{N(Ar )(SiMe3)}2], right [Yb{N(Dip)(Mes)}2(thf)]
References: 1. M. Lappert, A. Protchenko, P. Power, A. Seeber, Metal amide chemistry, John Wiley & Sons, 2008.
P13 Diastereoselective and Regioselective Allenylation of Chiral Amino Aldehydes
Farzad Zamani, Stephen G. Pyne, Christopher J. T. Hyland
School of Chemistry, University of Wollongong, NSW, Australia
Chiral allenes containing heteroatoms play a particularly significant role in organic synthesis, since they can be converted under mild conditions into biologically active heterocycles via cyclization reactions.1 Although many methods to prepare allenes exist, highly functionalized allenes containing both pendant oxygen and nitrogen functionalities are not readily synthetically accessible. Such compounds are particularly valuable substrates as the pendant heteroatoms allow them to undergo metal-catalyzed intramolecular cyclizations to heterocycles with a pendant heteroatom adjoined to a stereogenic centre. Utilising the allenylboronic pinacol ester and diethylzinc system, which has been reported for preparation of allenyl alcohols,2 a range of allenylamino alcohols has been prepared in high yields and with excellent diastereoselectivity. These allenyl products were subjected to gold- catalyzed ring-closure reaction and deprotection to obtain dihydrofurans in excellent yield. The reaction optimization, substrate scope and product manipulation will be presented.
OH
R CHO R ∗ o ∗ Et2Zn (10 mol%) ∗ 1) AuPPh3NTF2 (10 mol%), DCE, 60 C, 8 h ∗ + ∗ R 2) TMSCl, MeOH, r.t, overnight O NBnBoc Bpin toluene, 0 oC, 18 h NBnBoc NHBn 8 examples 71-96% yield up to 100% diastereoselectivity up to >98% regioselectivity to allene
Acknowledgements: University of Wollongong is highly appreciated for UPA and IPTA scholarships, as well as providing the corresponding facilities for this work.
References:
1. D. Campolo, S. Gastaldi, C. Roussel, M. P. Bertrand, M. Nechab, Chem. Soc. Rev. 2013, 42, 8434.
2. D. R. Fandrick, J. Saha, K. R. Fandrick, S. Sanyal, J. Ogikubo, H. Lee, F. Roschangar, J. J. Song, C. H.
Senanayake, Org. Lett. 2011, 13, 5616.
P14 Ancillary Ligand Effects in Donor-Acceptor Re(CO)3(dppz) Complexes
C. B. Larsen, H. van der Salm, N. T. Lucas, K. C. Gordon MacDiarmid Institute for Advanced Materials and Nanotechnology, Department of Chemistry, University of Otago, Dunedin, New Zealand
Dipyridophenazine (dppz) ligands and their complexes have been extensively studied due to their interesting photophysical properties, derived primarily from metal-to-ligand charge transfer (MLCT) transitions to two independent acceptor orbitals on the ligand.1 These transitions result in very different photophysical processes and can be controlled using substitution of the dppz or by manipulating the chemical environment.2
n+ This presentation focuses on the effects of altering the ancillary ligands in [Re(CO)3(dppz)(X)] (X = Cl, n = 0; py, n = 1; dmap, n = 1) complexes on the photophysical properties of sulfur- and amine-based donor-acceptor dppz complexes.3,4 The ligands are highly emissive and show strong intraligand charge transfer (ILCT) transitions, whilst the complexes are shown to have MLCT contributions dependent on both the strength of the donor and the nature of the ancillary ligand. The differing MLCT contributions result in unprecedented and unexpected photophysical properties, which are characterized using electrochemistry, absorption and emission spectroscopy, transient absorption and emission spectroscopy, resonance Raman spectroscopy and TD-DFT calculations.
n+ Left: competing electron transfer processes in donor-appended [Re(CO)3(dppz)(X)] complexes. Right: ligand emission in toluene, dioxane and chloroform.
References: 1. J. Fees, W. Kaim, M. Moscherosch, W. Matheis, J. Klims, M. Krejcik, S. Zalis, Inorg. Chem., 1993, 32, 166. 2. M. K. Brennaman, J. H. Alstrum-Acevedo, C. N. Fleming, P. Jang, T. J. Meyer, J. M. Papanikolas, J. Am. Chem. Soc., 2002, 124, 15094. 3. M. G. Fraser, A. G. Blackman, G. I. S. Irwin, C. P. Easton, K. C. Gordon, Inorg. Chem., 2010, 49, 5180. 4. C. B. Larsen, H. van der Salm, C. A. Clark, A. B. S. Elliott, M. G. Fraser, R. Horvath, N. T. Lucas, X.-Z. Sun, M .W. George, K. C. Gordon, Inorg. Chem., 2014, 53, 1339.
P15 A Dixanthene Scaffold for Cooperative Catalysis
Matthew Mudge,1 Alpesh Patel,1 Mohan Bhadbhade,2 Stephen Colbran.1 1School of Chemistry and 2Mark Wainwright Analytical Center, University of New South Wales, New South Wales, 2052, Australia. [email protected]
This poster is about the enabling synthetic chemistry underpinning our development of new bimetallic organotransition complexes for cooperative catalyses. Targeted are bimetallic complexes with two metal centres that are co-facing but not electronically or mechanically coupled, that is without a rigid or conjugated bridge, as such coupling inevitably deactivates bimetallic catalysts. We chose and report a new aryl-bridged dixanthene scaffold (dX) for construction of the ditopic tetradentate ligands. The dX scaffold was adorned with four diphenylphosphine, four pyrazole or four N-methylimidazolylidene metal binding groups to afford the dXL4 ditopic ligands. Each xanthene moiety is capable of binding a metal centre in bidentate LL or tridentate LOL (e.g., see the Table-of-Contents graphic) modes. Monoxanthene analogues (XL2) have also been made: the XL2 ligands with pyrazole and N-methylimidazolidene metal binding groups are new; that with phosphine groups is a simple analogue of the commercial wide-bite-angle phosphine, Xantphos. Metal coordination studies have begun, and will be described. It is anticipated that the cooperativity within the new bimetallic complexes will lead to emergent reactivity and catalytic efficacies above and beyond those of their monometallic analogues.
a) b)
a) Novel ligands dXL4 (L = diphenylphosphine, pyrazole, and N-methylimidazolylidene metal binding groups) are available from the new dixanthene scaffold dX and can be used to prepare catalysts, (dXL4)[M]2, with + co-facing metal centres. b) View of the [dX(HL)4] cation (HL = N-methylimidazolium) from the X-ray crystal structure of [dX(HL)4][PF6]4.
Acknowledgements: M.M. is grateful to the Graduate Research School, UNSW, for an Australian Postgraduate Award.
P16 Organo-transition metal complexes for electrocatalyic reduction of carbon dioxide
Lida Ezzedinloo,1 Mohan M. Bhadbhade,2 Stephen B. Colbran1 1School of Chemistry, University of New South Wales, Sydney, NSW 2052, Australia E-mail: [email protected] E-mail: [email protected] 2Mark Wainwright Analytical Centre, University of New South Wales, Sydney, NSW 2052, Australia
The depletion of fossil carbon sources together with the increasing global energy consumption demand alternative ways for the sustainable production of fuels and chemicals. The reduction of CO2 to useful products can be achieved using molecular organometallic catalysts.1 The ultimate goal is development of catalytic systems that can selectively convert CO2 into value-added commodity chemicals or high-energy fuels with high efficiencies.
Results will be presented for the preparation, structure and electrochemistry of some new organometallic complexes of multifunctional ligands that incorporate organic hydride donor centres. The complexes efficiently 2 catalyse the electroreduction of CO2 to CO. Foot-of-the-wave analysis of the cyclic voltammetric catalytic responses is used to evaluate rate constants for comparison of our new complexes with known analogues.3
Acknowledgements: We thank the Australian Research Council for partial funding for this project (Grant: DP130103514) and the Australian Synchrotron for (MX-2) beamline access.
References: 1. A. M. Appel, J. E. Bercaw, A. B. Bocarsly, H. Dobbek, D. L. DuBois, M. Dupuis, J. G. Ferry, E. Fujita, R. Hille, P.J. A. Kenis, C. A. Kerfeld, R. H. Morris, C. H. F. Peden, A. R. Portis, S. W. Ragsdale, T. B. Rauchfuss, J. N. H. Reek, L. C. Seefeldt, R. K. Thauer, G. L. Waldrop, Chem. Rev. 2013, 113, 6621. 2. C. Costentin, J.-M. Savéant, ChemElectroChem 2014, 1, 1226. 3. J. M. Smieja, M. D. Sampson, K. A. Grice, E. E. Benson, J. D. Froehlich, C. P. Kubiak, Inorg. Chem. 2013, 52, 2484; J. A. Keith, K. A. Grice, C. P. Kubiak, E. A. Carter, JACS 2013, 135, 15823; J. M. Smieja, E. E. Benson, B. Kumar, K. A. Grice, C. S. Seua, A. J. M. Miller, J. M. Mayer, C. P. Kubiak, PNAS, 2012, 109, 15646.
P17 Dipyridylpyrrolato anion analogues of terpyridine metal complexes
James McPherson,1 Alex McSkimming,1 Mohan Bhadbhade,2 and Steve Colbran1 1School of Chemistry, The University of New South Wales, Sydney, NSW 2052 [email protected] 2Mark Wainwright Analytical Centre, The University of New South Wales, Sydney, NSW 2052
The photophysical and redox properties of transition metal complexes of 2,2':6',2"-terpyridine (terpy) are well understood, and have been extensively exploited as functional units within supramolecular systems.1 Likewise, many terpy-metal complexes exhibit useful catalytic activities.1 2,5-Di(2-pyridyl)pyrroles (dppH) provide a convenient, simple entry point to 2,5-di(2-pyridyl)pyrrolato (dpp–) ligands, which are anionic analogues of terpy. However, the chemistry of dpp– ligands is completely underdeveloped (especially in comparison to the ubiquity of terpy), largely due to the previously reported, difficult, multistep synthetic protocols required to obtain them. We report a new, one-pot, direct condensation route applicable to a wide variety of functionalised dppH from readily available starting materials (Scheme 1).2 The scope of this reaction has been extended to not only accommodate functionalisation at the pyrrole C3/4-positions, but also modification of the pyridyl motifs. For example, a macrocyclic bis(1,10-phenanthrolinyl-2,5-pyrrole) precursor and examples of its rare-earth metal complexes have been prepared.3 This new direct condensation of dppH provides simple access to a broad range of dpp– ligands, overcoming the synthetic hurdles that have stunted their development as metal binding groups to this point. Some organometallic examples of these ligands and the catalysis of electroreduction of CO2 to CO by a ruthenium complex will be presented.
R1 R2 R1 R2 NH4OAc O CHO OHC EtOH, ∆ + N N N N H N dppH (20 – 60 %) Scheme 1: One-pot, direct condensation route to functionalised dppH precursors.
Acknowledgements: We thank the Australian Research Council for partial funding for this project (Grant: DP130103514) and the Australian Synchrotron for (MX-2) beamline access.
References: 1. U. S. Schubert, H. Hofmeier and G. R. Newkome, Modern Terpyridine Chemistry, Wiley-VCH, Weinheim, 2006. 2. A. McSkimming; V. Diachenko; R. London; K. Olrich; C. J. Onie; M. M. Bhadbhade; M. P. Bucknall; R. W. Read; S. B. Colbran, Chem. Eur. J. 2014, 20, 11445. 3. A. McSkimming, S. Shrestha, M. M. Bhadbhade, P. Thordarson, S. B. Colbran, Chem. Asian J. 2014, 9, 136.
P18 Monodentate Ligands For The Stabilisation Of Two Coordinate Magnesium(I) Dimers
Aaron Boutland, Deepak Dange, Laurent Maron*, Andreas Stasch*, Cameron Jones*
School of Chemistry, Monash University, Clayton, Vic. 3800 Université de Toulouse et CNRS, INSA, UPS, UMR 5215, LPCNO, 135 Avenue de Rangueil, F-31077 Toulouse, France Previous work conducted in the Jones/Stasch groups utilised sterically demanding β-diketiminate ligands for the 2+ 1 kinetic stabilisation of magnesium in the +1 oxidation state as a covalently bound Mg2 unit. Initially a synthetic milestone, the magnesium(I) dimers have since found wide use as selective two electron reductants able to be used stoichiometrically towards a variety of inorganic and organic substrates.2 Their reactivity is in part due to the low, three-coordinate environment about the magnesium centre. Presented for the first time is a route to novel magnesium(I) dimers featuring magnesium in a true two-coordinate environment utilising bulky monodentate ligands developed in the Jones group. Magnesium(I) in the two coordinate state has to date only been studied in matrix isolation experiments as the dimeric subhydride Mg2H2 or subhalide Mg2Cl2 which are short-lived at best. The novel two coordinate dimers are stable in solution under ambient conditions. Ligands utilised feature a bulky 2,6-Bis(diphenylmethyl)aniline substituted with a bulky trisubstituted silyl group, which have previously proven useful in accessing low oxidation state group 12-14, and transition metal, compounds.3,4 The novel magnesium dimers are accessed through the reduction of magnesium(II) iodides either by a Mg(I)/Mg(II) redox reaction with the presently known magnesium(I) dimers, or "classical" reducing agents such as sodium metal or KC8. Such magnesium dimers are expected to display greater reactivity than their three- coordinate counterparts owing to their lower coordination environment about the metal centre.
Figure 1: Reduction of (LMgI)2 precursor yielding two coordinate magnesium(I) dimer
Acknowledgements: Cameron Jones, Andreas Stasch, Brant Maitland, Current and past members of Jones/Stasch groups, Australian Research Council, Australian Synchrotron. References: 1. S. P. Green, C. Jones, A. Stasch, Science, 2007, 318, 1754. 2. A. Stasch, C. Jones, Dalton Trans., 2011, 40, 5659. 3. T. Hadlington, M. Hermann, G. Frenking, C. Jones, J. Am. Chem. Soc., 2014, 136, 3028 4. J. Hicks, E. Underhill, C. Kefalidis, L. Maron, C. Jones, Angew. Chem. Int. Ed., 2015, 54, 10000 5. X. Wang, L. Andrews, J. Phys. Chem. A., 2004, 108, 11511 6. R. Kӧppe, P. Henke, H. Schnӧckel, Angew. Chem. Int. Ed., 2008, 47, 8740
P19 Remarkable Thermal Stability of Gold Nanoparticles Utilising Organic and Inorganic
Stabilisers
Andrew McDonagh,1 Shirin Rose King,1 Susan Shimmon,1 Angus Gentle1 1School of Mathematical and Physical Sciences, University of Technology Sydney, Ultimo, NSW 2007. [email protected]
Nanocomposites of gold nanoparticles with ruthenium phthalocyanine (RuPc) complexes or perylene diimide compounds have been synthesised that exhibit remarkably high thermal stability. Electrical resistance measurements revealed that the gold-RuPc nanocomposite is stable up to ~320 °C while the gold-perylene diimide nanocomposite is stable up to ~500 °C. Examination of the nanocomposites and the associated stabilisers using thermogravimetric analysis and differential scanning calorimetry show that the remarkable thermal stability is due entirely to the thermally robust stabilising molecules, which provide an effective barrier to sintering1 of the AuNPs.
Figure 1. A gold nanoparticle / ruthenium phthalocyanine nanocomposite.
Acknowledgements: We acknowledge Jean-Pierre Guerbois and Geoff McCredie for their assistance.
References: 1. M. B. Cortie, M. J. Coutts, C. Ton-That, A. Dowd, V.J. Keast, A. M. McDonagh, J. Phys. Chem. C 2013, 117, 11377.
P20 Understanding N-Heterocyclic Carbene Properties.
Christopher D. Barnett,1 Marcus L. Cole,1 Jason B. Harper1 1School of Chemistry, University of New South Wales, NSW, Australia
N-Heterocyclic carbenes (NHCs) are widely used in chemistry, with numerous applications in organocatalysis and as support ligands for metallo-catalysis. Whilst much effort has been put into the evaluation of steric and electronic properties of NHCs,1 a systematic evaluation of the effect of these properties on the performance of the NHCs in metallo- and organocatalysis is lacking. The work that has been done only compares classes of NHC, such as triazolylidene vs imidazolylidene vs thiazolylidene rather than the much finer control that can be achieved through altering substituents. There is also no real emphasis placed on the steric nature of the systems compared, despite the potential importance of sterics on the properties of an NHC.
The study presented here describes the synthesis and stereoelectronic evaluation of a range of 4,5-substituted imidazol-2-ylidene NHCs (Figure, top left). Employing consistent nitrogen substituents (R in Figure), the electronic properties of a wide range of NHCs have been evaluated using a suite of established ligand donor probes (Figure), and NHC steric properties have been quantified through crystallography. Progress made towards improving the understanding of how to control the properties of NHCs, allowing selection of properties desirable in a given organocatalysis, will be described. A methodology has been developed allowing the tuning of the σ- donation and π-acceptor characteristics of the NHC motifs investigated by selection of the N-substituents and the 4,5-substituents.
References: 1 T. Dröge, F. Glorius, Angew. Chem. Int. Ed. 2010, 49, 6940-6952. 2 C. Tolman, Chem. Rev. 1976, 77, 313-348. 3 A. Liske, K. Verlinden, H. Buhl, K. Schaper, C. Ganter, Organometallics 2013, 32, 5269-5272. 4 Y. Han, H. V. Huynh,T. K. Tan, Organometallics 2007, 26, 6447-6452.
P21 Using Pincer Ligands to Study s- and p-Block Halides and Hydrides
Kai N. Buys,1 Marcus. L. Cole1
1 School of Chemistry, UNSW, Sydney, NSW, 2052, Australia, [email protected]
Several key advancements regarding the stabilisation or activation of s- and p-block organometallic complexes have been reported to date, including (i) the use of tertiary amines or N-heterocyclic carbene (NHC) donors(1, 2, 3) to form highly stable Lewis-adducts and (ii) sterically enshrouding, anionic chelates, e.g. amidinates,(4) triazenides,(5) and β-diketiminates(6) to kinetically and electronically disfavour decomposition. The “bimcaR” ligand class (Figure 1) provides a versatile tridentate bis(NHC) carbazolide framework(7) that beneficially incorporates aspects of all the aforementioned donors.
This work showcases a variety of outcomes that are borne from the coordination chemistry of the bimcaR ligand class with s- and p-block metals (Figure 2), ranging from the activation of group 2 and 14 halides, to the stabilisation of group 13 hydrides.
References: 1. M. Veith, T. Kirs, V. Huch, Z. Anorg. Allg. Chem., 2013, 639, 312. 2. M. L. Cole, S. K. Furfari, M. Kloth, J. Organomet. Chem., 2009, 694, 2934. 3. A. Baishya, M. K. Barman, T. Peddarao, S. Nembenna, J. Organomet Chem., 2014, 769, 112. 4. M. L. Cole, C. Jones, P. C. Junk, M. Kloth, A. Stasch, Chem. Eur. J., 2005, 11, 4482. 5. S. G. Alexander, M. L. Cole, C. M. Forsyth, S. K. Furfari, K. Konstas, Dalton Trans., 2009, 2326. 6. C. Cui, H. W. Roesky, H.-G. Schmidt, M. Noltemeyer, H. Hao, F. Cimpoesu, Angew. Chem. Int. Ed., 2000, 39, 4274. 7. D. Kunz, B. Wucher, M. Moser, Organometallics, 2007, 26, 1024.
P22 Effects of donor/acceptor geometry in organo-ruthenium cruciforms for NLO studies
Anthony Nolan, Mark G Humphrey, Marie. P. Cifuentes,
Research School of Chemistry, Australian National University, Acton ACT 2601, Australia. Email: [email protected]
It is well known that cruciform systems constructed with oligo-phenylethynyl moieties and containing terminal electron donor and acceptor groups often exhibit interesting nonlinear optical (NLO) properties. Previous studies have explored the effect of varying the substitution pattern of donor- and acceptor- groups around a central benzene core in organic compounds [1], since changes in molecular symmetry result in changes in the dipole moment, thus altering the NLO response.
Attaching a transition metal to these organic molecules enhances the NLO properties due to the overlap of the metal d electrons with the conjugated π system. In particular, group 8 metals have been found to greatly increase the NLO response [2], and rutheniumalkynyl compounds offer a good choice due to their high chemical stability compared to many iron and osmium compounds.
The goal of this work is to examine the effects of varying geometries of donor and acceptor groups around the central core in rutheniumalkynyl molecules. In particular, three iosmeric tetrametallic cruciform complexes will be synthesised, with the two terminal nitro (acceptor) groups in a relative ortho, meta and para configurations. The electronic and NLO properties of these isomers will then be measured.
Acknowledgements: We would like to thank the Australian Research Council (ARC) and the Australian National University (ANU) for funding. References: 1. J.J. Miller, J.A. Marsden, M.M. Haley J. Am. Chem. Soc., 2005, 127, 2464 2. G. Grelaud, M.P. Cifuentes, F. Paul, M.G. Humphrey J Organomet Chem., 2014, 751, 181
P23 The Use of Electronically and Sterically Modified β-Diketiminate (nacnac) Ligands for Stabilising Low Oxidation Magnesium and Group 13 and 14 Complexes
Dr. Indrek Pernik, Dr. Andreas Stasch,* Prof. Cameron Jones.*
School of Chemistry, Monash University, Clayton, VIC 3800. Email: [email protected], [email protected], [email protected]
In the Jones group a range of low oxidation complexes have been synthesised by stabilising the formed compounds using sterically demanding ligands.1 This success relies on the fact that these bulky ligands can kinetically stabilise the formed complexes. One group of ligands used for this purpose is β-Diketiminate ligands (also known as nacnac ligands).2 Although successful results were obtained using conventional nacnac ligands with large substituents on the nitrogen atoms (A) the backbone has been observed to be vulnerable towards some reagents (e.g.
3 SiBr4)._ENREF_4 Therefore modified nacnac ligands have been probed and the results are presented in this poster. In particular we are interested in the ligand motifs containing additional nitrogen atoms in the backbone of the ligand (i.e. the central carbon atom of the backbone was replaced with a nitrogen (B) or the incorporation of two dialkyl amino groups instead of the methyl groups (C)). These changes are expected to reduce the reactivity within the backbone and also lead to electronic and steric changes in the ligand.
These modified ligands have proven to be analogous to the previously used bulky nacnac ligands upon reactions with Grignard reagents, allowing for (nacnac)MgI.Et2O complexes, whereas the reduction of the modified ligand containing complexes to the magnesium(I) species require harsher conditions than the unmodified counterparts, or in some cases the reduction did not occur at all.1b Albeit disappointing itself, this indicates the electronic difference which could allow us to obtain other previously unreachable compounds. Hence, these modified ligands have been used to focus on low oxidation group 13 and 14 metal chemistry.
Scheme 1. Simplified overview of the synthetic approach to synthesise low oxidation state magnesium and group 13 and 14 metal containing complexes.
References 1. (a) Protchenko, A. V.; Dange, D.; Harmer, J. R.; Tang, C. Y.; Schwarz, A. D.; Kelly, M. J.; Phillips, N.; Tirfoin, R.; Birjkumar, K. H.; Jones, C.; Kaltsoyannis, N.; Mountford, P.; Aldridge, S. Nat Chem 2014, 6, 315(b) Green, S. P.; Jones, C.; Stasch, A. Science 2007, 318, 1754. 2. Bourget-Merle, L.; Lappert, M. F.; Severn, J. R. Chemical Reviews 2002, 102, 3031. 3. Driess, M.; Yao, S.; Brym, M.; van Wüllen, C.; Lentz, D. J. Am. Chem. Soc. 2006, 128, 9628.
6+ P24 Synthesis of a family of [M2L3] helicates and mesocates derived from bis(bidentate) 2-
pyridyl-1,2,3-triazole “click” ligands: Towards antimicrobial helicates
Roan A. S. Vasdev,1 Dan Preston1 James D. Crowley1 1Department of Chemistry, University of Otago, PO Box 56, Dunedin, New Zealand; E-mail: [email protected]
Helicates and mesocates are part of an exciting new development in anticancer and antibacterial studies.1 Previously in the Crowley group, various helicates and mesocates have been formed using pyridyl-triazole and triazole chelating units (Figure 1).2 A family of iron(II) complexes were generated and examined for biological activity. Unfortunately, these labile iron(II) complexes were rapidly decomposed in the presence of biological nucleophiles and showed no biological activity. A more kinetically inert helical ruthenium(II) analogue was generated and displayed modest antibacterial activity. Disappointingly, efforts to generate a family of ruthenium(II) helicates and mesocates were scuppered by the inert nature of ruthenium(II) ions.2c Very recently Lusby and co-workers have shown that Co(II) can be used to assemble pyridyl-triazole based cages under thermodynamic control.3 These cages can subsequently be “locked” as the inert Co(III) cage upon oxidation. Herein we describe efforts to exploit the method of Lusby to synthesize a family of biologically stable cobalt(III) cylinders with the intention of using them as antimicrobial agents
Figure 2: a) Ligand with the spacer and b) crystal structure of a methylene-linked iron(II) mesocate (counter ions and solvent molecules have been omitted for clarity) Colours: grey, C; blue, N; white, H; orange, Fe.
Acknowledgements: I would like to acknowledge the University of Otago, Department of Chemistry and the Divisions of Sciences for providing funding for this conference.
References: 1. Kaner, R. A.; Scott, P., Future Med. Chem. 2015, 7,1-4. 2. (a) Vellas, S. K.; Lewis, J. E. M.; Shankar, M.; Sagatova, A.; Tyndall, J. D. A.; Monk, B. C.; Fitchett, C. M.; Hanton, L. R.; Crowley, J. D., Molecules 2013, 18,6383-407; (b) McNeill, S. M.; Preston, D.; Lewis, J. E. M.; Robert, A.; Knerr-Rupp, K.; Graham, D. O.; Wright, J. R.; Giles, G. I.; Crowley, J. D., Dalton Trans. 2015, 44,11129-11136; (c) Kumar, S. V.; Lo, W. K. C.; Brooks, H. J. L.; Crowley, J. D., Inorg. Chim. Acta 2015, 425,1-6. 3. Symmers, P. R.; Burke, M. J.; August, D. P.; Thomson, P. I. T.; Nichol, G. S.; Warren, M. R.; Campbell, C. J.; Lusby, P. J., Chem. Sci. 2015, 6,756-760.
P25 Ruthenium Alkynyl Cruciforms and the Solubility Conundrum
Mahbod Morshedi, Ellen F. Phiddian, Marie P. Cifuentes, Mark G. Humphrey
Research School of Chemistry, Australian National University, ACT 2601, Australia Email: [email protected]
The effects of symmetry on nonlinear optical (NLO) responses can give new insights into the mechanisms involved in optimization of NLO properties.[1]. Conjugated π-extended systems based on phenyleneethynylene scaffolding are of significant interest, since tweaking basic structural motifs can lead to collective understanding of third-order NLO responses.[2] Although organic phenylethynyl-based cruciforms are well established, organometallic derivatives with such symmetry are less known. Herein, the synthesis of a series of donor-acceptor substituted 1,2,4,5-tetrakis(phenylethynyl)benzenes is presented. The insolubility of some derivatives is also described.
Acknowledgements: We thank the Australian Research Council for funding and support.
References: [1] a) C. Bosshard, R. Spreiter, P. Günter, R. R. Trkwinski, M. Schreiber, F. Diederich, Adv. Mater. 1996, 8, 231-234; b) K. Ohta, S. Yamada, K. Kamada, A. D. Slepkov, F. A. Hegmann, R. R. Tykwinski, L. D. Shirtcliff, M. M. Haley, P. Sałek, F. Gel’mukhanov, H. Ågren, J. Phys. Chem. A 2011, 115, 105-117; c) X.-B. Zhang, J.-K. Feng, A.-M. Ren, C.-C. Sun, Opt. Mater. 2007, 29, 955-962. [2] a) J. A. Marsden, J. J. Miller, L. D. Shirtcliff, M. M. Haley, J. Am. Chem. Soc. 2005, 127, 2464-2476; b) E. L. Spitler, J. M. Monson, M. M. Haley, J. Org. Chem. 2008, 73, 2211-2223.
P26 The Kinetic Stabilisation of Main Group and Transition Metal Complexes with a Super
Bulky Diiminopyridine
Vera Diachenko,1 Marcus Cole1 1The University of New South Wales, Sydney NSW 2052; [email protected]
Diiminopyridines are neutral, tridentate N,N’,N’’-donors that have been widely used in both main group and transition metal chemistry. This class of ligand offers the advantages of both thermodynamic stabilisation through tridentate chelation and kinetic stabilisation through highly modifiable imine substituents. They have been recently shown to stabilise otherwise highly reactive species, including low and even zero oxidation state group 13 and 14 complexes.1 Thus, sterically bulky diiminopyridines are promising frameworks for the kinetic stabilisation of low oxidation state main group complexes, main group hydride complexes, and first row transition metal complexes as potential redox active catalysts. Herein, a super bulky diiminopyridine (Dimpy*), with 2,6-dibenzhydryl-4-methylphenyl (Dipp*) substituents, has been developed and its coordination chemistry with group 13 halides, alkyls and hydrides explored; as well its coordination chemistry with first row transition metals. Additionally, the kinetic stabilisation of low valent group 13 and 14 complexes with weakly coordinating anions (WCAs) has been explored, with future investigation into its reactivity with low basicity hydride sources as a possible route to heavy metal hydrides through oxidative addition or halide-hydride exchange.
Acknowledgements: The Australian Government for an APA, Dr Donald Thomas for assistance with ESR measurements, Mr Anthony Leverett for X-ray crystallography and Mr Nick De Haas for assistance on transition metal studies.
References: 1. (a) Richeson, D. S.; Gorelsky, S. et al. J. Am. Chem. Soc. 2009, 131, 4608. (b) Nikonov, G. I. et al. Angew. Chem. Int. Ed. 2014, 53, 2711. (c) Fischer, R. C.; Flock, M. et al. Chem. Eur. J. 2013, 19, 15504.
P27 Weak Te-Te Interactions in Naphthalene and related scaffolds
K. S. Athukorala Arachchige, F.R. Knight, L. M. Diamond, M. Bühl, A.M.Z. Slawin, J.D. Woollins
University of St Andrews, EaStCHEM School of Chemistry, St Andrews, United Kingdom. E-mail: [email protected]
Interactions of atoms between molecules or within molecules is an important aspect of chemistry.1 There has been a great development in the knowledge of covalent and ionic bonding.1,2 One of the main difficulties is to develop a thorough understanding of weak non-covalent interactions. These intra-molecular or intermolecular interactions can be attractive or repulsive in nature. A rigid scaffold that is used to achieve such spatial proximity is the naphthalene framework, in which substituent’s are in the peri (1,8) positions and have a typical separation of around 3Å.3 The spin–spin coupling constant (SSCC) is a good indicator from which to investigate such bonding in these systems. For instance, observation of spin–spin coupling across hydrogen bonds has been taken as evidence for covalent contributions to this kind of bonding.4 Te substituent’s, which are formally non-bonded, show significantly shorter peri distances than the sum of the van-der-Waals radii, a result of weak donor–acceptor interactions and the onset of 3-center-4-electron (3c4e) bonding.
Figure 1. Te-Te Coupling Pathway – Through Coupling Deformation Density(CDD)
We have utilised crystallography and a combination of NMR and density functional theory (DFT) to study the interactions between formally nonbonded, but spatially close Te atoms. We observed that weak donor–acceptor interactions in the peri-naphthalene system, which mark the onset of 3c-4e bonding, reinforce the Te,Te couplings and lead to unusually large J(125Te,125Te). In the broader aspect of well-known through-space spin–spin coupling, this conformational aspect is a new feature and its worth exploring. Studies are under way to investigate how substituents at the phenyl rings can modulate the bonding and the associated NMR properties; enabling us to broaden our knowledge of the very foundation of chemistry, the chemical bond.
References:
1. G. P. Moss, Pure Appl. Chem., 1996, 68, 2193-2222. 2. C. Bleiholder, R. Gleiter, Werz, D. B. Köppel, H, Inorg. Chem., 2007, 46, 2249- 2260. 3. M. Bühl, F. R. Knight, A. K. Irina, M.O, Olga, L. M. Rebecca, A. M. Z. Slawin, J.D. Woollins, Angew. Chem. Int. Ed., 2013, 52, 2495 –2498. 4. A. D. Dingley, S. Grzesiek,J. Am. Chem. Soc., 1998, 120, 8293 –8297.
P28 Synthesis of Novel Platinum Poly-ynes with Pendant Liquid Crystalline Cores
Muhammad Younus and Salhed Ahmed
Department of Chemistry, Shahjalal University of Science and Technology, Sylhet 3114, Bangladesh. E-mail: [email protected]
The continued dominance of liquid crystal displays (LCDs) is now being challenged by the rapid improvement of highly emissive and, potentially, more efficient organic light emitting displays (OLEDs) made of conjugated polymers [1]. There are two aspects which makes the use of oriented liquid crystalline materials in OLEDs attractive. The first property of well aligned liquid crystalline film from conjugated materials is their high charge carrier mobility. The second important property of the rod-like emitters aligned parallel to each other is their polarized emission. In a further breakthrough, it has been demonstrated that the addition of heavy metal (Ir and Pt) to the LC materials can increase the efficiency of OLEDs from 25% (fluorescent singlet emitter) to 100% (phosphorescent triplet emitter). As a part of our continued research on transition metal poly-ynes, a novel series of platinum containing poly-ynes with pendant liquid crystalline (LC) cores has been made by the dehydrohalogenation reaction between platinum dichlorides and LC core containing diterminal acetylene (scheme 1). The synthesis of biphenyl based LC cores and their introduction into the polymer precursor will be presented in the poster.
Scheme 1 Synthesis of Platinum Containing Poly-ynes with Pendant Liquid Crystalline Cores All the new compounds have been characterized by spectroscopic and analytical techniques. The molecular weights of the poly-ynes have been determined by the gel permeation chromatography (GPC). The phase behavior of the materials has been identified by the use of differential scanning calorimetry (DSC), polarized optical microscopy (POM) and X-ray crystallography. The studies of the optoelectronic properties of these materials are in progress.
Acknowledgements: This work is supported by the Higher Education Quality Enhancement Project (HEQEP) of the University Grants Commission of Bangladesh.
References: 1. R. H. Friend, R. W. Gymer, A. B. Holmes, J. H. Burroughes et al., Nature, 1999, 397, 121.
P29 Synthesis, characterisation and biological applications of
haloformamidinatoantimony(III) complexes
Areej Aldabbagh 1, Peter Junk1 and Jun Wang2
[email protected] 1College of Science, Technology & Engineering, Building 21, James Cook University, Townsville, Qld, 4811, Australia. 2School of Chemistry, Monash University, Victoria, Australia
Redox transmetallation/ligand exchange between a metal, a diarylmercurial, and a protonated ligand, has been successfully performed for the lanthanoid elements, [1-5] and for the more electropositive alkaline earth metals.We now report the synthesis and structural characterisation of new haloformamidinatoantimony(III)complex[Sb(DippForm)(C6F5)X(thf)2] through the redox transmetallation/ ligand exchange reactions. Since bis-(pentafluorophenyl) - mercury is one of the main reagents in the experimental, it was synthesized in the first step. Moreover, [Sb(DippForm)(C6F5)X(thf)2] was prepared from reaction of SbCl3 compound(0.22 g, mmol) with Hg(C6F5)2 (0.45 g, mmol) and N,N′-bis(2,6-diisopropyl)phenylformamidine (0.36 g, mmol) in 30 mL THF. The mixture turned bright brown after stirring one week. After filtration, the solvent was evaporated under vacuum, the remaining solution was left to crystallise in the fridge for two days. Crystallization from THF produced [Sb(DippForm)(C6F5)X(thf)2] (Fig.1) (Eq.1).
THF [SbL(C F )Cl] + 2H(C F ) + 2HgCl 2LH + 2Hg(C6F5)2+ 2SbCl3 6 5 2 6 5 2
(Equation 1)
Fig. 1. Crystal structure of synthesized [Sb(DippForm)(C6F5)X(thf)2]
Acknowledgements:
We thank Australian Research Council for support. Aspects of this research were undertaken on the MX1 beamline at the Australian Synchrotron, Victoria, Australia.
References 1. G. B. Deacon and C. M. Forsyth, Inorganic Chemistry Highlights, ed.E. G. Meyer, D. Naumann and L. Wesemann, Wiley-VCH, Germany, 2002, ch. 7, 139. 2. G. B. Deacon, G. D. Fallon, C. M. Forsyth, S. C. Harris, P. C. Junk,B. W. Skelton and A.H. White, Dalton Trans., 2006, 802. 3. G. B. Deacon and C. M. Forsyth, Chem. Eur. J., 2004, 10, 1798. 4. G. B. Deacon and C. M. Forsyth, Organometallics, 2003, 22, 1349. 5. M. L. Cole, G. B. Deacon, C. M. Forsyth, K. Konstas and P. C. Junk, Dalton Transactions, 2006, DOI: 10.1039/B602210C, 3360-3367.
P30 Synthesis of rare earth complexes involving N,N'-diphenylformamidine ligand
M. Salehisaki,1 P. C. Junk,1 J. Wang1 1College of Science, Technology & Engineering, Building 21, James Cook University, Townsville, Qld, 4811, Australia.
Rare Earth (RE) elements such as Y and Er were used in Redox Transmetallation/Protolysis (RTP) reactions to synthesize organometallic compounds. Bis-(pentafluorophenyl)-mercury was synthesized and used as the oxidant reagent for RTP reactions. As the results of the reactions between the RE elements and N,N'-diphenylformamidine
(DiphFormH) ligand (Scheme 1), two new compounds of [Y(DiphForm)3(thf)2] and [Er(DiphForm)3(thf)] were formed in good yields of 54% and 70% respectively (Figure 1). The results of 1H NMR spectra confirms the complete deprotonation of the formamidine in the RTP reaction. Different organometallic compounds involving RE elements have been synthesized by treatment of various bulky variants of N,N’-bis(aryl)formamidine ligands with the same chemical route.[1, 2] However, more reactivity is expected for the new compounds considering their less bulky structures and greater accessibility of the metal centers.
Scheme 1. Structure of DiphFormH.
Figure 1. X-ray Structure of [Y(DiphForm)3(thf)2] (left) and [Er(DiphForm)3(thf)] (right).
Acknowledgements: This work was supported by the Australian Research Council and James Cook University postgraduate award. Some aspects of this research were undertaken on the MX1 beamline at the Australian Synchrotron, Victoria, Australia.
References: 1. M. L. Cole, G. B. Deacon, C. M. Forsyth, P. C. Junk, K. Konstas and J. Wang, Chem-Eur. J., 2007, 13, 8092. 2. S. Hamidi, L. N. Jende, H. Martin Dietrich, C. c. Maichle-Mössmer, K. W. Törnroos, G. B. Deacon, P. C. Junk and R. Anwander, Organometallics, 2013, 32, 1209.
P31 Homo- and Heterobimetallic Complexes Used as Catalysts for a Range of Organic
Transformations: Lessons Learned
Mark R.D. Gatus1,2 and Barbara A. Messerle1,2 1Chemistry and Biomolecular Sciences, Macquarie University, North Ryde, 2109, Sydney, Australia. 2School of Chemistry, University of New South Wales, Kensington, 2052, Sydney, Australia. [email protected]
Bimetallic catalysts, both homo- and heterobimetallic, can exhibit unique cooperative properties such as enhanced reaction rates1 and selectivities2 in comparison to their monometallic counterparts. It has been demonstrated that the degree of intermetallic cooperativity achieved using bimetallic complexes can be dependent on the distance between the metal pairs.2,3 Heterobimetallic complexes, which contain two different metal centres, are of particular interest due to their ability to promote two or more different transformations in one pot. However, the predictability of whether a particular bimetallic complex will catalyse one or more reaction steps more efficiently than a monometallic complex is not straightforward.
We have investigated a range of Rh(I) homobimetallic complexes anchored on various rigid and flexible scaffolds (1) in addition to homo- and heterobimetallic complexes containing pairs of heteroditopic ligands (2). The bimetallic complexes were tested as catalysts for C-X bond formation reactions and were compared to their monometallic half units. While in most cases the bimetallic complexes outperform the monometallic half units, we found that in some catalysed reactions, bimetallic complexes that contain an Ir(I) N-heterocyclic carbene (NHC) complex behaved in an unusual and unexpected manner. Further investigation of the catalytic activity of two simple monometallic Ir(I) NHC complex (3 & 4) has revealed some interesting results which will also be presented.
M2 [BArF ] OC CO OC CO 4 2 N N N N CO CO Rh Rh M1 N N N N Ir CO N N N N Ir CO O N Cl N N N N N Cl
Various Scaffolds M1 = Ir(CO)2Cl or Rh(CO)2Cl 3 4 1 M2 = Ir(CO)2Cl or Rh(CO)2Cl 2 References: 1. Ho. J. H. H, Choy. S. W. S, Macgregor. S. A, Messerle. B. A, Organometallics, 2011, 30, 5978. 2. Broussard. M. E, Juma. B, Train. S. G, Peng. W. J, Laneman. S. A, Stanley. G. G, Science, 1993, 260, 1784. 3. Li. H, Marks. T. J, PNAS, 2006, 103, 15295.
P32 Synthesis of the First Reported Cyclic (alkyl)(amino)Carbene (CAAC)-Group 13 Metal
(M= Al, Ga, or In) Complexes
Jacques Atkinson-Bodourian, Dr. Deepak Dange and Prof. Cameron Jones School of Chemistry, Monash University, Clayton, VIC, 3800. Email: [email protected], [email protected], [email protected]
Interest in the chemistry of the main group elements has increased over the past decades primarily due to the stabilization of highly reactive complexes containing the metals in the low oxidation state.1 In recent years, the emergence of N-heterocyclic carbenes (NHCs) has led to the development of a wide array of low oxidation state, main group and transition metal complexes. More recently, alternative cyclic (alkyl)(amino)carbene (CAAC) species have been used to accomplish similar chemistry. Though CAACs are stronger nucleophiles and π-acids than NHCs. Recent work on the stabilization of the first reported silyone (a silicon(0) compound) and germylone compounds (germanium(0) compounds) was accomplished utilizing CAACs as the ligand.2,3
Me Within the Jones Group the use of two CAAC ligands (CAAC = :C-(CR2)(CH2)(CMe2)N(Dipp); CAAC when Cy R = CH3; CAAC when R = C5H10) have allowed the synthesis of a number of novel CAAC-Group 13 4 complexes of the type (CAAC)MX3 (M= Al, Ga, or In; X = Cl, Br, or In) (Figure 1.).
It is ongoing work to successfully reduce these CAAC-group 13(III) metal halide species to form low oxidation state analogues. Early qualitative observations have indicated possible reactivity of these species with the Mg(I) Mes reducing agent [{(MesNacnac)Mg}2]( Nacnac = [(MesNCMe)2CH]−), Mes = 2,4,6-trimethylphenyl), although work in this area is still being developed. Future work looks to extend our reduction studies in attempts to form the CAAC-group 13 metal(I) and (0) species whilst increasing the steric bulk of the CAAC ligands.
Figure 1. Preparation of RCAAC aluminium and gallium halide adduct complexes
References: 1. Jones, C.; Koutsantonis, G.A. Aust. J. Chem. 2013, 66, 1115-1117 2. Li, Y.; Mondal, K.C.; Roesky, H.W.; Zhu, H.; Stollberg, P.; Herbst-Irmer, R.; Stalke, D.; Andrada, D.M. J. Am. Chem. Soc. 2013, 135, 12422-12428. 3. Mondal, K.C.; Roesky, H.W.; Schwarzer, M.C.; Frenking, G.; Niepötter, B.; Wolf, H.; Herbst-Irmer, R.; Stalke, D. Angew. Chem. Int. Ed. 2013, 52, 2962 – 2967. 4. Lavallo, Y.; Canac, Y.; Prsang, C.; Donnadieu, B.; Bertrand, G. Angew. Chem. Int. Ed. 2005, 44, 5705- 5709
P33 Photophysical trends in iridium(III) tetrazolate complexes
Chiara Caporalea, Stefano Stagnib, Max Massia
aDepartment of Chemistry, Curtin University, Perth, Australia bDepartment of Industrial Chemistry, University of Bologna, Italy email: [email protected]
In the past decade, luminescent transition metal complexes have been developed for applications in organic light- emitting devices (OLEDs), in solar cells, as well as probes for biological labelling.1 d6-Complexes of ruthenium(II), rhenium(I), iridium(III) and d8-complexes of platinum(II) have been predominantly studied. Easily tunable excitation and emission wavelength can be achieved with the appropriate choice and modification of ligands,2 a property that can be exploited for the optimisation of these species tailored to specific applications. We have recently focused our attention to the synthesis and photophysical investigation of a series of iridium(III) tetrazolate complexes. Despite the fact that complexes bound to diimine ligands such as 2,2’-bipyridine and 1,10- phenanthroline have been widely reported in literature, the use of tetrazolate moiety has received comparably less attention in the area of luminescent iridium complexes. We show that modifications of the chemical structure of the chelating ligands can significantly alter the photophysical properties of a small library of complexes. Additionally, we have proved the reactivity of these complexes toward Suzuki-type coupling reactions.
Acknowledgements: The ARC and Curtin University are gratefully acknowledged for funding.
References:
1 F. L. Thorp-Greenwood, R. G. Balasingham and M. P. Coogan, J. Organomet. Chem., 2012, 714, 12–21.
2 S. Stagni, S. Colella, A. Palazzi, G. Valenti, S. Zacchini, F. Paolucci, M. Marcaccio, R. Q. Albuquerque and L. De Cola, Inorg. Chem., 2008, 47, 10509–10521.
P34 Group 8 and 9 Complexes Bearing an Anionic Carbon Centred Podand Ligand
Samantha K. Furfari,1 Alison M. Magill,1 Ryan J. Gilbert-Wilson,1 Leslie D. Field1 1School of Chemistry, University of New South Wales, Sydney, NSW, Australia, 2052
Podand ligands with an anionic group 14 element as the anchor point (i.e., C, Si, Ge) provide a covalent metal- element bond that have demonstrated to be a strong, robust bond in addition to serving as a concrete anchor point for the ligand.1
Reports on this class of ligand are increasing2,3and we have reported a number of ruthenium complexes based on 1 the carbon-centred podand ligand; HC(CH2CH2PPh2)3. Metal complexes containing a similar framework with a silicon anchor were first reported by Hendriksen et al.3 and Joslin and Stobart4 and such complexes are now of interest to dinitrogen activation chemistry.5
We are interested in exploring synthetic approaches to access dinitrogen complexes of group 8 and 9 metals with new anionic CP3 ligands and investigating the reactivity of these new dinitrogen complexes (Scheme 1). We are also investigating different analytical techniques to quantify the ammonia produced from reactions of dinitrogen complexes.
iPr PiPr PCy 2 2 Cy2 2 N iii H P P N R P PR i, ii 2 C 2 Rh N N Ru C C H i P Pr2 PCy2 PR2 3 1 2
o t o i. 0.5 [RhCl(cod)] 2, THF, 125 C, 3 hrs ii. 1.2 KO Bu, N2, THF, 40 C, O/N o iii. [RuH2(N2)(PPh 3)]2, Toluene, 120 C, O/N
iPr Cy Scheme 1: Synthesis of [Rh(CP3 )(N2)] (2) and [RuH(CP3 )(N2)] (3)
Acknowlegments The authors would like to thank Martin Bucknall (BMSF, MWAC) for the GC analysis, Mohan Bhadbhade (SSEAU, MWAC) for the X-ray crystallography, the staff at the NMR facility (MWAC) and UNSW for funding.
References: 1. O. R. Allen, L. D. Field, A. M. Magill, et al., Organometallics, 2011, 30, 6433-6440 2. M. Ciclosi, J. Lloret, F, Estevan, et al., Angew. Chem. Int. Ed., 2006, 45, 6741-6744 3. D. E. Hendriksen, A.A. Oswald, G. B. Ansell, et al., Organometallics, 1989, 8, 1153-1157 4. F. L. Joslin, S. R Stobart, J. Chem. Soc. Chem. Comm., 1989, 504-505 J. C. Peters, et al., Organometallics, 2009, 28, 3744-3753; Inorg. Chem., 2009, 48, 2507-2517; Angew. Chem. Int. Ed., 2007, 46, 5768-5771; Nature Chem., 2010, 2, 558-565
P35 Protonation of Dinitrogen to Ammonia on Ruthenium and Iron Complexes Containing
Tripodal Phosphine Ligands
P. Manohari Abeysinghe,1 Leslie D. Field,1 Hsiu L. Li,1 Thomas O. Peters,1 Scott J. Dalgarno,2 Ruaraidh D. McIntosh2 1School of Chemistry, University of New South Wales, NSW 2052, Australia E-mail: [email protected] 2School of EPS-Chemistry, Heriot-Watt University, Edinburgh, Scotland, U. K. EH14 4AS
Catalytic conversion of dinitrogen to ammonia utilising molybdenum and iron complexes has recently been reported.1 While ruthenium is not found in biological systems, it is a catalyst component in some industrial processes for ammonia production2 and ruthenium has been reported as the key metal in heterogeneous nitrogen fixation3 as well as nitrogen reduction by electrochemical means.4 As far as we are aware, so far no known examples of homogeneous chemical transformation of dinitrogen to ammonia have been reported for ruthenium complexes. We have previously reported the treatment of Fe(0) dinitrogen complexes containing bidentate phosphine ligands [Fe(N2)(PP)2] (PP = 1,2-bis(diethylphosphino)ethane (depe), 1,2-bis(dimethylphosphino)ethane (dmpe)) with acids, such as hydrochloric acid or triflic acid, which resulted in reaction at the metal centre rather than at the dinitrogen ligand. Treatment of [Fe(N2)(dmpe)2] with trimethylsilyl triflate then triflic acid, however, afforded ammonium.5 We have now extended our studies to iron and ruthenium dinitrogen complexes containing i R the tripodal phosphine ligands P(CH2CH2PR2)3 where R = Pr, Ph, Cy (PP3 ). In contrast to the earlier complexes R with bidentate phosphine ligands, nearly all of the Ru and Fe dinitrogen complexes containing PP3 ligands react with acid to form ammonium.
Acknowledgements: We gratefully acknowledge funding from UNSW. References: 1. K. Arashiba, E. Kinoshita, S. Kuriyama, A. Eizawa, K. Nakajima, H. Tanaka, K. Yoshizawa, Y. Nishibayashi, J. Am. Chem. Soc., 2015, 137, 5666; S. E. Creutz, J. C. Peters, J. Am. Chem. Soc., 2014, 136, 1105. 2. G. Maxwell (Ed.), Synthetic Nitrogen Products: A Practical Guide to the Products and Processes, 2004, p. 388 (Springer: US). 3. M. Kitano, Y. Inoue, Y. Yamazaki, F. Hayashi, S. Kanbara, S. Matsuishi, T. Yokoyama, S.-W. Kim, M. Hara, H. Hosono, Nat. Chem., 2012, 4, 934. 4. C. J. M. van der Ham, M. T. M. Koper, D. G. H. Hetterscheid, Chem. Soc. Rev., 2014, 43, 5183. 5. L. D. Field, N. Hazari, H. L. Li, Inorg. Chem., 2015, 54, 4768.
P36 Homoleptic Au(III) trications: A synthetic pathway to a novel class of Au(III) compounds
Robert Corbo, Thomas P. Pell, David J. D. Wilson, Peter J. Barnard and Jason L. Dutton*
Department of Chemistry, La Trobe Institute for Molecular Science, La Trobe University, Melbourne,
Victoria, Australia
The investigation of high-oxidation state late transition metals, especially palladium, is a topic of current interest in organometallic chemistry. I(III) reagents such as PhICl2 and PhI(OAc)2 have been used to access Pd(IV) in a variety of stoichiometric and catalytic transformations.1 Our group have used the dicationic I(III) reagent, 2+ [PhI(R)2] (R = pyridine, 4-dimethylaminopyridine, 4-cyanopyridine), to generate both Pd(IV) and Pt(IV) complexes.2
Scheme 1: Synthetic route to the homoleptic gold (III) trication and reactivity studies
We report the use of the aforementioned I(III) dications in the synthesis of the first examples of Au(III) tricationic complexes bound only by neutral monodentate ligands.3 Oxidation of the bis-pyridine Au(I) cation 3+ allows access to the homoleptic and pseudo-homoleptic Au(III) complexes: [Au(DMAP)2(pyr)2] (Scheme 1). The oxidation reactions are facile, cleanly furnishing the Au(III) products, demonstrating the efficacy of 2 PhI(pyr)2] as a halide-free oxidant for Au(I). The Au(III) trications show intriguing reactivity, yielding dinuclear oxo-bridged and terminal hydroxide complexes when exposed to water, acetylene insertion, and facile ligand exchange reactions.
(1) Deprez, N. R.; Sanford, M. S. J. Am. Chem. Soc. 2009, 131, 11234–11241.
(2) Corbo, R.; Georgiou, D. C.; Wilson, D. J. D.; Dutton, J. L. Inorg. Chem. 2014, 53 (3), 1690–1698.
(3) Corbo, R.; Pell, T. P.; Stringer, B. D.; Hogan, C. F.; Wilson, D. J. D.; Barnard, P. J.; Dutton, J. L. J. Am. Chem. Soc. 2014, 136, 12415–12421.
P37 Configuration-Dependent Kinetic Indenyl Effects in Metal-Centered Epimers of
η5:κ2(C,S)-Indenyl-Phenethylsulfanyl Rhodacycles
Robert W. Baker School of Chemistry, University of Sydney, Sydney, NSW 2006, Australia. [email protected]
The term indenyl effect was first coined by Basolo and co-workers1 to describe the remarkable increases (ca. 108) in the rates of substitution reactions for the indenyl complexes [η5-C9H7Rh(CO)2] and [η5-C9H7Mn(CO)3] when compared to the cyclopentadienyl analogues. In addition to kinetic effects, related ground state effects are also 2 apparent in indenyl-metal complexes, such as slip-fold distortions towards η3-coordination, as well as conformational effects, which have been termed structural indenyl effects by Zanello and co-workers.3 Recently we have shown that structural indenyl effects can control metal-centered chirality in η5:κS-indenyl-sulfanyl and -sulfinyl rhodacycles of 2-phenylpyridine.4 New results establish that substantial differences in kinetic indenyl effects occur between metal-centered epimers of η5:κ2(C,S)-indenyl-phenethylsulfanyl rhodacycles.
References: 1. M. E. Rerek, L.-N. Ji, F. Basolo, J. Chem. Soc., Chem. Commun., 1983, 1208. 2. V. Cadierno, J. Díez, M. P. Gamasa, J. Gimeno, E. Lastra, Coord. Chem. Rev., 1999, 193−195, 147. 3. G. Scott, A. McAnaw, D. McKay, A. S. F. Boyd, E. Ellis, G. M. Rosair, S. A. Macgregor, A. J. Welch, F. Laschi, F. Rossib, P. Zanello, Dalton Trans., 2010, 39, 5286. 4. R. W. Baker, P. Turner, I. J. Luck, Organometallics, 2015, 34, 1751.
P38 Tumour Selective Gadolinium Agents for Binary Cancer Therapies
A. J. Hall, M. T. Kardashinsky, and L. M. Rendina School of Chemistry, The University of Sydney, Sydney, NSW, 2006, email: [email protected]
Glioblastoma multiforme (GBM) is an aggressive primary brain tumour, the current standard of treatments (i.e. surgical resection, followed by adjuvant radiotherapy and concurrent chemotherapy with temozolomide) produces a median survival time of approximately 15 months. Binary therapies offer a greater level of control over other treatment options for patients with invasive non-operable cancers as they involve two innocuous components that selectively combine to give a lethal effect that is localized to tumour cells.
The current study investigates novel gadolinium(III) agents, that upon excitation via neutron or X-ray photon capture produce an Auger and Coster-Kronig (ACK) electron cascade that in turn interacts with water to produce hydroxyl radicals that propagate oxidative damage over a range of ca. 12.5 nm.[1] This short range means that the lethal effect is restricted to the cell that localises the drug, but also necessitates that the heavy atom excitation occurs in proximity to critical sub-cellular components. The mitochondria of aggressive tumours such as GBM present ideal candidates for therapeutics with this mode of action, as they are vital to cell function and differ from endogenous cell mitochondria through their elevated mitochondrial membrane potential.
Previous pioneering work conducted by the Rendina group shows that a new class of phosphonium-based targeting moieties are up to 60-fold selective for T98G human glioblastoma cells over normal, healthy cell lines such as SVG p12 (glial) (Fig. 1). The complexes also show significantly increased accumulation in their mitochondria over the cytosol, and are relatively non-toxic (mM).[2] This work builds on our understanding of the targeting component of our drugs by using a range of structural analogues (Fig. 2), while also improving the toxicity and stability of our drugs that are otherwise liable to transmetallation in the acidic compartments of the cell. By inserting an additional donor atom into the chelating scaffold, we anticipate an improvement in the gadolinium(III) complexation behaviour of the ligands and complex stability. The key results of this work will be presented.
References: 1. De Stasio, G., Rajesh, D., Casalbore, P., Daniels, M.J., Erhardt, R.J, Frazer, B.H., Wiese, L.M., Richter, K.L., Sonderegger, B.R., Gilbert, B., Schaub, S., Cannara, R.J., Crawford, J.F., Gilles, et al., Are gadolinium contrast agents suitable for gadolinium neutron capture therapy? Neurological Research, 2005, 27, 387-398. 2. Morrison, D.E., Aitken, J.B., De Jonge, M.D., Issa, F., Harris, H.H., Rendina, L.M. Synthesis and biological evaluation of a class of mitochondrially-targeted gadolinium(III) agents, Chemistry - A European Journal, 2014, 20, 16602-16612.
P39 New Platinum Octupolar Complexes for Nonlinear Optics
Suzy Streatfield1,2, Mark G. Humphrey1, Marie P. Cifuentes1, Frédéric Paul2 1Research School of Chemistry, Australian National University, Acton ACT 2601, Australia 2Institut des Sciences Chimiques de Rennes, Université de Rennes 1, 35042 Rennes Cedex, France
Recently, investigations into materials exhibiting nonlinear optical (NLO) properties have become increasingly common due to their potential applications in the photonics industry. Attention originally focused on inorganic salts, but the focus has shifted to both organic and organometallic materials, which offer greater design flexibility and faster response times[1]. Transition metal alkynyl complexes offer great promise due to their rigid framework, relative synthetic ease and the combination of highly conjugated organic frameworks with the electron accepting or donating character of transition metals[2]. This work focuses on platinum complexes which are good candidates for optical limiting applications, due to the facile intersystem-crossing (promoting reverse-saturable absorption) and higher transparency of these complexes (compared with other metals)[3]. As high-powered lasers are becoming more commonplace, optical limiters are vital in providing protection for both eyes and optical components[4].
Here we report the investigation into a variety of octupolar platinum acetylide complexes. Several different central cores were investigated including 1,3,5-benzene, 1,3,5-isocyanurate (triazinane-2,4,6-trione) and 1,3,5-triazine derivatives. Different capping alkynyl ligands were utilised to assess the implication on the third-order NLO effects, by varying the electronegativity of the end groups and the aryl systems used.
Acknowledgements: We would like to thank the Australian Research Council (ARC), the Australian National University (ANU), the Australian Nanotechnology Network (ANN), Université de Rennes 1 (UR1) and the CNRS for funding.
References: 1. G. Grelaud, M. P. Cifuentes, F. Paul, M. G. Humphrey, J. Organomet. Chem., 2014, 751, 181. 2. P. Lind , D. Boström, M. Carlsson, A. Eriksson, E. Glimsdal, M. Lindgren, B. Eliasson, J. Phys. Chem. A., 2007, 111, 1598. 3. T. Kindahl, J. Öhgren, C. Lopes, B. Eliasson, Tetrahedron Lett., 2013, 54, 2403. 4. C. Liao, A. H. Shelton, K.-Y. Kim, K. S. Schanze, ACS Appl. Mater. Interfaces, 2011, 3, 3225.
P40 Utilising Bulky Monodentate Alkyl/Aryl Substituted Amido-Ligands to Stabilise Low
Oxidation State Silicon Compounds
John Kelly, Cameron Jones* School of Chemistry, Monash University, Wellington Rd, Clayton VIC 3800 Email: [email protected]
Interest in low oxidation state heavy group 14 compounds has increased in recent times due to their unique reactivity, especially in terms of “transition metal-like” catalysis and small molecule activation.1 In the past this behavior has predominately been in lain with germanium and tin compounds due to the increased stability of the +2 oxidation state of these elements compared to that of silicon.2 Contemporary research has led to a facile route to low oxidation state silicon compounds via dehydrohalognation using bases, as opposed to the more standard reduction using alkali/ alkaline earth metals.3 Generally, low oxidation state acyclic silicon compounds have been stabilised using bulky monodentate silyl or aryl donor ligands with scarce examples using monodentate amide ligands.4 Our research has shown that, using robust alkyl/aryl amide ligands, that it is possible to isolate novel low oxidation state silicon compounds, including the unprecedented dihydrodiamido disilene (1). This is achieved utilising tetramethyl N-heterocyclic carbene (TMC) as a hydrogen chloride abstractor. By altering the halogen/hydrogen ratio at the silicon center it is possible to isolate the carbene-stabilised amino chloro silylene (2), which we propose can act as a precursor to many interesting low oxidation state silicon compounds,e.g. two coordinate acyclic silylenes.
References: 1. (a) T.J. Hadlington, M. Hermann, G. Frenking and C. Jones, J. Am. Chem.Soc., 2014, 136, 3028 – 3031. (b) T.J. Hadlington, J. Li, A. Davey, M. Hermann, G. Frenking and C. Jones, Organometallics, 2015, 34, 3175 – 3185. 2. M. Seth, K. Faegri, P. Schwerdtfeger, Angew. Chem. Int. Ed. 1998, 37, 2493 – 2496. 3. (a) S. Inoue, C. Eisenhut, J. Am. Chem. Soc. 2013, 135, 18315−18318. (b) H. Cui, Y. Shao, C Cui, Organometallics, 2009, 28, 5191 – 5195. (c) R. Ghadwal, H. Roesky, S. Merkel, Angew. Chem., Int. Ed. 2009, 48, 5683 – 5686 (d) S. Sen, H. Roesky, D. Stern, J. Henn, D. Stalke, J. Am. Chem. Soc, 2010, 132, 1123–1126. 4. (a) T. Sasamori, N. Tokitoh, J. Am. Chem.Soc, 2008, 130, 13856–13857. (b) A. Fukazawa, S. Yamaguchi, K. Tamao, J. Am. Chem. Soc., 2007, 129, 14164–14165. (c) A. Sekiguchi, R. Kinjo, M. Ichinohe, Science, 2007, 305, 1755 – 1757.
P41 CAC vs. ACC (A= S, Se, Te, BOMe, SnMe2, PR; R = Cl, Ph, Cy) bridged bimetallics
Kassetra von Nessi,1 R. Manzano,1 A. Colebatch,1 Y.-S. Han,1 A. Hill,1 R. Shang,1 M. Sharma,1 J. Ward1 1Research School of Chemistry, Australian National University, Canberra, Australian Capital Territory, Australia, [email protected]
The possibility of bridging two metal carbyne complexes by a heteroatomic bridge (A = S, Se, Te, BOMe, SnMe2, PR; R = Cl, Ph, Cy) has been explored by exploiting the readily available lithio and halo carbyne complexes 1 [M(CX)(CO)2(Tp*)] (M = Mo, W; X= Li, Br; Tp* = hydrotris(dimethylpyrazolyl)borate). The reaction of
[Mo(CLi)(CO)2(Tp*)] with Cl2B(OMe) affords the bimetallic bis(carbyne) complex MeOB{CMo(CO)2(Tp*)}2.
In a similar manner reactions with dihalophosphines afford RP{CMo(CO)2(Tp*)}2 (R = Cl, Ph, Cy) which may also be obtained via the palladium mediated reaction of [W(CBr)(CO)2(Tp*)] with primarily phosphines (R = Cy, Ph) however these rearrange either spontaneously (R = Cl) or under forcing conditions (R = Cy, Ph) to provide phospha-acyl isomers (Tp*)(CO)2W(R)PC-CW(CO)2(Tp*).
The tellurium-bridged bis(carbyne) Te{CW(CO)2(Tp*)}2 may be isolated from the reaction of
[W(CBr)(CO)2(Tp*)] with Li2Te or of isolated [Et4N][W(CTe)(CO)2(Tp*)] with a further equivalent of 2 [W(CBr)(CO)2(Tp*)] and is stable at room temperature. In contrast, the reaction of [Mo(CBr)(CO)2(Tp*)] with
Li2S affords an intermediate, presumably S{CMo(CO)2(Tp*)}2, that spontaneously rearranges to the thioxoethenylidene complex (Tp*)(CO)2MoSCCMo(CO)2(Tp*).
The preference for bis(carbyne) MCACM vs heteroacyl MACCM connectivities has been explored computationally.
References: 1. L. M. Caldwell, A. F. Hill, R. Stranger, R. N. L. Terrett, K. M. von Nessi, J. S. Ward, A. C. Willis, Organometallics 2015, 34, 328-334.
2. A. F. Hill, R. A. Manzano, M. Sharma, J. S. Ward, Organometallics 2015, 34, 361-365.
P42 Reduced Group 2 Diiminopyridine Complexes: Synthesis, Structure and 2-Electron
Reactivity
Mike Dawkins, Cameron Jones* School of Chemistry, Monash University, Melbourne VIC 3800 [email protected], [email protected]
Diiminopyridine ligands (dimpy) are able to adopt multiple states of reduction (Figure 1). Reduced first row transition metal diiminopyridine complexes have been extensively studied, with the ligand imbuing +2/-2 redox- based reactivity to the complexes. For example, an iron(0) complex supported by a diiminopyridine is able to efficiently catalyse (0.3 mol%) the hydosilylation of alkynes via the formation of a metallocyclopropene intermediates.[1]
2- R R R R R R R R R R R R N N N N N N
N N N N N N N N N N N N Ar Ar Ar Ar Ar Ar Ar Ar Ar Ar Ar Ar dimpy dimpy- dimpy2- Figure 1 – multiple oxidation states and electronic structures observed in dimpy ligands
However, only limited research has been performed on main group diiminopyridine complexes. We have recently started to study group 2 metal complexes supported by diiminopyridine ligands. The magnesium halide adduct
[dimpyMgI2] can be selectively reduced to either [dimpyMgI] or [dimpyMg.OEt2], with the ligands singly or doubly reduced respectively.
Figure 2 – Crystal structures of [dimpyMgI2], [dimpyMgI] and [dimpyMg.OEt2]
The reactivity of doubly reduced species [dimpyMg.OEt2] is currently being tested towards a wide variety of substrates. Already we observe both oxidative addition with alkyl- and arylhalides, and activation of unsaturated species such as CO2 via metal-ligand cooperation. We aim to develop novel and unprecedented catalytic activity with this and other related systems.
References: 1. Bart, S. C. Lobkovsky, E. Chirik, P. J. J. Am. Chem. Soc. 2004, 126, 13794
2. Berben, L. A. Chem. Eur. J., 2015, 21, 2734
P43 Photophysical and photochemical investigation of tricarbonyl rhenium(I) diimine and
N-heterocyclic carbene complexes
Nurshadrina Akabar1, Kimiko Uda1, Garry Hanan2 and Max Massi1 1Department of Chemistry, Curtin University, Perth, Australia; [email protected] 2 Department de Chimie, Universite de Montreal, Quebec, Canada
The awareness that carbon monoxide (CO) plays an important role in anti-inflammatory and vasoregulatory pathways has increased in recent years. This has prompted research in the synthesis of CO-releasing molecules (CORMs). There have been several metal carbonyls capable of delivering low doses of CO to cellular targets.1 Because many of these complexes release CO upon irradiation of light, researchers have recently started to explore the possibility of “controlling” this CO release by use of UV or visible light. The interest of such photoCORMs has shifted from homoleptic metal-carbonyl complexes to more biocompatible transition metal carbonyl complexes. Rhenium(I) tricarbonyl polypyridyl complexes have shown to have rich photophysics and photochemistry which make them good candidates for the development of photoCORMs. The main advantage is that their properties can be readily tuned by the variation of their metal centres and/or ancillary ligands. They have also been used in cellular diagnostic and optical imaging. Until recently, rhenium(I) N-heterocyclic carbenes have been shown to be photoactive and can release CO.2,3 However the detailed mechanism has still not been fully elucidated. To increase our knowledge on the photoreactivity of rhenium(I)-based photoCORMs, a series of cationic and neutral rhenium(I) tricarbonyl complexes were synthesised with varying ancillary ligands. Spectroscopic and photophysical characterisation were carried out to understand their properties.
Acknowledgements: The author would like to thank Curtin University for the provision of an APA scholarship and the ARC for funding.
References: 1. B. Mann, Organometallics, 2012, 31, 5728. 2. L. Casson, S. Muzzioli, P. Raiteri, B. W. Skelton, S. Stagni, M. Massi and D. H. Brown, Dalton Trans., 2011, 40, 11960. 3. J. G. Vaughan, B. L. Reid, S. Ramchandani, P. J. Wright, S. Muzzioli, B. W. Skelton, P. Raiteri, D. H. Brown, S. Stagni and M. Massi, Dalton Trans., 2013, 42, 14100.
P44 The divergent application of three-membered strained-ring systems in the palladium-
catalysed ring-opening reaction
Yin Jie Xiang,1 Christopher Hyland 2 [email protected], School of Chemistry, University of Wollongong 2 [email protected]
Abstract: The chemistry of three-membered ring heterocycles has drawn intense interest in organic synthesis over decades. Many reactions that exhibit the reactivity of three-membered ring systems were discovered.1 Among these reactions, those catalysed by organotransition-metal represent a range of conceptually novel and immensely practical approaches that allow the access to the synthesis of complex molecules possessing biological activity. For example, an alkyl reductive cross-coupling reactions was developed by the Jamison group to construct 2 homoallylic alcohol using expoides in the presence of Ni(cod)2 and PBu3. Also, alkyl aziridines were also successfully coupled with boronic acids in the presence of a palladium catalytic system and phenol additive. The regioselective arylation , which occurs at less sterically hindered position, was achieved in this reaction under mild conditions.3 In addition, a rare example of nucleophilic attack has recently been reported by Plietker and co- workers, where they show nucleophilic ferrate Bu4N[Fe-(CO)3(NO)] (TBAFe) is able to generate an allyl-Fe intermediate via ring-opening of vinylcyclopropanes, and the intermediate is then subject to attack by soft carbonucleophiles, such as malonates.4 In our research, the strained-ring systems including vinylcyclopropane, phenyl- and vinylaziridine were utilised to undergo ring-opening reaction under the catalysis of organotransition- metal. The palladium(II)-catalysed addition of arylboronic acids to vinylaziridines has been first developed. This reaction proceeds via an insertion/ring-opening process to provide unusual (Z)-allylsulfonamides preferentially.5 Moreover, the C3-substitution of indole derivative was successfully performed with arylaziridines in the presence of lewis acids via Friedel-Crafts reaction. In addition, a highly efficient ring-opening reaction of vinylcyclopropanes by boronic acids in water was reported, using palladium nanoparticles formed from Pd(OAc)2 in net water. Linear and branched regioselectivities were obtained using vinylcyclopropanes and substituted vinylcyclopropanes respectively under the ligandless condition.6
Acknowledgements: The University of Wollongong is acknowledged for generous support of this research. J. X. thanks the University of Wollongong for IPTA and UPA scholarships. References: 1. Doyle, A. G.; Huang, C. Y., Chem. Rev. 2014, 114, 8153−8198. 2. Molinaro, C.; Jamison, T. F., J. Am. Chem. Soc. 2003, 125, 8076. 3. Duda, M. L.; Michael, F. E., J. Am. Chem. Soc. 2013, 135, 18347. 4. Dieskau, A. P.; Holzwarth, M. S.; Plietker, B. J. Am. Chem. Soc. 2012, 134, 5048–5051. 5. Yin, J. X.; Mekelburg, T.; Hyland, C., Org. Biomol. Chem., 2014, 12, 9113-9115. 6. Yin, J. X.; Hyland, C., J. Org. Chem., 2015, 80, 6529–6536.
P45 Ir(III)-1,2,4 triazole donor and Lanthanide acceptor for electrochemically sensitized luminescence
Linh M Quan, Bradley D. Stringer, Conor F. Hogan, Peter J. Barnard Department of Chemistry and Physics, LIMS - La Trobe University, Bundoora VIC 3083, Australia. Email: [email protected]
Lanthanides have been extensively studied for their near-infrared emission, however highly absorbing organic ‘antenna’ groups are generally required to allow efficient excitation of the metal ion.1 Transition metal complexes offer several desirable properties for use as ‘antenna’ groups, when compared to conventional organic chromophores. These include: long luminescent lifetimes, high quantum yields, large Stokes shift and high chemical and photochemical stability.1 The macrocyclic ligand: DOTA, 1, 4, 7, 10-tetraazaccyclododecane- 1,4,7,10-tetraacetic acid, is well known for its high affinity for lanthanide ions. This ligand has been used to construct a d-f heterobimetallic array with a highly luminescent Ir(III) complex of a 1, 2, 4 triazole ligand.2 An amine functionalized of a Ir(III) complex 1,2,4 triazole ligand was conjugated to DOTA by amide bond formation. The electrochemical and photophysical properties of the Ir(III) complexes and preliminary photophysical titration studies with Nd3+ and Eu3+ ions will be reported.
Figure 1: Structure of d-f heterobimetallic array.
References: (1) Sykes, D.; Cankut, A. J.; Ali, N. M.; Stephenson, A.; Spall, S. J. P.; Parker, S. C.; Weinstein, J. A.; Ward, M. D. Dalton Trans. 2014, 43, 6414. (2) Ward, M. D. Coord. Chem. Rev. 2007, 251, 1663.
OZOM IX PROGRAM
Tuesday Wednesday Thursday Friday 8 December 9 December 10 December 11 December Welcome 8.50-9.00 9:00 OL26 M. Hossain 9.00-9.20 PL1 F. E. Hahn 9.00-10.00 PL3 J. Weigand 9.00-10.00 OL27 E. Border 9.20-9.40 OL28 T. Wierenga 9.40-10.00 10:00 OL1 N. Camasso 10.00-10.20 OL12 S. Binding 10.00-10.20 OL29 Y.-S. Han 10.00-10.20 OL2 S. Scottwell 10.20-10.40 OL13 T. Nicholls 10.20-10.40 OL30 C. Hyland 10.20-10.40
11:00 morning tea morning tea morning tea OL3 S. Ali 11.10-11.30 OL14 T. Hadlington 11.10-11.30 PL4 R. Kempe 11.10-12.10 OL4 T. Field-Theodore 11.30-11.50 OL15 P. Simpson 11.30-11.50 12:00 OL5 L. Abad Galán 11.50-12.10 OL16 M. Roemer 11.50-12.10 OL6 D. Twycross 12.10-12.30 OL17 A. Nair 12.10-12.30 Student poster/oral prize awards and Conference close 13:00 LUNCH LUNCH Closing drinks
14:00 OL18 Ke. Gloe 13.50-14.10 PL2 A. Stasch 13.50-14.50 OL19 C. Ma 14.10-14.30 OL20 Y. Ong 14.30-14.50 afternoon tea 15:00 afternoon tea
OL7 A. Triadon 15.20-15.40 OL21 Ka. Gloe 15.20-15.40 16:00 OL8 J.-S. Huang 15.40-16.00 OL22 M. Kodikara 15.40-16.00 OL9 P. Jurd 16.00-16.20 OL23 C. Wong 16.00-16.20 OL10 A. Davey 16.20-16.40 OL24 M. Morshedi 16.20-16.40 OL11 E. Clatworthy 16.40-17.00 OL25 J. Markham 16.40-17.00 17:00
Poster session Poster session Registration (The Grandstand) 18:00 17.00-18.30 17.00-18.30 17:30-18.30
19:00 Opening mixer (The Grandstand) Conference dinner (Thai Pothong, Newtown) 20:00 18.30-20.30 19:00 until late
VENUES: All talks in the St Andrew's College Chapel. Poster session and teas in St. Andrew's Common Room. Opening mixer in The Grandstand.