DOCSLIB.ORG

Spin Modulation and Electrochemical Behavior of a Five-Coordinate Cobalt(III) Salen Complex

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Spin Modulation and Electrochemical Behavior of a Five-Coordinate Cobalt(III) Salen Complex Journal of Coordination Chemistry ISSN: 0095-8972 (Print) 1029-0389 (Online) Journal homepage: http://www.tandfonline.com/loi/gcoo20 Spin modulation and electrochemical behavior of a five-coordinate cobalt(III) salen complex James R. Buchwald, Subhadeep Kal, Marissa R. Civic, Ian M. deJoode, Alexander S. Filatov & Peter H. Dinolfo To cite this article: James R. Buchwald, Subhadeep Kal, Marissa R. Civic, Ian M. deJoode, Alexander S. Filatov & Peter H. Dinolfo (2016): Spin modulation and electrochemical behavior of a five-coordinate cobalt(III) salen complex, Journal of Coordination Chemistry, DOI: 10.1080/00958972.2016.1175001 To link to this article: http://dx.doi.org/10.1080/00958972.2016.1175001 View supplementary material Accepted author version posted online: 07 Apr 2016. Published online: 28 Apr 2016. Submit your article to this journal Article views: 10 View related articles View Crossmark data Full Terms & Conditions of access and use can be found at http://www.tandfonline.com/action/journalInformation?journalCode=gcoo20 Download by: [Rensselaer Polytechnic Institute] Date: 06 May 2016, At: 08:36 JOURNAL OF COORDINATION CHEMISTRY, 2016 http://dx.doi.org/10.1080/00958972.2016.1175001 Spin modulation and electrochemical behavior of a five- coordinate cobalt(III) salen complex James R. Buchwalda , Subhadeep Kala , Marissa R. Civica , Ian M. deJoodea, Alexander S. Filatovb,c and Peter H. Dinolfoa aDepartment of Chemistry and Chemical Biology, Rensselaer Polytechnic Institute, Troy, NY, USA; bDepartment of Chemistry, University at Albany, State University of New York, Albany, NY, USA; cDepartment of Chemistry, University of Chicago, Chicago, IL, USA ABSTRACT ARTICLE HISTORY We report the synthesis of a Co(III) complex with the five-coordinate salen- Received 22 January 2016 type ligand (N,N′-bis(3,5-di-tert-butyl-2-hydroxybenzyliden)-1,7-diamino-4- Accepted 23 March 2016 methyl-4-azaheptane). This complex is stable in air with a trigonal bipyramidal geometry and we show spectroscopically and computationally that a high- KEYWORDS Salen; spin modulation; spin triplet ground state is preferred. This spin state is readily modulated electron transfer; spin by introduction of an exogenous ligand (pyridine, acetonitrile) to yield a crossover; mixed-valence six-coordinate complex with low-spin ground state. The five-coordinate complex exhibits solvent- and ligand-dependent electrochemical behavior in solution for the CoII/III transition and undergoes a one-electron ligand oxidation to generate a phenoxyl radical species that is relatively stable in the absence of oxygen. We show that this phenoxyl radical species is a Class I mixed-valence compound that can undergo photoinduced inner-sphere charge transfer with the neighboring phenoxide. This process is mediated by the Co(III) center which acts as a bridge. Understanding this behavior will lead to a better understanding of a dicobalt bis-salen analog previously reported by our group as a proton reduction catalyst. Downloaded by [Rensselaer Polytechnic Institute] at 08:36 06 May 2016 1. Introduction Salen complexes of transition metals are classic examples of macrocyclic coordination complexes. Perhaps the most famous of this family of molecules is Jacobsen’s catalyst, a tetradentate salen ligand coordinated to a manganese(II), which is widely used for the asymmetric epoxidation of alkenes [1–3]. CONTACT Peter H. Dinolfo [email protected] Supplemental data for this article can be accessed at http://dx.doi.org/10.1080/00958972.2016.1175001. © 2016 Informa UK Limited, trading as Taylor & Francis Group 2 J. R. BuchwaLD ET AL. Salen complexes have found a wide range of applications in chemistry including catalysis [4], molecular magnetism [5, 6], and the preparation of nanostructured thin films [7]. Transition metal salen complexes have also been employed as biomimetic models to study the spectroscopic properties of enzyme active sites. A distinguishing feature of the salen ligand is the redox activity of the two phenolate moieties in the backbone. These groups are known to actively participate in oxidative chemistry alongside the metal center in analogous complexes containing Cu, Zn, and Ni metal centers [8]. Complexes of this type provide an excellent model for biochemical phenomena such as the CuII-tyrosyl radical found in galactose oxidase [9]. This “guilty ligand” behavior can also have significant consequences for any catalytic behavior of these complexes. Cobalt salens were first studied as early as 1938 when the “salcomine” complex, a square planar cobalt(II) complex, was reported to reversibly bind molecular oxygen [10]. This early example was based on a simple tetradentate ligand formed through condensation of salicylaldehyde with ethylenediamine. In 1946, Roberts and colleagues systematically varied the nitrogen-bearing “backbone” of the salen ligand with the goal of tuning the oxygen-binding properties of salcomine-like complexes [11]. This research eventually led Van Dort and Geursen in 1967 to discover that oxygen-bound cobalt salens could catalytically oxidize phenols to quinones [12]. Similarly, the cobalt analog of Jacobsen’s catalyst [1] was reported in 1999 to catalyze the enantioselective ring-opening of epoxides [13]. Our research group first became interested in the properties of first-row transition metal salens due to their similarity to the bis-salen architectures (M2BisSalen in scheme 1) we have employed as water oxidation and proton reduction catalysts [14–17]. Bis-salens feature a similar ligand architecture, again containing two redox-active phenolate moieties, but coordinate two transition metals through the introduction of an additional pair of Schiff bases ortho to the phenolic oxygen. The electrochemical and spectroscopic properties of these molecules can be complicated by strong electronic correlation between the two transition metals. Salen complexes are thus a natural choice of system in which to examine the interplay of ligand and metal electronic properties in the absence of strong correlation effects. In this paper, we report an unusual behavior of the ground-state electronic structure of a stable pentadentate cobalt(III) salen, CoL+. This five-coordinate trigonal bipyramidal complex, in contrast to the widely studied four-coordinate cobalt salens described above, leaves only one coordination site open and accessible on CoIII. We demonstrate that the coordination of one pyridine ligand to give the tetragonal complex CoLPy+ induces a drastic change in the spin state of the cobalt. This has a pro- nounced effect on the redox properties and electronic spectra of the complex. We characterize this Downloaded by [Rensselaer Polytechnic Institute] at 08:36 06 May 2016 + + Scheme 1. Schematic representation of M2BisSalen, CoL , and CoLPy . JOURNAL OF Coordination CHEMISTRY 3 unusual behavior using electronic absorbance spectra, electrochemical techniques, paramagnetic NMR studies, and density functional theory (DFT) calculations. 2. Results and discussion 2.1. Synthesis H2L (N,N′-bis(3,5-di-tert-butyl-2-hydroxybenzyliden)-1,7-diamino-4-methyl-4-azaheptane) was syn- thesized via a Schiff base condensation reaction between 3,3′-diamino-N-methyldipropylamine and 3,5-di-tert-butyl-2-hydroxybenzaldehyde in refluxing ethanol [8]. Addition of Co(ClO4)2 to a solution of H2L in refluxing ethanol under nitrogen yieldedCoL . This was subsequently oxidized with AgSbF6 in anhydrous dichloromethane with and without pyridine to obtain CoL+ and CoLPy+, respectively, as − the SbF6 salts. These compounds were confirmed by elemental analysis, mass spectrometry, Fourier 1 transform infrared spectroscopy (FTIR), H NMR, and UV–visible spectroscopy. The FTIR spectra of H2L, CoL, CoL+, and CoLPy+ are shown in figure S1. 2.2. X-ray crystal structure The X-ray crystal structures of CoL+ (CCDC No. 1447916) and CoLPy+ (CCDC No. 1447917) are shown in figure 1. Table 1 includes crystallographic data and structural refinement parameters, and table 2 contains selected bond lengths and angles. The structure of CoL+ is closely related to that of CoL’ reported by Boča et al., where L’ is N,N′-bis(3-tert-butyl-5-methyl-2-hydroxybenzyliden)-1,7-diamino- 4-methyl-4-azaheptane [18] (relevant data are also included in table 2) and ML type complexes for M = Zn(II), Ni(II), and Cu(II) [8]. The N-methyldipropylamine backbone enforces a butterfly-like structure of the salen ligand framework and trans-coordination of the Nimines to Co. There is some disorder in the N-methyldipropylamine backbone with respect to the position of the N-methyl group and one of the t-butyl groups. CoL+ assumes a slightly distorted trigonal bipyramidal geometry around Co with the two imine nitrogens (N1 and N3) occupying the axial positions and forming a 178.95° bond angle (N1– Co1–N3). The Ophenolates (O1 and O2) and the Namine (N2) occupy the equatorial positions with respect to Co1. The O1–Co1–O2 bond angle (129.39°) is slightly larger than the other two equatorial bond angles (i.e. O1–Co1–N3 and O2–Co1–N3) at 115.41 and 115.49°, respectively, leading to the distortion. Downloaded by [Rensselaer Polytechnic Institute] at 08:36 06 May 2016 Figure 1. Side and top view ORTEP diagrams of (a) [CoL](SbF6) and (b) [CoLPy](SbF6)·(CH2Cl2)0.5 showing 50% probability thermal ellipsoids. Non-coordinating anion, hydrogen, and solvent atoms are omitted for clarity. 4 J. R. BuchwaLD ET AL. Table 1. Crystallographic data and structural refinement parameters for [CoL](SbF6) and [CoLPy](SbF6)·(CH2Cl2)0.5. [CoL](SbF6) [CoLPy](SbF6)·(CH2Cl2)0.5 Formula C37H57F6CoN3O2Sb C42H62F6CoN4O2Sb fw 870.54 992.10 Crystal system Monoclinic Triclinic Space group C2/c P1̄ a (Å) 31.836(6) 11.8859(9) b (Å) 11.966(2) 13.6004(10) c (Å) 21.062(4) 14.3193(11) α (°) 90 92.6110(10) β (°) 99.122(2) 92.9470(10) γ (°) 90 103.0650(10) V (Å3) 7923(2) 2248.0(3) Z 8 2 T (K) 100(2) 100(2) λ (Å) 0.71073 0.71073 ρ (calcd, g cm−3) 1.46 1.466 μ (mm−1) 1.164 1.093 Reflections collected 9336 10,135 No.
Load more

Recommended publications
  • Redalyc.Immobilization of Jacobsen Type Catalysts on Modified Silica
    Revista Facultad de Ingeniería Universidad de Antioquia ISSN: 0120-6230 [email protected] Universidad de Antioquia Colombia Cubillos, Jairo; Grajales, Edwing; Vásquez, Santiago; Montes de Correa, Consuelo Immobilization of Jacobsen type catalysts on modified silica Revista Facultad de Ingeniería Universidad de Antioquia, núm. 57, enero, 2011, pp. 38-48 Universidad de Antioquia Medellín, Colombia Available in: http://www.redalyc.org/articulo.oa?id=43021212005 How to cite Complete issue Scientific Information System More information about this article Network of Scientific Journals from Latin America, the Caribbean, Spain and Portugal Journal's homepage in redalyc.org Non-profit academic project, developed under the open access initiative Rev. Fac. Ing. Univ. Antioquia N.° 57 pp. 38-48. Enero, 2011 Immobilization of Jacobsen type catalysts on modified silica Inmovilización de catalizadores tipo Jacobsen en sílica modificada Jairo Cubillos1*, Edwing Grajales2, Santiago Vásquez2, Consuelo Montes de Correa2 1Escuela de Ciencias Químicas, Facultad de Ciencias, Universidad Pedagógica y Tecnológica de Colombia-UPTC. Avenida Central del Norte- Tunja, Boyacá, Colombia. 2Grupo Catálisis Ambiental, Facultad de Ingeniería, Universidad de Antioquia, Apartado Aéreo 1226, Medellín, Colombia (Recibido el 26 de enero de 2010. Aceptado el 15 de octubre de 2010) Abstract Several immobilized Jacobsen type catalysts were covalently anchored on modified SiO2 using 3-aminopropyltriethoxysilane (3-APTES) as a reactive surface modifier. Characterization of the heterogeneous catalysts, as well as their precursors, by FTIR, DR UV–VIS, TGA and AAS confirms the successful immobilization of chiral Mn(III) salen complexes. These catalysts were examined for the diastereoselective epoxidation of R-(+)-limonene with in situ generated dimethyldioxirane (DMD) as oxidizing agent, yielding 1,2-epoxide as the main product.
    [Show full text]
  • Page 1 of 35 Dalton Transactions
    Dalton Transactions Accepted Manuscript This is an Accepted Manuscript, which has been through the Royal Society of Chemistry peer review process and has been accepted for publication. Accepted Manuscripts are published online shortly after acceptance, before technical editing, formatting and proof reading. Using this free service, authors can make their results available to the community, in citable form, before we publish the edited article. We will replace this Accepted Manuscript with the edited and formatted Advance Article as soon as it is available. You can find more information about Accepted Manuscripts in the Information for Authors. Please note that technical editing may introduce minor changes to the text and/or graphics, which may alter content. The journal’s standard Terms & Conditions and the Ethical guidelines still apply. In no event shall the Royal Society of Chemistry be held responsible for any errors or omissions in this Accepted Manuscript or any consequences arising from the use of any information it contains. www.rsc.org/dalton Page 1 of 35 Dalton Transactions Synthesis and aggregation behaviour of luminescent mesomorphic zinc(II) complexes with ‘salen’ type asymmetric Schiff base ligand Sutapa Chakraborty, a Chira R. Bhattacharjee,* a Paritosh Mondal, a S. Krishna Prasad, b and D. S. Shankar Rao b a Department of Chemistry, Assam University, Silchar 788011, Assam, India. b Centre for Nano and Soft Matter Sciences, Jalahalli, Bangalore 560013, India. * Corresponding author. Tel.: +91-03842-270848; fax: +91-03842-270342 Email: [email protected] Manuscript Accepted Transactions Dalton 1 Dalton Transactions Page 2 of 35 Table of Contents Synthesis and aggregation behaviour of luminescent mesomorphic zinc(II) complexes with ‘salen’ type asymmetric Schiff base ligand Sutapa Chakraborty, a Chira R.
    [Show full text]
  • DETECTION of SALEN-TYPE TRACERS for SUBTERRANEAN FLUID FLOW MONITORING USING SURFACE- ENHANCED RAMAN SPECTROSCOPY Jenny C
    University of New Mexico UNM Digital Repository Chemistry ETDs Electronic Theses and Dissertations Spring 5-12-2018 DETECTION OF SALEN-TYPE TRACERS FOR SUBTERRANEAN FLUID FLOW MONITORING USING SURFACE- ENHANCED RAMAN SPECTROSCOPY Jenny C. Sanchez University of New Mexico Follow this and additional works at: https://digitalrepository.unm.edu/chem_etds Part of the Inorganic Chemistry Commons, and the Physical Chemistry Commons Recommended Citation Sanchez, Jenny C.. "DETECTION OF SALEN-TYPE TRACERS FOR SUBTERRANEAN FLUID FLOW MONITORING USING SURFACE-ENHANCED RAMAN SPECTROSCOPY." (2018). https://digitalrepository.unm.edu/chem_etds/88 This Thesis is brought to you for free and open access by the Electronic Theses and Dissertations at UNM Digital Repository. It has been accepted for inclusion in Chemistry ETDs by an authorized administrator of UNM Digital Repository. For more information, please contact [email protected]. Jenny C. Sanchez Candidate Chemistry and Chemical Biology Department This thesis is approved, and it is acceptable in quality and form for publication: Approved by the Thesis Committee: Richard A. Kemp, Chairperson Terefe G. Habteyes Ramesh Giri i DETECTION OF SALEN-TYPE TRACERS FOR SUBTERRANEAN FLUID FLOW MONITORING USING SURFACE-ENHANCED RAMAN SPECTROSCOPY by JENNY C. SANCHEZ B.S., NEW MEXICO STATE UNIVERSITY, 2004 THESIS Submitted in Partial Fulfillment of the Requirements for the Degree of Master of Science Chemistry The University of New Mexico Albuquerque, New Mexico May, 2018 ii DEDICATION This work is lovingly dedicated to my little sister, Vivian. iii ACKNOWLEDGEMENTS I gratefully acknowledge my co-advisors, Dr. Richard Kemp and Dr. Terefe Habteyes, for their support and patience during my time working on this research project.
    [Show full text]
  • The Preparation and Use of Metal Salen Complexes Derived from Cyclobutane Diamine
    THE PREPARATION AND USE OF METAL SALEN COMPLEXES DERIVED FROM CYCLOBUTANE DIAMINE by SMITA S. PATIL B. Tech., University of Mumbai, 2005 M. Tech., University of Mumbai, 2007 AN ABSTRACT OF A DISSERTATION Submitted in partial fulfillment of the requirements for the degree DOCTOR OF PHILOSOPHY Department of Chemistry College of Arts and Sciences KANSAS STATE UNIVERSITY Manhattan, Kansas 2014 Abstract The helix is an important chiral motif in nature, there is increasing development in field of helical transition metal complexes and related supramolecular structures. Hence, the goals of this work are to apply the principles of helicity in order to produce metal complexes with predictable molecular shapes and to study their properties as asymmetric catalysts. Computational studies suggest that the (1R,2R)-cyclobutyldiamine unit can produce highly twisted salen complexes with a large energy barrier between the M and P helical forms. To test this prediction, the tartrate salt of (1R,2R)-cyclobutyldiamine was synthesized and condensed with a series of saliclaldehydes to produce novel salen ligands. The salicylaldehydes chosen have extended phenanthryl or benz[a]anthryl sidearms to encourage formation of helical coordination complexes. These ligands were metallated with zinc, iron and manganese salts to produce salen metal complexes which were characterized by NMR analysis, high-resolution mass spectrometry, and IR spectroscopy. A second ligand type, neutral bis(pyridine-imine) has also been synthesized from (1R,2R)-cyclobutyldiamine and quinolylaldehydes. The synthesis of bis(pyridine-imine) ligands was conducted using greener method, solvent assisted grinding. These ligands, in-situ with nickel metal salts, showed good catalytic activity for asymmetric Diels-Alder reactions.
    [Show full text]
  • SFU Thesis Template Files
    Elucidating the Electronic Structure of Transition Metal Complexes Featuring Redox Active Ligands by Linus Chiang B.Sc., Simon Fraser University, 2009 Thesis Submitted in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy in the Department of Chemistry Faculty of Science Linus Chiang 2014 SIMON FRASER UNIVERSITY Fall 2014 Approval Name: Linus Chiang Degree: Doctor of Philosophy (Chemistry) Title: Elucidating the Electronic Structure of Transition Metal Complexes Featuring Redox Active Ligands Examining Committee: Chair: Hogan (Hua-Zhong) Yu Professor Tim Storr Senior Supervisor Associate Professor Daniel B. Leznoff Supervisor Professor Peter D. Wilson Supervisor Associate Professor Jeffrey J. Warren Internal Examiner Assistant Professor Alan F. Heyduk External Examiner Associate Professor Chemistry School of Physical Sciences University of California Irvine Date Defended/Approved: October 30th, 2014 ii Partial Copyright Licence iii Abstract In this thesis a number of projects involving the design and characterization of complexes bearing redox active ligands are described. Focusing on the phenolate containing ligands, the properties and electronic structure of their corresponding metal complexes were studied by a series of experimental (i.e. electrochemistry, UV-Vis-NIR, EPR, rR etc.) and theoretical (DFT) methods. Specifically, the redox processes of these metal complexes were tuned by varying the para-ring substituents. In one study, nickel- salen (salen is a common abbreviation for N2O2 bis-Schiff-base bis-phenolate ligands) complexes were investigated, where the oxidation potentials of the ligand were predictably decreased as the electron donating ability of the para-ring substituents was increased (NMe2 > OMe > tBu > CF3). Interestingly, the oxidation of these geometrically-symmetric complexes afforded an asymmetric electronic structure in a number of cases, in which the ligand radical was localized on one phenolate rather than delocalized across the ligand framework.
    [Show full text]
  • Metal-Salen-Based Probes for the Selective Detection of Phosphates<I>
    252 CHIMIA 2020, 74, No. 4 LAUREATES: JUNIOR PRIZES OF THE SCS FALL MEETING 2019 doi:10.2533/chimia.2020.252 Chimia 74 (2020) 252–256 © P. Yadav, F. Zelder Metal-Salen-based Probes for the Selective Detection of Phosphates via a Disassembly Approach Prerna Yadav§ and Felix Zelder* §SCS-DSM Award for best poster presentation in Analytical Sciences Abstract: Polyoxophosphates are ubiquitous in nature and play important roles in biological systems and in the environment. Pyrophosphate (PPi), an important member of this family, is produced in over 200 biochemical reactions and is a marker in clinical diagnosis. In addition to its endogenous role, PPi alias E450 is currently used as preservative, emulsifier or taste intensifier in foodstuff. Despite this widespread occurrence and biologi- cal importance, it is rather surprising that robust chemical systems that detect selectively and sensitively PPi in challenging matrices are still lacking. This mini review focuses on metal-salen complexes as reaction-based fluorescent sensors for the selective detection of PPi and other phosphates. The mode of detection is based on a novel disassembly approach in which the metal ion is sequestered by the target analyte from the complex and the metal-free ligand hydrolyses spontaneously into its fluorescent subunits. Optimizations of the probe and applications for PPi detection in cells and foodstuff are described. Keywords: Cell studies · Disassembly approach · Foodstuff · Phosphates · Salen complex Prerna Yadav was born in Madhya Pradesh NH2 O O in India. She moved to National Institute of N N O O P O O Science Education and Research (NISER) P P O O O N N O in Odisha, to the East of India for her O O O O P O P O P O O O P O O P O Integrated Master’s degree programme.
    [Show full text]
  • Transition Metal Chelates with Schiff Bases Derived from Salicylaldehyde
    I TRANSITION METAT CHETATES \ryITH SCHIFF BASES DERIVED FROM SATICYTATDEHYDE AND DIAMINO ETHANE ALVIN PAUL SUMMERTON, a.sc. UNIVERSITY OF ADELAIDE, DEPARTMENT OF PHYSICAL AND INORGANIC CHEMISTRY November 1978 1tu¡artol q''-'t tÇ14 Pl.l CONTENTS Page SUMII{ARY STATEMENT ACKNOhTLEDGEMENTS ABBREVIATIONS CHAPTER 1: Introduction t PART Ï CHAPTER 2: Preparation and characterization of salen complexes of iron (III) 6 CHAPTER 3: Solut.ion studies 30 CHAPTER 4: Moessbauer .spectra 57 PART II CHAPTER 5: Preparation, characterization and solid state properties 84 CHAPTER 6: Solution studies 115 CHAPTER 7: Crystal structure of Fe (saen) 2C1-.H2O 143 APPENDTX I: Computer Programs APPENDÏX II: Structure Factor Tables APPENDTX III: Publication BIBLTOGRAPHY SUM¡{ARY The following study of transition metal complexes with Schiff base ligands comprises two related studies. PART I Complexes of the quadridentate ligand, sa1en. A number of complexes of general formula Fe(III)salenX, where X = Cl, Br, I, NO3, N3, NCS and C6H5COO, have been pre- pared. Of these species, two (X = NO3 and N3) have not been previously reported and only one (X = Cl) has been intensively studied. In addition, two novel octahedral complex salts KlFesalen(CN)21 and Fe(saen) 2C1-.H2O, which involve a low spin central metal ion, have been obtained. The salt Fe(saen) 2CI. H2O has several unusual properties which have been examined in Part II of this thesis. This j-nvestigation of the salen complexes has involved: (1) confirmation of structure by microanalysis, i.r. spectra and magnetism; (2\ a sÈudy of the u.v.-visible solution spectra; (3) deterinination of the Moessbauer spect.ral parameters.
    [Show full text]
  • Nouvelles Sondes Électrochimiques Pour Le Marquage De Biocapteurs D’Affinité Amani Ben Jrad
    Nouvelles sondes électrochimiques pour le marquage de biocapteurs d’affinité Amani Ben Jrad To cite this version: Amani Ben Jrad. Nouvelles sondes électrochimiques pour le marquage de biocapteurs d’affinité. Autre. Université de Perpignan, 2019. Français. NNT : 2019PERP0038. tel-02612848 HAL Id: tel-02612848 https://tel.archives-ouvertes.fr/tel-02612848 Submitted on 19 May 2020 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. [Tapez une citation prise dans le document ou la synthèse d'un passage Délivré par intéressant. Vous pouvez placer la zone de texte n'importe où dans le UNIVERSITE DE PERPIGNAN VIA DOMITIA document. Utilisez l'onglet Outils de zone de texte pour modifier la mise en forme de la zone de texte de la citation.] Préparée au sein de l’école doctorale ED 305 Et de l’unité de recherche LBBM - BAE Spécialité : Chimie Présentée par Mme Amani BEN JRAD NOUVELLES SONDES ELECTROCHIMIQUES POUR LE MARQUAGE DE BIOCAPTEURS D’AFFINITE Soutenue le 13 décembre 2019 devant le jury composé de M. Pierre GROS, Pr, LGC - Université Paul Sabatier Rapporteur M. François MORVAN, DR INSERM, IBMM - Université de Montpellier Rapporteur Mme.
    [Show full text]
  • Bis(Salicylidene)Ethylenediamine(Salen) and Bis(Salicylidene)Ethylenediamine-Metal Complexes: from Structure to Biological Activity
    Journal of Analytical & Pharmaceutical Research Bis(Salicylidene)Ethylenediamine(Salen) and Bis(Salicylidene)Ethylenediamine-Metal Complexes: from Structure to Biological Activity Abstract Review Article Schiff bases and their metal complexes have occupied a central role in the Volume 3 Issue 6 - 2016 development of co-ordination chemistry as evidenced by the vast number, ease and flexibility of the synthetic procedure, diverse properties, and use as biologically active compounds as antitumor, antibacterial, antifungal and other miscellaneous Department of Industrial Chemistry, Ebonyi State University, biological applications. Many reports have demonstrated that Salen and Salen- Nigeria metal complexes are highly active against several diseases, including cancer. The thrust of this review work is to evaluate the structural nature of Salen and assess *Corresponding author: Felix Sunday Nworie, Department the biological applications thereof. of Industrial Chemistry, Ebonyi State University, PMB 053 Abakaliki, Ebonyi State, Nigeria, Tel: +2348034813342; Keywords: Schiff base; Salen; Metal salen; Biological applications; Structural Email: characterization Received: October 31, 2016 | Published: December 15, 2016 Abbreviations: C: Carbon; N: Nitrogen; DMSO: Dimethylsulphoxide; PXRD: Powder X-ray Diffractometer; the elimination of the hemiaminal (carbinolamine) hydroxyl SOD: Superoxide Dismutase; Cu: Copper; Zn: Zinc; Fe: Iron; groupconditions, (dehydration there is unavailabilitystep) [5]. of sufficient protons to catalyze Cr: Chromium; Mn:
    [Show full text]
  • Electronic Structure and Reactivity of Transition Metal Complexes Incorporating Pro-Radical Bis- Phenoxide Ligands
    Electronic Structure and Reactivity of Transition Metal Complexes Incorporating Pro-Radical Bis- Phenoxide Ligands by Ryan Michael Clarke B.Sc. (Hons), Mount Allison University, 2012 Thesis Submitted in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy in the Department of Chemistry Faculty of Science © Ryan Michael Clarke SIMON FRASER UNIVERSITY Spring 2018 Copyright in this work rests with the author. Please ensure that any reproduction or re-use is done in accordance with the relevant national copyright legislation. Approval Name: Ryan Michael Clarke Degree: Doctor of Philosophy (Chemistry) Title: Electronic Structure and Reactivity of Transition Metal Complexes Incorporating Pro-Radical Bis-Phenoxide Ligands Chair: Dr. Michael H. Eikerling Professor Examining Committee: Dr. Tim Storr Senior Supervisor Associate Professor Dr. Daniel B. Leznoff Supervisor Professor Dr. Vance E. Williams Supervisor Associate Professor Dr. Loren Kaake Internal Examiner Assistant Professor Dr. Andrew S. Borovik External Examiner Professor Department of Chemistry University of California, Irvine Date Defended/Approved: April 5, 2018 ii Abstract Transition metal complexes with pro-radical ligands have received considerable research attention due to their interesting electronic structures, photophysical properties, and applications in catalysis. The relative ordering of metal and ligand frontier orbitals in a complex incorporating pro-radical ligands dictates whether oxidation/reduction occurs at the metal centre or at the ligand. Many metalloenzymes couple redox events at multiple metal centres or between metals and pro-radical ligands to facilitate multielectron chemistry. Owing to the simplicity of the active sites, many structural and functional models have been studied. One class of pro-radical ligand that has been investigated extensively are bis-imine bis-phenoxide ligands (i.e.
    [Show full text]
  • Metal Salen Catalyzed Production Of
    View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by Texas A&M University METAL SALEN CATALYZED PRODUCTION OF POLYTRIMETHYLENE CARBONATE A Dissertation by POULOMI GANGULY Submitted to the Office of Graduate Studies Texas A&M University in partial fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY May 2006 Major Subject: Chemistry METAL SALEN CATALYZED PRODUCTION OF POLYTRIMETHYLENE CARBONATE A Dissertation by POULOMI GANGULY Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY Approved by: Chair of Committee, Donald J. Darensbourg Committee Members, Abraham Clearfield Francois P. Gabbaï Shankar P. Bhattacharyya Head of Department, Emile A. Schweikert May 2006 Major Subject: Chemistry iii ABSTRACT Metal Salen Catalyzed Production of Polytrimethylene Carbonate. (May 2006) Poulomi Ganguly, B.S., St. Stephen’s College; M.S., University of Delhi Chair of Advisory Committee: Dr. Donald J. Darensbourg Over the past decade the focus of our group has been production of polycarbonates through environmentally friendly routes. Continuing with this tradition, one such route is the ring opening polymerization of cyclic carbonates. The aliphatic polycarbonate derived from trimethylene carbonate, (TMC, 1, 3-dioxan-2-one), has been studied extensively for its potential use as a biodegradable polymer in biomedical and pharmaceutical systems. Its important applications include sutures, drug delivery systems and tissue engineering. To date, majority of the literature concerning catalysts for polymerization of TMC has been restricted to the use of simple Lewis acids with a marked absence of well defined and characterized catalysts.
    [Show full text]
  • Downloaded from the Protein Data Bank ( Accessed Date 21 April 2021)
    molecules Article Synthesis, DFT Calculations, Antiproliferative, Bactericidal Activity and Molecular Docking of Novel Mixed-Ligand Salen/8-Hydroxyquinoline Metal Complexes Badriah Saad Al-Farhan 1,*, Maram T. Basha 2 , Laila H. Abdel Rahman 3,*, Ahmed M. M. El-Saghier 3, Doaa Abou El-Ezz 4, Adel A. Marzouk 5, Mohamed R. Shehata 6 and Ehab M. Abdalla 7 1 Chemistry Department, Faculty of Girls for Science, King Khalid University, Abha 61421, Saudi Arabia 2 Chemistry Department, College of Science, University of Jeddah, Jeddah 21959, Saudi Arabia; [email protected] 3 Chemistry Department, Faculty of Science, Sohag University, Sohag 82534, Egypt; [email protected] 4 Pharmacology and Toxicology Department, Faculty of Pharmacy, October University for Modern Sciences and Arts (MSA University), Giza 12556, Egypt; [email protected] 5 Department of Pharmaceutical Chemistry, Faculty of Pharmacy, Al-Azhar University, Assiut Branch, Assiut 71524, Egypt; [email protected] 6 Citation: Al-Farhan, B.S.; Basha, Chemistry Department, Faculty of Science, Cairo University, Giza 12613, Egypt; [email protected] 7 M.T.; Abdel Rahman, L.H.; El-Saghier, Chemistry Department, Faculty of Science, New Valley University, Alkharga 72511, Egypt; [email protected] or [email protected] A.M.M.; Abou El-Ezz, D.; Marzouk, * Correspondence: [email protected] (B.S.A.-F.); A.A.; Shehata, M.R.; Abdalla, E.M. [email protected] or [email protected] (L.H.A.R.); Synthesis, DFT Calculations, Tel.: +20-1098856153 (L.H.A.R.) Antiproliferative, Bactericidal Activity and Molecular Docking of Abstract: Despite the common use of salens and hydroxyquinolines as therapeutic and bioactive Novel Mixed-Ligand Salen/ agents, their metal complexes are still under development.
    [Show full text]