A Possible Model for Nickel Superoxide Dismutase

SYNTHESIS AND CHARACTERIZATION OF NICKEL IMINE/AMINE COMPLEXES; A POSSIBLE MODEL FOR NICKEL SUPEROXIDE DISMUTASE

A Thesis by

Tom Muinde Mwania

Bachelor of Science, Wichita State University, 2008

Submitted to the Department of Chemistry and the faculty of the Graduate School of Wichita State University in partial fulfillment of the requirement for the degree of Masters of Science

May 2012

SYNTHESIS AND CHARACTERIZATION OF NICKEL IMINE / AMINE COMPLEXES; A POSSIBLE MODEL FOR NICKEL SUPEROXIDE DISMUTASE

The following faculty members have examined the final copy of this thesis for form and content, and recommended that it be accepted in partial fulfillment of the requirement for the degree of Master of Science with a major in Chemistry.

______David M. Eichhorn, Committee Chair

______D. Paul Rillema, Committee Member

______William C. Groutas, Committee Member

______George Bousfield, Committee Member

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DEDICATION

For my family and friends, for all of their support

ACKNOWLEDGEMENTS

It would not have been possible to write this thesis without the help and support of Dr.

David M. Eichhorn, principal supervisor, whom am really grateful for his patience with me, not to mention his advice and unsurpassed knowledge in chemistry and crystallography, his guidance and direction has really made an impact in my academic and research work. Also I would like to thank the rest of my committee members: Dr. Rillema, Dr. Groutas, and Dr. Bousfield, for their support and cooperation to make this possible. I would like to acknowledge the faculty and staff of the Wichita State University Chemistry Department for academic, technical and financial support. I would like to thank my lab and class colleagues both past and present: Anh Tran, Eric

Oweggi, Nilmini, Nguyen, Lava, John, Wade and Megan.

Finally, I would like to thank two of the most important people in my life i.e. my mum and my wife Kitra Mwania for their encouragement and patience during my graduate studies, and also my brothers and other family members, who have also been giving me their unequivocal support.

ABSTRACT

Superoxide dismutases are ubiquitous enzymes that efficiently catalyze the disproportionation of superoxide radical anions to protect biological molecules from oxidative damage. Several SODs have been identified having different metals at their active sites. These include Mn SOD, Fe SOD, Cu/Zn SOD and, most recently, Ni SOD. The catalytic center of Ni

SOD resides in the N-terminal active-site loop, where a Ni(II) is coordinated by the amine N of

His-1, the amide N of Cys-2, and two thiolate S atoms of Cys-2 and Cys-6. In the oxidized form,

Ni(III) adds the imidazole N of His-1 as an axial ligand. For the past decade, we have been developing methodology using 2, 2’-dithiodibenzaldehyde (DTDB) for the synthesis of metal complexes with mixed N/S coordination. We are reporting on the application of this methodology to the synthesis of model complexes for the active site of NiSOD, in which we

II have successfully synthesized and characterized three Ni N2S2 complexes of imine/amine N

t donors: Ni(NNS)SPh (1), Ni(NNS)SPhNO2 (2) and Ni(NNS)S Bu (3). These may be used as a model for reduced NiSOD, with future plans of comparing to complexes with amide/amine N donors, thus establishing the role of the amide.

TABLE OF CONTENTS

Chapter Page

1. INTRODUCTION……………………………………………………………………1

1.1 Superoxide Dismutases …………………………………………………………..1

1.1.1 Structure ……………………………………………………………...2 1.1.2 Redox Properties ……………………………………………………..3 1.1.3 Catalytic Mechanism …………………………………………………4

1.2 NiSOD Model Complexes ……………………………………………………….7

1.2.1 Computational Modeling ……………………………………………..7 1.2.2 Synthetic Models ……………………………………………………...9 1.2.3 Peptide Models …………………………………………………...... 16

1.3 Past DTDB work of relevance …………………………………………………...18

2. SYNTHESIS AND CHARACTERIZATION OF OTHER METAL COMPLEXE

2.1 Introduction ……………………………………………………………………….21

2.2 Ni(NNS)(SR) Complexes ………………………………………………………....22

2.2.1 Synthesis ………………………………………………………………22 2.2.2 Structural Characterization ……………………………………………23 2.2.3 Electronic Spectroscopy ………………………………………………28 2.2.4 Electrochemistry ……………………………………………………..29

2.3 Attempt to synthesize other nickel complexes…………………………...... 31

2.3.1 Complexes with pendant N donor………………………………………31

2.4 Complexes with a propyl bridge…..……………………………………………...... 33

2.5 Complexes with other metal………..……………………………………………….34

2.6 Experimental ………………………………………………………………………..35

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TABLES OF CONTENTS (continued)

Chapter Page

2.6.1 General Experimental …………………………………………………35 2.6.1 Synthesis of Ni(NNS)SPh (1) …………………………………………37 2.6.1 Synthesis of Ni(NNS)SPhNO2 (2)……………………………………..37 2.6.1 Synthesis of Ni(NNS)StBu (3)…………………………………………38 2.6.1 Synthesis of Ni(NNS)’Cl ………………...……………………………38 2.6.1 Synthesis of Ni(NNS)’StBu ……………………………………………39 2.6.1 Synthesis of Co(deaeba)Cl3 (4) ………………………………………...39 2.6.1 Synthesis of Ni(NNS)SC2H4NH2 ……………………………………...40 2.6.1 Synthesis of Ni(NNS)SC2H4N(CH3)2 ………………………………….40 2.6.1 Synthesis of Ni(NNS)SEt ………………………………………………40 2.6.1 Synthesis of Ni(NNS)’SPh ……………………………………………..41 2.6.1 Synthesis of Ni(NNS)’SPhNO2 ………………………………………...41

3 CONCLUSION ………………………………………………………………………..42

REFERENCES …………………………………………………………...... 43

APPENDICES …………………………………………………………………………49 A. Crystallography Data Parameters …………………………………………..50

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LIST OF TABLES

Table Page

1.2.2.1 Electronic absorption spectral properties & oxidation potentials of complexes 2 – 6 reported in MeCN at 298 K ……………………………………………………11

1.2.3.1 The electrochemical values for compounds illustrated in Figure 1.2.3.1 ……………17

2.2.2.1 Selected bond length in (Å) & angles (°) for Ni(NNS)(SR) …………………………26

2.2.2.2 Shows bond distance (Å) for NiSOD & NiN2S2 model complexes ………………….27

2.2.3.1 Electronic absorption spectral properties in MeCN at 298 K ………………………...28

2.2.4.1 Oxidation & reduction potentials of compound 1 – 3 in MeCN at 298 K w/o Pyrazole……………………………………………………………………………….29

2.2.4.2 Oxidation & reduction potentials of compounds 1 – 3, in MeCN at 298 K w Pyrazole ………………………………………………………………………………29

2.6.1 Shows atomic bond distances between N1 – S1 & Co – N2 …………………………...34

LIST OF FIGURES

Figure Page

1.1.1.1 Truncated structures of NiSODred & NiSODox ………………………………………..3

1.1.3.1 Proposed catalytic cycle for superoxide degradation in NiSOD. Ni3+ oxidation state is found in the unbound His-imidazole ring complex (structure I and II)……….5

1.1.3.2 NiSOD catalytic mechanism as proposed by Getzoff …………………………………6

1.2.1.1 Energy minimization of oxidized (NiIII(SOD-on)) and reduced ((NiII(SOD-off)) NiSOD computational models were performed by DFT methods …………………….8

1.2.2.1 Active site of Ni-SODred (left), Ni-SODox (middle), and Ni-SOD synthetic model systems, {Ni(nmp)(SR)}- (right). Bottom: R groups {RSH = HSC6H4-P-Cl (2), HStBu (3), o-benzoylaminobenzene thiol (4), N-(2-mercaptoethyl)benzamide (5), and N-acetyl –L-cysteine methyl ester (6) …………………………………………….9

t 1.2.2.2 ORTEP diagrams of Ni(nmp)(SC6H4-P-Cl)(2) and Ni(nmp)(S Bu) (3) as determined by Harrop ………………………………………………………………...10

1.2.2.3 ORTEP diagrams of the anion of (Et4N){Ni(nmp)(S-o-babt)} (4), (Et4N){Ni(nmp)(S-meb)} (5) …………………………………………………………10

1.2.2.4 Redox equilibrium between 1 (X-ray structure with 50% thermal ellipsoid &H atoms omitted) and 3* (optimized structure; Im = Imidazole)………………………………...... 12

1.2.2.5 X-band EPR spectrum of 3 obtained after the addition of 2.5 equiv of Imidazole in electrogenerated 2, recorded in CH2Cl2 (0.1 M Bu4NPF6) at 100 K…………………...... 13

Ph,Me Ph,Me 1.2.2.6 X-ray crystal structure of Tp NiS2CNPh2(left), Tp NiS2CNEt2 (center), Ph,Me and Tp NiS2COEt (right) ………………………………………………………….13

1.2.2.7 Chemdraw of Masuda Ni(II) complex ………………………………………………...15

1.2.2.8 Ni(BEAAM) as determined by Shearer & Zhao ………………………………………15

LIST OF FIGURES (continued)

Figure Page

1.2.3.1 NiIII/II(SODM1-Im-X) X = Me, H, DNP, & TOS ………………………………………16

2.2.2.1 50% thermal ellipsoid ORTEP drawing of {Ni(NNS)SPh} (1), {Ni(NNS)SPhNO2} (2) and {Ni(NNS)StBu} (3) showing thermal ellipsoid for all non-hydrogen atoms (H-atoms omitted for clarity)………………………………………………………..24-25

2.2.4.1 Cyclic voltammogram of 1.8 mM compound 2 {Ni(NNS)SPhNO2} solution in CH3CN in 0.1 M tetrabutyl ammonium perchlorate at vitreous platinum electrode (3 mm diameter) ………………………………………………………….30

2.3.1.1 50% thermal ellipsoid ORTEP drawing of {Ni(NNS)Cl} (5)………………………….32

2.4.1 ESI-MS spectrum of {Ni(NNS)’StBu} ………………………………………………..33

2.5.1 ORTEP showing 50% thermal ellipsoid of {Co(deaba)Cl3} (4) ……………………...35

LIST OF SCHEMES

Scheme Page

1.3.1 DTDB synthesis schematic ……………………………………………………………18

1.3.2 Synthesized compounds in our lab related to my research ……………………………19

2.2.1.1 Schematic formation of {Ni(NNS)SPh} (1), {Ni(NNS)SPhNO2} (2), and {Ni(NNS)StBu} (3) ……………………………………………………………..23

2.3.1.1 Schematic formation of compound (Ni(SNS))2 …………………………………….31

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LIST OF ABBREVIATIONS

Asp Aspartic Acid

CH2Cl2 Dichloromethane

Cys Cysteine deaeba 2- (2-Dimethylamino-ethyl)-benzo[d]isothiazol-2-ium tetraphenylborate

DFT Density Functional Theory

TD-DFT Time Dependent Density Functional Theory dmap N,N-dimethyldiaminopropane dmen N,N-dimethylethylenediamine

DMF Dimethylformamide

DTDB 2-2’-dithiodibenzaldehyde en Ethylenediamine

EPR Electron Paramagnetic Resonance

ESI-MS Electrospray Ionization Mass Spectrometry et Ethyl

ET Electron transfer

Gly Glycine

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LIST OF ABBREVIATIONS (continued)

His Histidine

IR Infrared kDa Kilodaltons

LAH Lithium Aluminum Hydride

Leu Leucine

Me Methyl

MeCN Acetonitrile

MeOH Methanol mV Millivolt

NHE Normal Hydrogen Electrode

NiSOD Nickel Superoxide Dismutase

NMR Nuclear Magnetic Resonance

ORTEP Oakridge Thermal Ellipsoid Program

PCC Pyridinium Chlorochromate

Ph Phenyl

Pro Proline

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LIST OF ABBREVIATIONS (continued)

SOD Superoxide Dismutase tsalen Thiosalen or N,N’-ethylenebis(thiosalicylideneamine)

Tyr Tyrosine

UV Ultraviolet

Vis Visible

CHAPTER 1

INTRODUCTION OF NISOD

1.1 Superoxide Dismutases

Superoxide dismutases (SODs) are metalloenzymes found in living organisms that protect from the damaging effects of the superoxide radical. This is done by catalyzing the

. - disproportionation of O2 (superoxide) into O2 (molecular oxygen) and H2O2 (hydrogen

9 -1 -1 peroxide) [1][2] at physiological pH and at rates near the diffusion limit (kcat-10 M s ).

Superoxide disproportionation is catalyzed through a ping-pong mechanism that involves electron transfer to and from the metal center that cycle between the reduced state and oxidized state, as shown in equations 1 and 2 [1-4].

red .- + ox M + O2 +2H M + H2O2 (1)

ox .- red M + O2 M + O2 (2)

Superoxide toxicity has been implicated in a number of medical conditions, including

Alzheimer’s and Parkinson’s diseases, certain cancers, familial amyotrophic lateral sclerosis, and aging [5-13], thus indicating the critical role these metalloenzymes play in organisms. There are four known superoxide dismutases of which the first three, i.e., Fe-, Mn-, and Cu/Zn-SOD [1, 14,

15] have been known for many years and have been thoroughly investigated. FeSODs are found in prokaryotes and in plants, MnSODs are found in prokaryotes and in the mitochondria of humans, and Cu/ZnSODs are found in the cytosol of eukaryotic cells and in the perioxisomes. A recently discovered class of SOD containing Ni has been isolated from Streptomyces species

[16-19] and several cyanobacteria [20].This newly discovered enzyme, is different from others

SODs in terms of spectroscopic properties, active-site ligand environment, and amino acid sequence.

1.1.1 Structure

Cu/ZnSOD is a 32 kDa homodimeric or monomeric β-barrel protein in which each monomer of the molecule binds one copper and one zinc ion, displaying the Greek Key motif

[21]. Crystallographic and spectroscopic studies have demonstrated that a histidyl residue (His63 in human and yeast) coordinates the copper and zinc ions simultaneously in the cupric form of the enzyme. This histidine residue, termed the “histidine bridge” or “bridging imidazolate,” is a motif so far observed only in Cu/ZnSOD. In the cupric form of SOD the copper binding geometry is described as distorted square planar, with histidine residues 46, 48, 63, and 120 acting as ligands in the human and yeast proteins [16, 22, 23-29].

MnSOD and FeSOD are homologous homodimeric or homotetrameric proteins with a two domain primary alpha-helical fold [30]. The structure has three histidine residues, one aspartic acid, and a solvent molecule in a trigonal bipyramidal geometry coordinating the metal.

NiSOD is a homohexamer of approximately 13 kDa monomers, with each containing one Ni atom [31, 32]. NiSOD exists in two states: oxidized state and reduced state. In the oxidized state, the geometry of the ligand environment is square-pyramidal with the imidazole donor from histidine(His 1) in the axial position and two cis-thiolates from cysteine residues (Cys2 and

Cys6), a deprotonated amide from the Cys2 backbone, and the N-terminal –NH2 group of His1 in the basal positions (Fig. 1.1.1.1) [31,32]. In the reduced state of NiSOD, the side chain of His 1 is rotated away, such that the distance between Ni and His 1 is significantly larger resulting in a square-planar geometry around the Ni2+ [31,32].

Comparing NiSOD with other SOD enzymes, NiSOD is the only SOD family in which the coordination number changes as a function of the metal ion oxidation state [38]. Also, the

NiSOD active site environment is different from other SODs. It has two Cys thiolates coordinated to the nickel, which is surprising since they would be susceptible to oxidation by

.- derivatives of O2 . Moreover, the coordination by deprotonated amides [47, 48] and the ligation by the N-terminal amine [49, 51] have been established in only few cases.

Figure 1.1.1.1 Truncated structures of NiSOD red and NiSOD ox [33]

1.1.2 Redox properties.

A requirement for any SOD is a one-electron redox potential that lies between the

-. .- potentials for oxidation and reduction of O2 The O2/O2 couple has been reported at a potential

.- of -0.16 V (vs. NHE) and the O2 /H2O2 redox couple is 0.870 V [34]. The midpoint potential for

Equations 1 and 2 is approximately 0.36 V in aqueous solution at pH 7. Cu/Zn, Fe and Mn SODs have measured redox potentials that range close to 0.3 V with a deviation of 0.1 V [35]. The redox couple of each metal in the SODs makes up the one electron transfer system. One of the most intriguing aspects about the NiSOD is that aqueous Ni2+ is not capable of SOD activity [36] unlike Cu2+, Mn2+ and Fe2+, since the Ni(III/II) couple lies at over +1 V and the Ni(II/I) couple is lower than -1 V. However, a redox potential of 0.286 V has been measured for NiSOD [37], thus suggesting the idea that the unusual protein or ligand environment is responsible for decreasing the potential of Ni(III/II).

1.1.3 Catalytic Mechanism

Detailed investigations of the catalytic mechanism of the NiSOD enzyme have been conducted by several investigators. Inner sphere and outer sphere mechanisms are the possible electron transfer mechanisms for NiSOD, depending on whether or not the substrate is bound in the first coordination sphere of the nickel ion. Buntkowsky and coworkers have been able to show support for the inner-sphere electron transfer mechanism [38] by synthesizing and characterizing metallopeptide substrate model complexes employing cyanide as a substrate analogue. Another proposed catalytic mechanism by Barondeau [31] found that the superoxide coordinates above the plane of the square planar coordination environment at the active site of the NiSOD enzyme while the His1-imidazole side chain can coordinate from the opposite side of the nickel ion forming a trigonal pyramidal (structure 2 in figure 1.1.3.1) or an octahedral

(structure 4 in figure 1.1.3.1) transition state. Also Getzoff proposed that the properly positioned backbone amide of Asp3 or Cys6 or the hydroxyl of Tyr9 can donate protons for hydrogen peroxide formation. NiSOD Tyr 9 is positioned as a proton donor 5 Å away from the nickel

4 center. Recent studies on Tyr9 mutants by Maroney and co-workers have shown a decrease in activity and H2O2 saturation kinetics not observed for wild-type enzyme, highlighting the importance of Tyr9 in catalysis and proposed role to aid in the release of hydrogen peroxide [39].

Figure 1.1.3.2 shows a catalytic mechanism proposed by Getzoff showing the importance of

Tyr9.

Figure 1.1.3.1 Proposed catalytic cycle for superoxide degradation in NiSOD. Ni3+ oxidation state is found in the bound His imidazole ring complex (structure III and IV), while Ni2+ oxidation state is in the unbound His-imidazole ring complex (structure I and II) [40].

Figure 1.1.3.2 NiSOD catalytic mechanism as proposed by Getzoff [31].

1.2 NiSOD Model Complexes

The main goal of this research is to synthesize model compounds that may give us insight and understanding into how the NiSOD active site works, however there are numerous approaches to reach this goal. There are three different kinds of models that have been designed and discussed in scientific journals relating to NiSOD. The first is the computational approach, which is becoming more popular since it is more economical and provides reliable values that may be used as supporting information. The second is the synthetic method, which will be discussed in depth since my research falls under this category. The third involves peptide-based models, which have shown great promise since they are the only models that have so far shown superoxide dismutase activity. However, I will still emphasize that in my opinion all three approaches have great potential to give insight about how the enzyme works and its chemistry.

1.2.1 Computational modeling.

Brunold and coworkers performed computational studies using DFT and TD-DFT calculations to optimize the geometries and predict the transition energies and electronic absorption intensities, respectively, for five- and six-coordinate active-site models [33]. Also other groups have used computational studies to estimate the inner-sphere reorganization energies and the bond distances, e.g. Shearer and coworker’s paper [41] as shown in figure

1.2.1.1, to obtain values for the self-exchange reactions where the imidazole remains on or off during electron transfer (ET), force constants and atomic coordinates for imidazole ligated

(NiII(SOD-on)) and imidazole unligated NiIII(SOD-off) were obtained. This was done by using

(NiII(SOD-off)) and NiIII(SOD-on) as starting structures, followed by oxidation or reduction of

7 the Ni-center and subsequent geometry optimizations. They minimized structures for NiIII(SOD- off), low-spin (NiII(SOD-onl.s.)), and high spin (NiII(SOD-onh.s.)) (figure 1. 2.1.1).

Figure 1.2.1.1 Energy minimizations of the oxidized (NiIII(SOD-on)) and reduced ((NiII(SOD- off))-) NiSOD computational models were performed by DFT methods [41].

Using the procedure outlined above for the NiIII(SOD-off)/(NiII(SOD-off))- self-exchange electron transfer (ET) reaction was calculated to be 16.2 kcal mole-1. The bond distances are as shown in figure 1.2.1.1 and were similar to other computational models.

1.2.2 Synthetic Models

Several groups have reported compounds that have similar structures to the active site of

NiSOD. Harrop and coworkers have synthesized an array of donor centers that replicate the

- asymmetric nature of the N2S2 donor set, and characterized the synthetic {Ni(nmp)(SR)} compounds shown below in figure 1.2.2.1 [42]. These complexes are good structural analogues with the pyridyl-N, carboxamide-N, and thiolato-S of the nmp2- ligand modeling the contributions of His-1 and Cys-2 in NiSOD. The addition of the thiolate allows for variable and unconstrained modeling of Cys-6 in NiSOD utilizing electronically different thiolate ligands.

Figure 1.2.2.1 Active Site of Ni-SODred (left), Ni-SODox (middle), and Ni-SOD Synthetic Model

− t Systems, {Ni(nmp)(SR)} (right). (Bottom): R Groups RSH = HSC6H4-p-Cl (2), HS Bu (3), o-

9 benzoylaminobenzene thiol (4), N -(2-mercaptoethyl)benzamide (5), and N-acetyl-L-cysteine methyl ester (6) [42].

X-ray crystallography was used to characterize these compounds and the bond distances were about in the range with reduced NiSOD [31]. The NiN2S2 coordination geometry remains distorted square planar around the NiII in all the complexes with little deviation from the least – squares plane defined by the donor atoms.

t Figure 1.2.2.2 ORTEP diagrams of Ni(nmp)(SC6H4-p-Cl) (2) and Ni(nmp)(S Bu) (3) as determined by Harrop [42].

Figure 1.2.2.3 ORTEP diagram of the anion of (Et4N)[Ni(nmp)(S-o-babt)] (4)

(Et4N)[Ni(nmp)(S-meb)] (5) [42].

Cyclic voltammetry measurements of 2-6 revealed irreversible oxidation events in MeCN solvent (vs Ag/AgCl, RT). The authors suggested that the irreversibility of the oxidation event is either ligand based oxidation or an unstable NiIII species that is short lived due to autoredox. The electronic absorption spectral properties and oxidation potentials of complexes 2-6 are reported as shown in Table 1.2.2.1.

Table 1.2.2.1 Electronic Absorption Spectral Properties and Oxidation Potentials of

Complexes 2-6 Reported in MeCN at 298 K [42]

2 3 4 5 6

λmax (nm) 450 464 450 449 442

ε (M-1 cm-1) 5450 4540 3500 3900 3710

Eox (mV) 236 75 276 214 286

Moreover, 2, 4, 5 and 6 have midpoint potential values close to the protein value of 490 mV (vs

Ag/AgCl, pH 7.5 phosphate buffer) [39]. The compounds did not show superoxide activity even upon addition of 10 equivalents of imidazole. This, the group suggested, might be due to the instability of NiIII.

II Duboc and coworkers have made a synthetic compound Ni N2S2 that also mimics the redox structural changes of NiSOD. They showed that their structure undergoes metal-based oxidation, and even more interesting, an electrochemical investigation that showed the

III + reversible, oxidation-state-dependent generation of a square pyramidal [Ni N3S2] complex in the presence of imidazole. The group used EPR coupled with DFT calculations to demonstrate that the nickel character in the redox active orbital increases drastically upon imidazole binding ,

11 which would favor Ni oxidation over S oxidation [43]. Figure 1.2.2.4 shows the crystal structure

II III of Ni N2S2 1 and DFT optimized structure of Ni N2S2 3.

Figure 1.2.2.4 Redox equilibrium between 1 (X-ray structure with 50% thermal ellipsoids and H atoms omitted) and 3* (optimized structure; Im=imidazole). Selected bond distances in 1 (Å):

Ni(1)-S(1)=2.1732(6), Ni(1)-S(2)=2.1759(6), Ni(1)-N(1)=1.9345(16), Ni(1)-N(2)= 1.9352(16)

[43].

The cyclic voltammogram displays two one-electron metal-based processes: a quasi-

II I + III II reversible Ni /Ni reduction wave at E1/2 = -1.68 V vs Ag/Ag and an irreversible Ni / Ni oxidation peak at Epa = +0.34 V. By bulk oxidation at E = +0.38 V, they were able to obtain a stable EPR-silent, orange solution that corresponds to quantitative formation of a NiIII dimer. The addition of up to 2.5 equivalents of imidazole in an electrogenerated solution as explained above, leads to progressive appearance of a new irreversible reduction peak at Epc = -0.2 V. The resulting red solution displayed a rhombic EPR S=1/2 signal consistent with Ni(III) as shown in figure 1.2.2.5. The three-line superhyperfine pattern in the gz component is assigned to a single

15 nitrogen donor atom ( IN=1) arising from the imidazole ligand axially bound to the Ni ion [43].

Figure 1.2.2.5 X-band EPR spectrum of 3 obtained after the addition of 2.5 equiv of imidazole in electrogenerated 2, recorded in CH2Cl2 (0.1M Bu4NPF6) at 100 K. Parameters used for the simulation: gx=2.315, gy=2.177, gz= 2.029, and Az=54MHz [43].

The species 3 in figure 1.2.2.4 can also be generated via bulk electrolysis at +0.38 V of 1 in the presence of 2.5 equiv of imidazole. By exhaustive reduction of 3 at -0.4 V, it regenerated 1 with a yield of 85%, showing the reversibility of the coordination process of the imidazole [43].

Jensen and coworkers have also reported three crystal structures, in which they used scorpionate ligands, i.e. they utilized the hydrotris(3-phenyl-5-methylpyrazolyl) borate ligand (

TpPh,Me) to mimic the monoanionic facial array of nitrogen donors and 1,1-S,S’-chelating

- - dithiocarbamates (R2NCS2 , R = Et, Ph) and organoxanthate (EtOCS2 ) as coligands to mimic the dithiolate coordination. The scorpionate donor can adopt variable κ2 or κ3 chelate modes. The crystal structures of their three complexes confirm square-planar N2S2 ligand fields for the

2 3 dithiocarbamates and a square-pyramidal N3S2 field for the xanthate with κ and κ scorpionate ligands, respectively [52], as shown in figure 1.2.2.6.

Ph,Me Ph,Me Figure 1.2.2.6 X-ray crystal structures of Tp NiS2CNPh2 (left), Tp NiS2CNEt2 (center),

Ph,Me Ph,Me and Tp NiS2COEt (right). Coordinate bond lengths (Å) for Tp NiS2COEt: Ni-S1,

2.201(1);Ni-S2, 2.183(1); Ni-N1, 1.910(2); Ni-N3, 1.911(1); Ni · · · N6, 3.541. For

Ph,Me Tp NiS2CNEt2: Ni-S1, 2.199(1); Ni-S2, 2.193(1); Ni-N1, 1.929(1); Ni-N3,1.934(1); Ni · · ·

Ph, Me N6, 2.805. For Tp NiS2COEt: Ni-S1, 2.399(1); Ni-S2, 2.379(1); Ni-N3, 2.042(2); Ni-N5,

2.078(1); Ni-N1, 2.052(2) [52].

All three complexes exhibited quasi-reversible one-electron couples by cyclic voltammetry in

0 CH2Cl2 solutions, with observed E ’ values reflecting the relative donor strengths of S,S’-

Ph,Me Ph,Me Ph,Me chelates: Tp NiS2CNPh2 = - 80 mV, Tp NiS2CNEt2 = 50 mV, and Tp NiS2COEt =

260 mV. These values fall in a range suitable for NiSOD activity, suggesting these might function as catalysts under appropriate solvent conditions [52].

Masuda and coworkers have also reported a Ni(II) complex with N2S2 square-planar geometry, and identified interesting structural behavior exhibited during the reaction of the complex with superoxide. The Ni(II) center of the complex has C2 symmetry with square-planar geometry. The ligands are provided by two amine nitrogens and two thioether sulfurs. The complex has absorption band characteristics of Ni(II) complexes with a square-planar structure at

474 nm (210 ɛ/M-1cm-1 in MeOH). The Ni(II) complex produced reversible and quasi-reversible

14 redox potentials corresponding to Ni(I)/(II) and Ni(II)/(III) couples at -0.68 and 1.71 V (vs.

NHE), respectively. The complex is oxidized by KO2 to Ni(III) in MeOH. The same product was shown to be formed in a reaction between the reduced product of Ni(II) complex and O2 [53].

Figure 1.2.2.7 Masuda Ni(II) complex.

Shearer and Zhao have reported a synthetic model for nickel superoxide dismutase that

II contains Ni in a mixed amine/ amide coordination environment [Me4N](Ni (BEAAM)), as shown in figure 1.2.2.8. It contains Ni -S bonds at 2.177(2) and 2.137(2) Å and Ni-N bonds at

1.989(7) and 1.858(6) Å, which compare well with the metalloenzyme. They observed a quasireversible NiII/III redox couple at 0.21(1) V vs Ag/AgCl. They suggested that NiSOD

II/III .- utilizes the mixed amine/amide ligand to modulate the Ni redox couple to best match the O2 reduction/oxidation couples while maintaining O2 stability [54].

Figure 1.2.2.8 Ni(BEAAM) as determined by Shearer & Zhao [54].

1.2.3 Peptide Models.

Several researchers have prepared metallopeptides that have been used for studying

NiSOD. Shearer and coworkers have prepared a series of metallopeptides that closely mimic the spectroscopic and structural properties of the enzyme ({NiIII/II(SODM1-Im-X)} X = Me, H, DNP, and Tos; SODM1-Im-X = H'CDLPCGVYDPA where H' is an N-substituted His), from first the

12 residues of the NiSOD protein. The structures are shown in figure 1.2.3.1.

Figure 1.2.3.1 [44] ({NiIII/II(SODM1-Im-X)} X = Me, H, DNP, and Tos}).

The group used a strong oxidant to oxidize these metallopeptides to the NiIII oxidation

III M1 7 -1 -1 .- state. SOD activity of {Ni (SOD -Im-H)} was 7(3) x 10 M s . The O2 disproportionation kinetics of the other three metallopeptides were also investigated using stopped flow kinetics.

They found that all three of the N-substituted imidazole substituted metallopeptides are capable

.- of facilitating the catalytic disproportionation of O2 . The metallopeptide with the most electron

III III M1 .- rich Ni -center, {Ni (SOD -Im-Me)}, had the slowest O2 degradation kinetics of the four metallopeptides investigated (k = 6(1) x 106 M-1 s-1). In contrast, both {NiIII(SODM1-Im-DNP)}

III M1 .- III M1 and {Ni -(SOD -Im-Tos)} display O2 degradation kinetics that are faster than {Ni (SOD -

Im-H)} with k=4(2) x 108 M-1 s-1 and 6(2) x 108M-1 s-1, respectively [44].The electrochemical values are as shown in Table 1.2.3.1.

Table 1.2.3.1 Electrochemical values for compounds illustrated in Figure 1.2.3.1.

E(V vs Ag/Ag+) {NiII(SODM1-Im-Me)} 0.282 {NiII(SODM1-Im-DNP)} 0.47 {NiII-(SODM1-Im-Tos)} 0.598 {NiIII(SODM1-Im-Me)} nd not determined = nd

All four metallopeptides yield quasireversible NiIII/NiII redox couples in solution. The more electron donating imidazole donor {NiD II(SO M1-Im-Me)}, stabilizes the NiIII oxidation state to greater extent with a redox couple of E = 282(4) mV versus Ag/Ag+, while the less electron donating ligands provide for more positive redox potentials with E = 470(10) and 598(5) mV versus Ag/Ag+ for {NiII(SODM1-Im-DNP)} and NiII-(SODM1-Im-Tos)}, respectively [44].

Weston and coworkers examined several SOD-active metallopeptides based on the first six and nine residues, respectively, from the N terminus of NiSOD from S. coelicolor. The 3D

NMR solution structure of the peptide exhibits, in contrast with the cis Leu4-Pro5 bond in the

NiSOD enzyme, a trans Leu4-Pro5 bond. They concluded that the finding could have strong similarity of the proposed catalytic mechanisms of the synthetic metallopeptides and native

NiSOD enzyme [56].

Laurence and coworkers have reported that a coordination sphere of NiSOD can be mimicked by a tripeptide using, asparagine-cysteine-cysteine (NCC), which exhibited both quasi-reversible NiII/NiIII with a midpoint potential of 0.72(2) V (vs Ag/AgCl) and SOD activity

-5 with IC50 value of 4.1 x 10 M. NCC is unique because it is not derived from the sequence of the parent enzyme and because of its small size, this tripeptide is likely to have better stability and a lower cost of production than larger peptide alternatives [55].

1.3 Past DTDB (2, 2’-dithiodibenzaldehyde) work of revelance.

Dr. Eichhorn’s group has been able to use 2, 2-dithiodibenzaldehyde (DTDB) as a precursor in the synthesis of N2S2 and other N/S ligands. The synthesis of DTDB is already an established methodology which can be found in the literature [45]. The schematic for the synthesis of DTDB is shown below (Scheme 1.3.1). DTDB provides a stable way for synthesizing thiolate donating ligands without the need for protecting the thiolate group, thus allowing the thiolate to coordinate with the metal. The reaction of DTDB with metal-coordinated primary amines has yielded metal complexes with N/S ligands, which are a result of Schiff- base condensation and reductive cleavage of the disulfide bond [46]. It is not clear what generates the reducing equivalent for the disulfide bond.

Scheme 1.3.1 DTDB synthesis schematic.

Among the compounds synthesized using DTDB are those involving chelating NN precursors.

Some of the compounds of relevance to my research are Ni(tsalen) (1) [46b], Ni(NNS)Cl (2),

+ Ni(NNS)NO3 (3), Ni(NNS)NO2 (4), and Ni(NNS)(Im S)BPh4 (5) [57, 58]. Scheme 1.3.2 shows some of the compounds that have been synthesized in Dr. Eichhorn’s lab related to my research.

Scheme 1.3.2 Compounds synthesized in our lab related to my research.

The advancement of the methodology over the years has led to various ways that have provided solutions to create a ligand environment that has N2S2 coordination. Prior research in the group used ethylenediamine (en) to synthesize the tetradentate ligand tsalen (SNNS) that coordinated with nickel forming 1 (Ni(tsalen)). They also envisioned that in order to prevent formation of the tetradentate tsalen ligand due to the two primary amines in en reacting with

DTDB, it was necessary to replace en with N, N-dimethylethylenediamine (dmen) which has only one primary amine available for Schiff-base formation [57], leading to formation of a tridentate ligand (N2S). This has resulted in the synthesis of compounds 2, 3, 4 and 5. Compound

5 features imine/amine nitrogen coordination and the crystal structure of 5 features a square-

2+ planar N2S2 coordination, with a Ni center and an imidazole N 5.994 Å from the Ni atom, away from coordination distance; thus it is similar to reduced NiSOD. The isolation of 5 suggested the synthesis of series of related complexes with N(imine)/N(amine)/S(thiolate)2 coordination spheres in which one of the thiolates could be systematically changed to provide different electronic environments. {Ni(NNS)Cl} was chosen as a convenient starting material, as the Cl ligand could be substituted with various thiolates. A related compound, {Ni(NNS)’Cl}2 (with a propyl bridge instead of an ethyl bridge) has also been reported [58] and represents an alternative system for study. This work will be discussed in Chapter 2.

CHAPTER 2

SYNTHESIS AND CHARACTERIZATION OF METAL COMPLEXE

2.1 Introduction

The goal of this research is to model the NiSOD active site, which consists of a nickel center in a square-planar coordination sphere that includes the amine nitrogen of the terminal histidine, amide nitrogen of the peptide backbone, and two cysteine thiolates [31]. By synthesizing models for the active site, information about the surrounding peptide ligand environment could be understood, which could answer some questions, e.g., why the metalloenzyme chooses amine/amide N coordination with two thiolate coordination and how it influences the reactivity? Understanding the fundamental chemistry of the metalloenzyme could lead to answers about the mechanistic details of superoxide disproportionation. By utilizing the

+ DTDB methodology, our group has previously reported {Ni(NNS)(Im S)}BPh4 [57]that has

NiN2S2 coordination with an amine and imine donor, which is similar to the active site of reduced NiSOD. This suggested the possibility of further utilizing DTDB methodology, i.e., the synthesis of {Ni(NNS)Cl}, to synthesize a series of {Ni(NNS)(SR)} complexes. These complexes will eventually be compared to new analogs that have NiN2S2 amine/amide N coordination, thus investigating the effects of the amide in comparison to the imine. We report several asymmetric NiN2S2 and other related Ni(II) or metal complexes that have been characterized, thus giving us insight into the electronics and spatial arrangements of these complexes.

The first part of the project was to use the methodology to synthesize NiN2S2 complexes using a chelating ligand that contains two nitrogen atoms in which one is a primary amine, and in our case we used N, N-dimethylethylenediamine. Then reacting it with DTDB to give us a

(NNS) tridentate ligand that will coordinate to the Ni, and eventually reacting the complex to several thiolates to give us NiN2S2 complexes. In the next part of the project, was to synthesize

NiN2S2 using a different chelating ligand i.e. dmap and repeating the methodology as above. The goal was to compare the effect of the chelate on different series of different thiolates.

2.2 {Ni(NNS)(SR)} Complexes.

2.2.1 Synthesis

{Ni(NNS)Cl} was synthesized as previously reported [57]. The {Ni(NNS)(SR)} complexes were synthesized by addition of several thiolates: sodium thiophenolate, sodium 4-nitrothiophenolate and sodium tert-butyl thiolate in MeOH solutions, to {Ni(NNS)Cl}, leading to formation of

t {Ni(NNS)SPh} (1), {Ni(NNS)SPhNO2} (2) and {Ni(NNS)S Bu} (3) (Scheme 2.2.1.1). The compounds were purified by crystallization.

Scheme 2.2.1.1. Synthetic scheme for {Ni(NNS)SPh} (1), {Ni(NNS)SPhNO2} (2), and

{Ni(NNS)StBu} (3).

The FTIR spectral data for 1, 2, and 3, has CN stretching of frequencies 1605, 1592, 1602 cm-1 respectively, while {Ni(NNS)Cl} has CN stretch at 1617 cm-1. There is no clear correlation between the electronic properties of the thiolate and the CN stretching force constant as observed in {Ni(NNS)Cl} compared to 1, 2, and 3.

2.2.2 Structural Characterization.

X-ray quality crystals were grown by vapor diffusion of hexanes (1, 2) or ether (3) into

CH2Cl2 solution. X-ray data collection and structure solution parameters are given in Table A1.

ORTEP drawings of 1, 2, and 3 are shown in Figures 2.2.1 and selected bond distances and angles are given in Table 2.2.2.1 {Ni(NNS)SPh} (1) crystallizes on a general position in the monoclinic space group P2(1)/n, while {Ni(NNS)SPhNO2} (2) crystallizes on a general position in the monoclinic space group Cc. {Ni(NNS)StBu} (3) crystallizes on a general position in the

23 orthorhombic space group Iba2. The methyl and methylene carbons in 3 show disorder which has been modeled with 2 positions for each atom.

Three crystal structures of compounds having square planar NiN2S2 have been obtained as an active site model of NiSOD as shown in Figure 2.2.2.1. The structures of all three are very similar and they reveal four-coordinate square planar NiII centers arising from the tridentate NNS ligand and the different thiolate ligands. The Ni-N/S distances are as shown in Table 2.2.2.1 and are variable in line with the electronic nature of the donor atom, as the Ni-N1 (imine) is shorter than Ni-N2 (amine) in all three structures. The Ni -S1 distance (trans to the imine) is longer than the Ni-S2 distance (trans to the amine) in all three structures since the imine N has stronger σ donor influence than N amine, therefore resulting in a larger trans influence.

Figure 2.2.2.1 ORTEP drawings of {Ni(NNS)SPh} (1) and {Ni(NNS)SPhNO2} (2) and

{Ni(NN)StBu} (3) showing 50% thermal ellipsoids for all non-hydrogen atoms (H atoms omitted for clarity).One of the disorder components of 3 has been depicted.

Table 2.2.2.1 Selected bond lengths in (Å) and angles (°) for {Ni(NNS)(SR)}.

{Ni(NNS)SPh} {Ni(NNS)SPhNO } {Ni(NNS)StBu} Bond type 2 (1) (2) (3)

Ni - N1 (imine) 1.883(3) 1.8863(16) 1.904(4)

Ni - N2 (amine) 2.013(3) 1.9893(16) 2.018(4)

Ni - S1 2.2194(9) 2.2202(6) 2.2138(16)

Ni-S2 2.1412(9) 2.1320(5) 2.1202(14) N (amine)-Ni-N (imine) 86.22(11) 86.45(7) 87.4(2) N (amine)-Ni-S1 92.14(9) 91.96(5) 91.36(16) N (amine)-Ni-S2 177.20(9) 176.37(5) 174.35(16) N (imine)-Ni-S1 178.13(9) 172.13(5) 177.42(13) N (imine)-Ni-S2 96.30(9) 96.84(5) 96.30(13) S1-Ni-S2 85.39(4) 84.99(2) 85.08(6)

The interatomic distances compare well with other reported bis-imine and bis-amine NiN2S2 [57] and also other NiN2S2 compounds [42, 43, 52, 53, 54]; there is also similarity when comparing

Ni-N/S distances in compounds 1, 2, and 3 to reduced NiSOD [42]; as shown in Tables 2.2.2.2

Tables 2.2.2.2 Bond distances (Å) for NiSOD and NiN2S2 model complexes.

NiSOD reduced [31] Ni-Ncys2 1.91(3) Ni-NHys1 1.87(4) Ni-Scys2 2.19(2) Ni-Scyc6 2.16(2)

(as per Complexes 2 3 4 5 fig. 1.5) Ni-Namide 1.8638(14) 1.882(2) 1.877(3) 1.863(7) Ni(nmp)SR [42] Ni-Npy 1.9470(14) 1.9635(19) 1.947(3) 1.944(7) Ni-S(1) 2.1492(5) 2.1629(7) 2.1518(12) 2.156(3) Ni-S(2) 2.2139(4) 2.1938(7) 2.1939(14) 2.172(3)

Ni-Namine(1) 1.9345(16) Ni-Namine(1) 1.931(4) Ni(II) Complex NiL [43] Ni-Namine(2) 1.9352(16) [53] Ni-Namine(2) 1.931(4) Ni-S1 2.1732(6) Ni-S(1) 2.197(1) Ni-S2 2.1759(6) Ni-S(2) 2.197(1)

Ni-Namide(1) 1.858(6) Ni-Nimine(1) 1.879(3) Ni(NNS)(Im+S) Ni(BEAAM)[54] Ni-Namine(2) 1.989(7) [57] Ni-Namine(2) 2.002(3) Ni-S(1) 2.137(2) Ni-S(1) 2.1392(10) Ni-S(2) 2.177(2) Ni-S(2) 2.2265(9)

In all three structures, the thiolate substituent is out of the plane of the rest of the complex. The position of the thiolate substituent with respect to the coordination plane i.e. Cx –

S1 – Ni (Cx carbon that is bonded to S1) is 108.35°, 110.53°, and 112.60° for 1, 2, and 3, respectively. Since 3 show the highest angle deviation, this could be explained by the bulkiness of the t-butyl substituent. The deviation of the coordination sphere from ideal square-planar can

27 be assessed by the angle between the planes defined by N1 –Ni – N2 and S1 – Ni - S2, which would be 0° for an ideal square-planar geometry. The bond angle of plane between N1 – Ni - N2 /

o o o S1 – Ni - S2 is 1.61 , 8.03 and 5.07 for 1, 2, and 3 respectively. All three compounds showed slight distortion from being a true square plane with 2 having the greatest distortion followed by

3 and 1. However, all three compounds serve as reasonable analogues of the asymmetric NiN2S2 active site geometry of reduced NiSOD.

2.2.3 Electronic Spectroscopy.

Compounds 1-3 are highly soluble in polar aprotic solvents like DMSO, MeCN, CH2Cl2,

THF and DMF, and also are soluble in protic solvents like MeOH. In solvents like MeCN, 1-3 formed colored solutions of brick red which may be presumed to arise from Ni-ligand charge

II transfer transitions characteristic of a square planar Ni N2S2 complexes featuring Imine/amine N donors [57] (Table 2.2.3.1).

Table 2.2.3.1 Electronic absorption spectral properties in MeCN at 298 K

Compound 1 2 3 λmax (nm) 424 434 456 ɛ(M-1 cm-1) 1066 1360 871

All reported λmax values ranged between 420-460 nm, which is also in the range of observed λmax for reduced NiSOD of 450 nm [59]. This compares well with other NiN 2S2 Imine/amine

+ complexes reported previously by our group with λmax 435 nm (Ni(NNS)(Im S)) [57].

2.2.4 Electrochemistry.

Cyclic voltammetry measurements of 1-3 showed similar features. They all showed 3 quasi-reversible redox couples in MeCN solvents (vs Ag/AgCl, RT) table 2.2.4.1.

Table 2.2.4.1 Oxidation and reduction potentials of compound 1-3 in MeCN at 298K w/o pyrazole.

Compound Redox Couples (E°a/E°c) mV 1 492/480 900/800 1286/1136 2 686/626 980/848 1336/1148 3 400/362 860/786 1262/1122

The couples between 400 to 1000 mV were assigned to ligand-based events while the couples greater than the 1000 mV were assigned to the NiIII/II couple. The irreversibility of the oxidation events may be explained by either primary ligand-based oxidation or the poor stability of the

NiIII species that is short-lived [42]. Clearly, the NiIII/II couples are not in the range to catalyze

.- th O2 disproportionation, but it is not surprising since we do not have amides or a potential 5 ligand. Therefore, we thought we might add pyrazole to mimic the 5th ligand, which should eventually lead to observing reversible peak and a reduced potential for the NiIII/II complex.

Table 2.2.4.2 shows the potential values of the compounds after addition of the pyrazole.

Table 2.2.4.2 Oxidation and reduction potentials of compounds 1-3, in MeCN at 298K w pyrazole.

Redox Couples (E° /E° ) Compounds a c Pyrazole mV 1 512/400 1058/854 1300/980 2 656/572 1172/980 1398/1336 3 712/704 944/870 1324/1320

We did not observe any reversible peaks as expected. Our results after addition of pyrazole were expected to have less positive values than without pyrazole; instead we observed a shift of the couple to more positive in all compounds except in compound 2 first couple. Based on the data obtained there was not much significant on the potentials that we could conclusively say that we are stabilizing the NiIII.

Figure 2.2.4.1 Cyclic voltammograms of 1.8 mM 2 {Ni(NNS)SPhNO2} solution in CH3CN in

0.1 M tetrabutyl ammonium perchlorate at a platinum electrode (3 mm diameter), in the presence

(red line) and absence of pyrazole (green).

Compound 3 had the lowest potential followed by 1 and 2 based on the electrochemical data obtained (Table 2.2.4.1). These results appear to correlate with the donor effect of S(1),

30 since the oxidation potential of compounds might be expected to be affected by the donor

t strength of S(1) ( Bu > Ph > NO2Ph). The stronger electron donor donates more electron density to the metal, making it easier to oxidize. The electrochemical values compared well to other

NiN2S2 of bis(amine) [53] and also imine/amine [57], but there was a significant difference with amine/amide [54].

2.3 Attempts to synthesize other nickel complexes.

2.3.1 Complexes with pendant N donor

In order to closely model the coordination geometry of NiSOD, we attempted to synthesize complexes in which the thiolate ligand has a pendant N donor, which would model the His imidazole available to bind the oxidized Ni atom in NiSOD. The 1st attempt involved: 2- aminoethanethiol HCl, which was reacted with NaOH in MeOH to form the sodium thiolate salt.

Reaction of the thiolate salt with {Ni(NNS)Cl} in methanol under nitrogen resulting in the only species isolated being identified as (Ni(SNS))2, which has been previously reported by us [46] and others [60]. For the reaction of {Ni(NNS)Cl} with sodium 2-aminoethanethiolate, brown block crystals were easily formed of (Ni(SNS))2 as shown in Figure 2.3.1.1.

Scheme 2.3.1.1 Schematic formation of compound (Ni(SNS))2

The formation of (Ni(SNS))2 must require that unreacted DTDB was present. The DTDB and Ni may have come from unreacted DTDB/Ni when making {Ni(NNS)Cl}. To avoid this product, one option was to attempt using sodium 2-(dimethylamino)ethanethiolate instead of sodium 2-aminoethanethiolate, since the tertiary amine will prevent Schiff-base condensation with the aldehyde functionality of the DTDB thus preventing the reaction forming (Ni(SNS))2.

As for the reaction of {Ni(NNS)Cl} with sodium 2-(dimethylamino)ethanethiolate in MeOH ; we have so far been unable to isolate the desired product. However, we did isolate a new crystalline polymorph of {Ni(NNS)Cl} (5), that crystallizes on a general position in the monoclinic space group P2(1)/n. A disorder solvent molecule was included.

Figure 2.3.1.1 50% thermal ellipsoid ORTEP drawing of Ni(NNS)Cl (5), hydrogen atoms and solvent eliminated for clarity.

2.4 Complexes with a propyl bridge

The next part of the project was to use a different chelating ligand, i.e. N, N- dimethyldiaminopropane (dmap) in synthesizing nickel compounds with {Ni(NNS)’(SR)} arrangements. The goal was to compare the electronics, redox and spatial arrangements of compounds of { Ni(NNS)(SR)} to compounds with {Ni(NNS)’(SR)} arrangements while comparing to NiSOD. Utilizing the DTDB methodology, {Ni(NNS)’Cl} was synthesized by heating, at reflux, DTDB with NiCl2 and dmap in MeOH, mass spectrometry (ms) and FTIR confirmed the product. {Ni(NNS)’Cl} was reacted with several thiolates (sodium thiophenolate, sodium 4-nitrothiophenolate and sodium tert-butyl thiolate). A good ms was obtained for

Ni(NNS)’StBu with peaks at 279.7, 301.7 and 391.7 m/z , which can be assigned to

{Ni(NNS)’}+, Na + {Ni(NNS)’}+ and Na + {Ni(NNS)’Stbut}+ respectively as shown in figure

2.4.1. We have not yet been able to obtain crystals of this compound or any other compounds of the form {Ni(NNS)’(SR)}.

Figure 2.4.1 ESI-MS spectrum of Ni(NNS)’StBu.

2.5 Other metal complexes

The DTDB methodology has been used successfully to synthesize complexes of Cu, Co and Ni. In this part of the project, we attempted to make complexes of other metals with NNS, as an extension of the DTDB methodology. CoCl2, CuCl2 and MnCl2 and dmen were added to

DTDB in MeOH and heated at reflux for 30 minutes. We have been unable to isolate complexes of the M(NNS)Cl . With Co, we were able to structurally characterize a related complex,

{Co(deaeba)Cl3} (4), having a thiolate S and imine N bond, (deaeba = 2-(2- dimethylaminoethyl)benzo(d)isothiazol-2-ium). The deaeba ligand could result from ring closure of the NNS ligand. Similar chemistry has been previously reported by our group [57,60], although none resulting in coordination of the ligand. The thiolate probably self reacted with the imine nitrogen forming a five member heterocycle. {Co(deaeba)Cl3} (4) crystallizes on a general position in the orthorhombic space group P2(1)2(1)2(1). An ORTEP showing the 50% thermal ellipsoids of (4) is shown in figure 2.5.1 and X-ray data collection and structure solution parameters are given in table A1. It was observed that 4 has longer N1-S1 bond distance compared to reported deaeba [57] or BBITE 2+ [60](Table 2.5.1). The angles between N1-C8-C9,

C7-N1-S1 and C9-N2-Co1 are 108.82°, 118.95°, and 105.25°, respectively.

Table 2.5.1 Comparison of bond distances between N1-S1 and bond distance of Co1-N2

Bond type Bond distance in Å N1-S1 1.718(3) N1-S1 deaeba [57] 1.697(3) N1-S1 & N2-S2 BBITE [60] 1.68(1) & 1.705(9) Co1-N2 2.080(3)

Figure 2.5.1 ORTEP showing 50% thermal ellipsoid of the {Co(deaeba)Cl3} (4), hydrogen atoms were omitted for clarity.

As for Cu and Mn, no new crystals were obtained from the reactions.

2.6 Experimental

2.6.1 General Experimental

Unless otherwise noted, all solvents and reagents were used as received from Aldrich, Acros, and

Fisher Scientific without further purification. 2,2’-dithiodibenzaldehyde [50] and (Ni(NNS)Cl)

[62] were synthesized by literature methods. Dry solvents were distilled from sodium/benzophenone (tetrahydrofuran and toluene), calcium hydride (methylene chloride and

acetonitrile) or Mg(OMe)2 (methanol) as specified. Air-sensitive compounds were manipulated in a Vacuum Atmospheres, Inc. Nexus One dry box, equipped with a variable temperature freezer, or on a double manifold Schlenk line using standard Schlenk techniques. IR spectra were

35 recorded on a Nicolet Avatar 360 FTIR. Electrospray mass spectra were obtained on a Finnigan

LCQ DECA spectrometer. UV-Vis data was collected on a Hitachi U-2010 spectrophotometer.

Electrochemical data was collected on an EG &G Princeton Applied Research potentiostat model

263A with a Pt working electrode, Pt counter electrode, and Ag/AgCl reference electrode.

Elemental analyses were obtained from M-H-W Laboratories, Phoenix, AZ. For the X-ray structures, crystals were selected under a polarizing microscope, affixed to a nylon cryoloop

(Hampton Research) using oil (Paratone-n, Exxon), and mounted in the cold stream of a Bruker

Kappa – ApexII area detector diffractometer. The temperature at the crystal was maintained at

150 K using a Cryostream 700 EX low – temperature apparatus (Oxford Cryosystems). The unit cells were determined from the setting angles of the reflections collected in 36 frames of data.

Data were measured using graphite mono-chromated molybdenum Kα radiation (λ = 0.71073 Å) collimated to a 0.6 mm diameter and a CCD detector at a distance of 50 mm from the crystal with a combination of phi and omega scans. A scan width of 0.5 degrees and scan time of 10 seconds were employed. Data collection, reduction, structure solution, and refinement were

o performed using the Bruker Apex2 suite (v2.0-2). All available reflections to 2θmax = 52 were harvested and corrected for Lorentz and polarization factors with Bruker SAINT (v6.45).

Reflections were then corrected for absorption, interframe scaling, and othersystematic errors with SADABS 2004/1. The structures were solved (direct methods) and refined (full – matrix least – squares against F2) with the Bruker SHELXTL package (v6.14-1). All non – hydrogen atoms were refined using anisotropic thermal parameters. Hydrogen atoms were included at ideal positions and were not refined.

2.6.2 Synthesis of Ni(NNS)SPh (1)

Ni(NNS)Cl 0.5 g (0.00167 mol) and sodium thiophenolate (0.66 g, 0.005 mol) were placed in two 250 mL round bottom flasks and 10 mL of dry methanol was added to each flask. After 5 minutes stirring under nitrogen, the sodium thiophenolate solution was added to the Ni(NNS)Cl solution (greenish/brown); the the color of the solution changed to brick red. The solution was left to stir overnight, and then solvent was removed by rotary evaporation. The solid was extracted using CH2Cl2, separated by vacuum filtration and the filtrate solvent was removed by rotary evaporation to obtain a brown/red solid (1.496 g, 0.00400 mol, 80%) of (1).

- Crystallization was done by vapor diffusion of CH2Cl2 and hexane (1:1). FT IR (KBr pellet) (cm

1): 2962, 2921, 1605, 1588, 1575, 1531, 1458, 1432, 1405, 1331, 1259, 1219, 1081, 1021, 956,

902, 873, 783, 735, 688, 642, 615, 531, 474, 449. ESI-MS (positive mode, MeOH, m/z): 396.9

+ + -1 {Ni(NNS)SPh + Na} , 265 {Ni(NNS)} . UV-vis (CH3CN, λ cm ): 424, 308, 244, 207.

2.6.3 Synthesis of Ni(NNS)SPhNO2 (2)

Sodium hydroxide (0.129 g, 0.00323 mol) was dissolved in 10 mL of methanol by heating at reflux for 15 minutes. The solution was then transferred into a round bottom flask containing 4- nitrothiophenol ( 0.5 g, 0.00323 mol) in 10 mL MeOH (an orange solution was formed) which was left to stir for 10 minutes. The solution was then added to a solution of Ni(NNS)Cl (0.3236 g, 0.00108 mol) in 10 mL MeOH under nitrogen. A red orange solution was formed, the solvent was removed by rotary evaporation and the resulting solid was extracted using CH2Cl2 to yield

(2) (1.13 g, 0.00270 mol, 83.3%) as a red powder. Crystallization was done by vapor diffusion

-1 using CH2Cl2 and hexane (1:1 ratio). FT IR (KBR pellet) (cm ): 3096, 2545, 2175, 2111, 1922,

1574, 1497, 1476, 1329, 1179, 1115, 1089, 960, 928, 834, 738, 679, 624, 522, 465. ESI-MS

+ + (positive mode, MeOH, m/z): 684 {(Ni(NNS))2SPhNO2} , 265 {Ni(NNS)} . UV-vis (CH3CN,

λ cm-1): 434, 321, 300, 254, 249.

2.6.4 Synthesis of Ni(NNS)StBut (3)

Ni(NNS)Cl (0.5g , 0.00167 mol) and sodium t-butylthiolate (0.558 g, 0.005 mol) were added to two 500 mL round bottom flasks, 10 mL of dry methanol was added to each flask and the solutions were left to stir under nitrogen. The sodium t-butylthiolate solution was transferred into the Ni(NNS)Cl solution. A black solution was formed which was left for 24 hrs. The solvent was removed by rotary evaporation and the resulting solid was extracted into CH2Cl2, from which 3 was obtained as dark brown powder after removal of solvent (1.245 g, 0.00352 mol, 70.4%).

Crystallization was done by vapor diffusion of CH2Cl2 and Ether (1:1 ratio). FT IR (KBr pellet cm-1): 2960, 2922, 1602, 1588, 1530, 1512, 1456, 1362, 1218, 1158, 1069, 1007, 869, 784, 749,

720, 702, 641, 575, 487, 452. ESI-MS (positive mode, MeOH, m/z): 355 {Ni(NNS)StBuH}+,

+ t + -1 267 {Ni(NNS)} , 618.9 {(Ni(NNS))2S Bu} . UV-vis (CH3CN, λ cm ): 456, 390, 300, 255.

2.6.5 Synthesis of Ni(NNS)’Cl

DTDB (1.5 g, 0.005515 mol) was dissolved in 50 mL of dry MeOH and heated at reflux. A solution of NiCl2·6H20 (2.384g, 0.0101 mol) and 3, 3-dimethydiaminopropane (1.0317 g, 0.0101 mol) in 10 mL of dry methanol was added drop-wise to the DTDB solution and allowed to reflux for 15 minutes under nitrogen. The solution turned from green to brown. The solvent was removed by rotary evaporation resulting in a brown solid that was extracted into CH2Cl2 and filtered to remove unwanted byproducts, giving Ni(NNS)’Cl as a dark green powder (3.076 g,

0.00977 mol, 96.7%). FT IR (KBr pellet, cm-1): 3582, 3386, 2929, 2855, 2815, 2765, 1635,

1586, 1539, 1460, 1375, 1260, 1028, 800, 750, 665. ESI-MS (positive mode, CH2Cl2, m/z): 279

{Ni(NNS)’}+

2.6.6 Synthesis of Ni(NNS)’StBu

Ni(NNS)’Cl (0.5363 g, 0.00171 mol) and sodium t-butylthiolate (0.5743 g, 0.00513 mol) were added into two 500 mL round bottom flasks; 10 mL of methanol was added to each flask. The solutions were left to stir under nitrogen. The sodium t-butylthiolate solution was transferred into the Ni(NNS)’Cl solution. A black solution was formed which was left for 24 hrs and the solvent was removed by rotary evaporation; the resulting solid was extracted into CH2Cl2 to give a black solid of Ni(NNS)’StBu (1.340 g, 0.00364 mol, 70.9%). ESI-MS (positive mode, MeOH, m/z)

279 {Ni(NNS)’}+, 301 {Na +Ni(NNS)’}+ , 391 {Na +Ni(NNS)’StBu}+

2.6.7 Synthesis of Co(deaeba)Cl3 (4).

DTDB (0.5 g, 0.00182 mol) was dissolved in 50 mL of dry MeOH and heated at reflux. A solution of CoCl2·6H20 (0.8684 g, 0.00364 mol) and N, N-dimethylethylenediamine (0.3217 g,

0.00364 mol) in 10 mL of dry methanol was added dropwise to the DTDB solution and allowed to reflux while stirring for 15 minutes under nitrogen. The solution turned from purple to dark green. The solvent was removed by rotary evaporation resulting in a green solid that was extracted into CH3CN and filtered to remove unwanted byproducts, giving 1.123 g (0.00303 mol,

83.2%) of Co(deaeba)Cl3 as a green solid. X-ray quality crystals were obtained by slow evaporation of MeOH. FT IR (KBr pellet cm-1): 2929, 2827, 2219, 2174, 2065, 2012, 1707,

21637, 1587, 1459, 1434, 1355, 1285, 1270, 1255, 1197, 1099, 1048, 981, 906, 820, 746, 689,

661, 611, 579, 549, 508, 475, 425.

2.6.8. Synthesis of Ni(NNS)SC2H4NH2

Ni(NNS)Cl (0.5 g, 0.00166 mol) was dissolved in 10 mL of dry methanol in a 50 ml round bottom flask. NaOH (0.3986 g, 0.00996 mol) was added to a 50 mL round bottom flask containing (0.5662 g, 0.00498 mol) of 2-aminoethanethiolate HCl salt and 10 mL of dry methanol. The mixture containing 2-aminoethanethiolate and NaOH was added to a stirring

Ni(NNS)Cl solution, in which a brown solution was formed. The solvent was removed by rotary evaporation, yielding 0.8 g. Crystallization was done by slow evaporation of MeOH, obtaining brown crystals of (Ni(SNS))2.

2.6.9. Synthesis of Ni(NNS)SC2H4N(CH3)2

NaOH (0.2837 g, 0.00710 mol) in 10 mL MeOH was added into a round bottom flask and 2-

(dimethylamino)ethanethiol HCl (0.5 g, 0.00355 mol) was dissolved in 10 ml MeOH in a second round bottom flask . The NaOH solution was added to the other solution. To this mixture was added Ni(NNS)Cl (0.3557 g, 0.00889 mol) in MeOH, and left for 24 hrs; the color changed to brown red. The solvent was removed by rotary evaporation; 1.22 g yield was obtained.

Crystallization was done by vapor diffusion of CH2Cl2 and ether (1:1). Ni(NNS)Cl crystals were obtained instead of desired product.

2.6.10. Synthesis of Ni(NNS)SEt

Ni(NNS)Cl (0.5 g, 0.00167 mol) was dissolved in 10 ml of MeOH in a 50 mL round bottom flask and left to stir under N2 for 10 minutes. Sodium ethanethiolate (0.4186 g, 0.00498 mol) was added to another 50 mL round bottom flask containing 10 mL of MeOH. After 10 minutes of stirring, the second solution was transferred into the Ni(NNS)Cl solution; the color changed into brown/red. After 24 hrs, the solvent was removed by rotary evaporation, and a yield of 0.8 g

40 brown red solid was obtained. Crystallization was done be vapor diffusion of CH2Cl2 and hexane

(1:1). Ni(NNS)Cl crystals were obtained instead of the desired product.

2.6.11. Synthesis of Ni(NNS)’SPh

Ni(NNS)’Cl (0.5 g, 0.00159 mol) and (0.63 g, 0.0048 mol) of sodium thiophenolate were placed in two 250 mL round bottom flask. Dry methanol (10 mL) was added to each flask and was left for 5 minutes stirring under nitrogen. The sodium thiophenolate solution was transferred to

Ni(NNS)’Cl solution (dark greenish), changing the color of the solution to brick red. The solution was left to stir overnight, and then the solvent was removed by rotary evaporation. After extraction into CH2Cl2, and vacuum filtration and the solvent was removed from the filtrate to obtain 1.68 g brown/red solid. Crystallization was done by layering of CH2Cl2 and hexane, obtaining DTDB crystals.

2.6.12. Synthesis of Ni(NNS)’SPhNO2

NaOH (0.129 g, 0.00409 mol) was dissolved in 10 mL methanol by heating at reflux for 15 minutes. The solution was then added to a solution of (0.5 g, 0.00323 mol) of 4-nitrothiophenol in 10 mL of MeOH. An orange solution was formed which was left to stir for 10 minutes.

Ni(NNS)’Cl (0.3236 g, 0.00108 mol) was then dissolved in 10 mL of MeOH and the orange solution was added under nitrogen. A dark brown solution was formed; the solvent was removed by rotary evaporation and vacuum filtered using CH2Cl2. Product yield of 0.5 g of brown red solid was obtained. Crystallization was done by vapor diffusion of CH2Cl2 and hexane (1:1), obtaining DTDB crystals.

CHAPTER 3

CONCLUSION

We have established that DTDB methodology can be successfully used to synthesize compounds having NiN2S2 coordination. We have characterized three square-planar

{Ni(NNS)(SR)} compounds with N2S2 coordination that serve as potential first-generation synthetic models for the active site of reduced NiSOD. The electrochemical data on these compounds displayed quasireversible redox couples; and the couples between 400 to 1000 mV were assigned to the ligand-based events while the couples greater than the 1000 mV were assigned to the NiIII/II couple. It was found that the thiolate donor on S(1) had effect on the electrochemical potential, since the oxidation potential of compounds might be affected by the

t donor strength of S (1) Bu > Ph > NO2Ph as compound 3 had the lowest potential followed by 1 then 2. After addition of pyrazole, we observed an increase in potential instead of a decrease,

III III/II .- suggesting Ni is not stabilized. The observed Ni couples are not in the range to catalyze O2 disproportionation, but it is not surprising since we do not have amides or 5th ligand on these compounds. Compounds 1-3 exhibited absorption frequencies ranging from 420-460 nm, which were assigned to LMCT by comparison to similar complexes. Future direction would be recommended to synthesize compounds having amide donors so as to compare the effects of the amide in relation to the imine. Also to synthesize compounds with different NN chelates for example, dmap; would also serve as good comparison in studying the effects of different chelates on the electrochemical potentials and SOD activities.

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APPENDIX

Table A1. Crystallography Data

Identification code 1 2 Empirical formula C17 H20 N2 Ni S2 C17 H19 N3 Ni O2 S2 Formula weight 375.18 420.18 Temperature 150(2) K 150(2) K Wavelength 0.71073 Å 0.71073 Å Crystal system Monoclinic Monoclinic Space group P2(1)/n Cc Unit cell dimensions a = 8.3054(4) Å a = 10.8611(13) Å b = 18.2939(9) Å b = 18.6960(13) Å c = 10.8345(5) Å c = 9.0511(7) Å α = 90°. α = 90°. β = 98.592(3)°. β = 92.181(5)°. ϒ = 90°. ϒ = 90°. Volume 1627.70(13) Å3 1836.6(3) Å3 Z 4 4 Density (calculated) 1.531 Mg/m3 1.520 Mg/m3 Absorption coefficient 1.445 mm-1 1.299 mm-1 F(000) 784 872 Crystal size 0.094 x 0.339 x 0.340 mm3 0.074 x 0.390 x 0.602 mm3 Theta range for data collection 2.72 to 26.00°. 3.75 to 26.00°. -10<=h<=10, -22<=k<=22, - -13<=h<=13, -22<=k<=22, - Index ranges 13<=l<=13 11<=l<=10 Reflections collected 19496 16249 Independent reflections 3194 [R(int) = 0.0773] 3404 [R(int) = 0.0215] Completeness to theta = 26.00° 99.80% 99.60% Data / restraints /parameters 3194 / 0 / 201 3404 / 2 / 228 Goodness-of-fit on F2 1.025 0.999 Final R indices [I>2sigma(I)] R1 = 0.0384, wR2 = 0.0850 R1 = 0.0191, wR2 = 0.0442 R indices (all data) R1 = 0.0646, wR2 = 0.0966 R1 = 0.0209, wR2 = 0.0448 Largest diff. peak and hole 0.480 and -0.402 e.Å-3 0.251 and -0.152 e.Å-3

Table A1. Crystallography Data

Identification code 3 4 Empirical formula C15 H24 N2 Ni S2 C11 H15 Cl3 Co N2 S Formula weight 355.19 372.59 Temperature 150(2) K 150(2) K Wavelength 0.71073 Å 0.71073 Å Crystal system Orthorhombic Orthorhombic Space group Iba2 P2(1)2(1)2(1) Unit cell dimensions a = 14.301(3) Å a = 7.3224(15) Å b = 30.535(7) Å b = 10.678(2) Å c = 7.7030(18) Å c = 18.829(4) Å α = 90°. α = 90°. β = 90°. β = 90°. ϒ = 90°. ϒ = 90°. Volume 3363.7(14) Å3 1472.2(5) Å3 Z 8 4 Density (calculated) 1.403 Mg/m3 1.681 Mg/m3 Absorption coefficient 1.394 mm-1 1.834 mm-1 F(000) 1504 756 Crystal size 0.108 x 0.152 x 0.857 mm3 0.177 x 0.232 x 0.391 mm3 Theta range for data collection 3.29 to 26.00°. 3.52 to 26.00° -17<=h<=17, -37<=k<=37, - -9<=h<=8, -13<=k<=13, - Index ranges 9<=l<=9 21<=l<=23 Reflections collected 18816 12689 Independent reflections 3298 [R(int) = 0.0354] 2880 [R(int) = 0.0259] Completeness to theta = 26.00° 99.70% 99.60% Data / restraints /parameters 3298 / 1 / 219 2880 / 0 / 165 Goodness-of-fit on F2 1.086 1.067 Final R indices [I>2sigma(I)] R1 = 0.0463, wR2 = 0.1262 R1 = 0.0325, wR2 = 0.0920 R indices (all data) R1 = 0.0540, wR2 = 0.1332 R1 = 0.0340, wR2 = 0.0929 Largest diff. peak and hole 1.035 and -0.466 e.Å-3 0.983 and -0.587 e.Å-3

Table A1. Crystallography Data

Identification code 5 DTDB (6) Empirical formula C34 H49 Cl3 N6 Ni3 O S3 C14 H10 O2 S2 Formula weight 936.45 274.34 Temperature 150(2) K 150(2) K Wavelength 0.71073 Å 0.71073 Å Crystal system Monoclinic Orthorhombic Space group P2(1)/n Pca2(1) Unit cell dimensions a = 11.1150(8) Å a = 7.9164(13) Å b = 15.5945(11) Å b = 20.551(3) Å c = 23.9537(17) Å c = 15.405(2) Å α= 90°. α= 90°. β= 101.220(4)°. β= 90°. ϒ = 90°. ϒ = 90°. Volume 4072.6(5) Å3 2506.3(7) Å3 Z 4 8 Density (calculated) 1.527 Mg/m3 1.454 Mg/m3 Absorption coefficient 1.759 mm-1 0.414 mm-1 F(000) 1944 1136 Crystal size 0.130 x 0.146 x 0.298 mm3 0.111 x 0.112 x 0.300 mm3 Theta range for data collection 2.28 to 26.00°. 3.25 to 26.00°. -13<=h<=10, -19<=k<=19, - -9<=h<=9, -25<=k<=25, - Index ranges 29<=l<=26 19<=l<=19 Reflections collected 48066 43380 Independent reflections 7994 [R(int) = 0.0462] 4899 [R(int) = 0.0414] Completeness to theta = 26.00° 99.80% 99.60% Data / restraints /parameters 7994 / 0 / 459 4899 / 1 / 325 Goodness-of-fit on F2 0.913 1.06 Final R indices [I>2sigma(I)] R1 = 0.0491, wR2 = 0.1088 R1 = 0.0331, wR2 = 0.0766 R indices (all data) R1 = 0.0745, wR2 = 0.1252 R1 = 0.0399, wR2 = 0.0803 Largest diff. peak and hole 1.566 and -0.694 e.Å-3 0.632 and -0.198 e.Å-3

Table A2.1. Atomic coordinates (x 104) and equivalent isotropic displacement parameters (Å2x 103) for Ni(NNS)SPh (1). U(eq) is defined as one third of the trace of the orthogonalized Uij tensor. ______x y z U(eq) ______C(1) 10163(4) 1703(2) 5941(3) 21(1) C(2) 10674(4) 1028(2) 5543(3) 24(1) C(3) 10398(4) 1842(2) 7232(3) 25(1) C(4) 11083(4) 1315(2) 8070(3) 30(1) C(5) 11547(5) 639(2) 7646(3) 32(1) C(6) 11346(4) 506(2) 6385(3) 29(1) C(7) 5158(4) 867(2) 3169(3) 22(1) C(8) 3981(4) 502(2) 3750(3) 29(1) C(9) 2747(5) 107(2) 3076(4) 34(1) C(10) 2600(5) 71(2) 1779(4) 35(1) C(11) 3719(5) 418(2) 1192(3) 30(1) C(12) 5040(4) 807(2) 1865(3) 22(1) C(13) 6231(4) 1088(2) 1152(3) 25(1) C(14) 8641(5) 1585(2) 620(3) 34(1) C(15) 9285(5) 2339(2) 841(3) 34(1) C(16) 10124(5) 3216(2) 2426(4) 35(1) C(17) 11537(4) 2055(2) 2507(4) 33(1) N(1) 7541(3) 1448(2) 1551(2) 22(1) N(2) 9921(4) 2415(2) 2194(3) 25(1) Ni(1) 8327(1) 1882(1) 3102(1) 21(1) S(2) 6640(1) 1358(1) 4130(1) 25(1) S(1) 9330(1) 2396(1) 4908(1) 29(1)

Table A2.2. Anisotropic displacement parameters (Å2x 103) for {Ni(NNS)SPh} (1). The anisotropic displacement factor exponent takes the form: - 2[ h2 a*2U11 + ... + 2 h k a* b* U12 ] ______U11 U22 U33 U23 U13 U12 ______C(1) 18(2) 24(2) 21(2) -2(1) 2(1) -4(1) C(2) 21(2) 26(2) 23(2) -4(1) 2(2) -3(2) C(3) 22(2) 30(2) 23(2) -4(2) 3(2) 1(2) C(4) 25(2) 43(2) 22(2) -3(2) 2(2) -3(2) C(5) 25(2) 35(2) 33(2) 8(2) -4(2) 2(2) C(6) 22(2) 26(2) 39(2) -5(2) 3(2) -2(2) C(7) 20(2) 23(2) 24(2) 1(1) 4(2) 5(1) C(8) 26(2) 35(2) 26(2) 6(2) 9(2) 5(2) C(9) 26(2) 33(2) 46(2) 9(2) 12(2) 0(2) C(10) 26(2) 30(2) 50(2) -11(2) 4(2) -6(2) C(11) 31(2) 33(2) 26(2) -4(2) 1(2) 3(2) C(12) 21(2) 21(2) 25(2) 2(1) 4(2) 3(1) C(13) 28(2) 28(2) 18(2) -1(1) 2(2) 2(2) C(14) 33(2) 47(2) 23(2) -2(2) 10(2) -6(2) C(15) 38(2) 39(2) 26(2) 2(2) 11(2) -4(2) C(16) 46(3) 28(2) 34(2) 1(2) 13(2) -6(2) C(17) 26(2) 36(2) 39(2) 2(2) 12(2) 2(2) N(1) 24(2) 26(2) 16(1) 1(1) 5(1) 1(1) N(2) 23(2) 28(2) 26(2) 0(1) 6(1) -2(1) Ni(1) 23(1) 22(1) 17(1) 0(1) 4(1) 0(1) S(2) 28(1) 29(1) 19(1) 1(1) 6(1) -1(1) S(1) 40(1) 23(1) 22(1) -2(1) 0(1) -1(1) ______

Table A2.3. Bond lengths [Å] for {Ni(NNS)SPh} (1).

C(1)-C(2) 1.395(5) C(11)-H(11) 0.95 C(1)-C(3) 1.406(4) C(12)-C(13) 1.438(5) C(1)-S(1) 1.762(3) C(13)-N(1) 1.290(4) C(2)-C(6) 1.379(5) C(13)-H(13) 0.95 C(2)-H(2) 0.95 C(14)-C(15) 1.487(5) C(3)-C(4) 1.387(5) C(14)-N(1) 1.479(4) C(3)-H(3) 0.95 C(14)-H(14A) 0.99 C(4)-C(5) 1.393(5) C(14)-H(14B) 0.99 C(4)-H(4) 0.95 C(15)-N(2) 1.489(5) C(5)-C(6) 1.374(5) C(15)-H(15A) 0.99 C(5)-H(5) 0.95 C(15)-H(15B) 0.99 C(6)-H(6) 0.95 C(16)-N(2) 1.492(4) C(7)-C(8) 1.407(5) C(16)-H(16A) 0.98 C(7)-C(12) 1.406(5) C(16)-H(16B) 0.98 C(7)-S(2) 1.739(4) C(16)-H(16C) 0.98 C(8)-C(9) 1.371(5) C(17)-N(2) 1.488(5) C(8)-H(8) 0.95 C(17)-H(17A) 0.98 C(9)-C(10) 1.393(5) C(17)-H(17B) 0.98 C(9)-H(9) 0.95 C(17)-H(17C) 0.98 C(10)-C(11) 1.359(5) N(1)-Ni(1) 1.884(3) C(10)-H(10) 0.95 N(2)-Ni(1) 2.015(3) C(11)-C(12) 1.415(5) Ni(1)-S(2) 2.1408(10) Ni(1)-S(1) 2.2192(10)

Table A2.3. Bond angles [°] for {Ni(NNS)SPh} (1). C(2)-C(1)-C(3) 117.6(3) C(15)-C(14)-H(14A) 110.3 C(2)-C(1)-S(1) 123.3(3) N(1)-C(14)-H(14A) 110.3 C(3)-C(1)-S(1) 119.0(3) C(15)-C(14)-H(14B) 110.3 C(6)-C(2)-C(1) 121.3(3) N(1)-C(14)-H(14B) 110.3 C(6)-C(2)-H(2) 119.3 H(14A)-C(14)-H(14B) 108.6 C(1)-C(2)-H(2) 119.3 C(14)-C(15)-N(2) 108.1(3) C(4)-C(3)-C(1) 120.5(3) C(14)-C(15)-H(15A) 110.1 C(4)-C(3)-H(3) 119.7 N(2)-C(15)-H(15A) 110.1 C(1)-C(3)-H(3) 119.7 C(14)-C(15)-H(15B) 110.1 C(3)-C(4)-C(5) 120.5(3) N(2)-C(15)-H(15B) 110.1 C(3)-C(4)-H(4) 119.7 H(15A)-C(15)-H(15B) 108.4 C(5)-C(4)-H(4) 119.7 N(2)-C(16)-H(16A) 109.5 C(6)-C(5)-C(4) 119.1(3) N(2)-C(16)-H(16B) 109.5 C(6)-C(5)-H(5) 120.5 H(16A)-C(16)-H(16B) 109.5 C(4)-C(5)-H(5) 120.5 N(2)-C(16)-H(16C) 109.5 C(5)-C(6)-C(2) 120.8(3) H(16A)-C(16)-H(16C) 109.5 C(5)-C(6)-H(6) 119.6 H(16B)-C(16)-H(16C) 109.5 C(2)-C(6)-H(6) 119.6 N(2)-C(17)-H(17A) 109.5 C(8)-C(7)-C(12) 117.6(3) N(2)-C(17)-H(17B) 109.5 C(8)-C(7)-S(2) 117.1(3) H(17A)-C(17)-H(17B) 109.5 C(12)-C(7)-S(2) 125.4(3) N(2)-C(17)-H(17C) 109.5 C(9)-C(8)-C(7) 121.7(3) H(17A)-C(17)-H(17C) 109.5 C(9)-C(8)-H(8) 119.1 H(17B)-C(17)-H(17C) 109.5 C(7)-C(8)-H(8) 119.1 C(13)-N(1)-C(14) 115.7(3) C(8)-C(9)-C(10) 120.5(3) C(13)-N(1)-Ni(1) 132.5(2) C(8)-C(9)-H(9) 119.7 C(14)-N(1)-Ni(1) 111.7(2) C(10)-C(9)-H(9) 119.7 C(17)-N(2)-C(15) 111.0(3) C(11)-C(10)-C(9) 119.1(4) C(17)-N(2)-C(16) 108.7(3) C(11)-C(10)-H(10) 120.4 C(15)-N(2)-C(16) 105.7(3) C(9)-C(10)-H(10) 120.4 C(17)-N(2)-Ni(1) 108.1(2) C(10)-C(11)-C(12) 121.7(3) C(15)-N(2)-Ni(1) 105.8(2) C(10)-C(11)-H(11) 119.2 C(16)-N(2)-Ni(1) 117.3(2) C(12)-C(11)-H(11) 119.2 N(1)-Ni(1)-N(2) 86.20(12) C(7)-C(12)-C(11) 119.3(3) N(1)-Ni(1)-S(2) 96.30(9) C(7)-C(12)-C(13) 124.2(3) N(2)-Ni(1)-S(2) 177.20(9) C(11)-C(12)-C(13) 116.5(3) N(1)-Ni(1)-S(1) 178.13(9) N(1)-C(13)-C(12) 128.0(3) N(2)-Ni(1)-S(1) 92.14(9) N(1)-C(13)-H(13) 116 S(2)-Ni(1)-S(1) 85.39(4) C(12)-C(13)-H(13) 116 C(7)-S(2)-Ni(1) 112.30(12) C(15)-C(14)-N(1) 106.9(3) C(1)-S(1)-Ni(1) 108.34(11)

Table A3.1. Atomic coordinates (x 104) and equivalent isotropic displacement parameters (Å2x 103) for {Ni(NNS)SPhNO2} (2). U(eq) is defined as one third of the trace of the orthogonalized Uij tensor. ______x y z U(eq) ______C(1) 4818(2) 3936(1) 8192(2) 25(1) C(2) 5386(2) 4314(1) 9370(2) 32(1) C(3) 4693(2) 4694(1) 10355(2) 40(1) C(4) 3420(2) 4702(1) 10211(3) 41(1) C(5) 2844(2) 4339(1) 9078(2) 33(1) C(6) 3523(2) 3960(1) 8033(2) 26(1) C(7) 2819(2) 3629(1) 6847(2) 27(1) C(8) 2261(2) 3014(1) 4657(2) 34(1) C(9) 2772(2) 3055(1) 3150(2) 32(1) C(10) 3954(2) 1946(1) 3280(3) 45(1) C(11) 4630(2) 2937(2) 1827(2) 50(1) C(12) 7492(2) 3374(1) 3616(2) 27(1) C(13) 7078(2) 4078(1) 3446(2) 33(1) C(14) 8649(2) 3196(1) 3059(2) 32(1) C(15) 9347(2) 3695(1) 2374(3) 37(1) C(16) 8908(2) 4392(1) 2229(2) 37(1) C(17) 7781(2) 4584(1) 2763(3) 38(1) N(1) 3225(1) 3302(1) 5698(2) 25(1) N(2) 4026(2) 2737(1) 3220(2) 28(1) N(3) 9658(2) 4931(1) 1536(3) 53(1) Ni(1) 4828(1) 3094(1) 5090(1) 23(1) O(1) 9341(2) 5551(1) 1531(3) 75(1) O(2) 10619(2) 4736(1) 990(3) 102(1) S(1) 6659(1) 2694(1) 4454(1) 29(1) S(2) 5791(1) 3489(1) 7018(1) 27(1)

Table A3.2. Anisotropic displacement parameters (Å2x 103) for {Ni(NNS)PhNO2}(2). The anisotropic displacement factor exponent takes the form: - 2[ h2 a*2U11 + ... + 2 h k a* b* U12 ] ______U11 U22 U33 U23 U13 U12 ______C(1) 31(1) 20(1) 25(1) 3(1) 8(1) -2(1) C(2) 34(1) 34(1) 29(1) -2(1) 6(1) -10(1) C(3) 50(1) 34(1) 35(1) -11(1) 10(1) -11(1) C(4) 49(1) 34(1) 41(1) -13(1) 17(1) 0(1) C(5) 36(1) 31(1) 33(1) -2(1) 13(1) 1(1) C(6) 31(1) 21(1) 27(1) 3(1) 8(1) 1(1) C(7) 25(1) 27(1) 30(1) 5(1) 7(1) 4(1) C(8) 23(1) 47(1) 34(1) -6(1) 0(1) 1(1) C(9) 28(1) 39(1) 30(1) -3(1) -3(1) 3(1) C(10) 34(1) 37(1) 64(2) -18(1) -5(1) 3(1) C(11) 39(1) 84(2) 25(1) -1(1) 4(1) -8(1) C(12) 22(1) 34(1) 24(1) -6(1) -1(1) 1(1) C(13) 27(1) 38(1) 36(1) -7(1) 11(1) 3(1) C(14) 26(1) 34(1) 35(1) -11(1) 2(1) 6(1) C(15) 20(1) 46(1) 44(1) -14(1) 11(1) 2(1) C(16) 30(1) 38(1) 44(1) -11(1) 14(1) -5(1) C(17) 32(1) 32(1) 49(1) -5(1) 12(1) 2(1) N(1) 24(1) 28(1) 24(1) 2(1) 2(1) -1(1) N(2) 26(1) 34(1) 25(1) -4(1) 4(1) -2(1) N(3) 42(1) 48(1) 72(2) -13(1) 29(1) -8(1) Ni(1) 21(1) 26(1) 22(1) -2(1) 3(1) 1(1) O(1) 76(1) 39(1) 114(2) -8(1) 52(1) -7(1) O(2) 75(2) 62(1) 175(3) -2(2) 90(2) -3(1) S(1) 26(1) 32(1) 28(1) -2(1) 4(1) 5(1) S(2) 23(1) 33(1) 25(1) -4(1) 2(1) 1(1) ______

Table A3.3. Bond lengths [Å] for {Ni(NNS)SPhNO2}(2). C(1)-C(6) 1.409(3) C(10)-H(18B) 0.98 C(1)-C(2) 1.402(3) C(10)-H(18C) 0.98 C(1)-S(2) 1.7413(19) C(11)-N(2) 1.491(3) C(2)-C(3) 1.385(3) C(11)-H(17A) 0.98 C(2)-H(3) 0.95 C(11)-H(17B) 0.98 C(3)-C(4) 1.383(3) C(11)-H(17C) 0.98 C(3)-H(4) 0.95 C(12)-C(13) 1.396(3) C(4)-C(5) 1.362(3) C(12)-C(14) 1.412(3) C(4)-H(5) 0.95 C(12)-S(1) 1.750(2) C(5)-C(6) 1.413(3) C(13)-C(17) 1.377(3) C(5)-H(6) 0.95 C(13)-H(12) 0.95 C(6)-C(7) 1.433(3) C(14)-C(15) 1.365(3) C(7)-N(1) 1.298(3) C(14)-H(13) 0.95 C(7)-H(7) 0.95 C(15)-C(16) 1.392(3) C(8)-N(1) 1.482(3) C(15)-H(16) 0.95 C(8)-C(9) 1.494(3) C(16)-C(17) 1.380(3) C(8)-H(8A) 0.99 C(16)-N(3) 1.454(3) C(8)-H(8B) 0.99 C(17)-H(14) 0.95 C(9)-N(2) 1.485(2) N(1)-Ni(1) 1.8863(16) C(9)-H(9A) 0.99 N(2)-Ni(1) 1.9893(16) C(9)-H(9B) 0.99 N(3)-O(1) 1.209(3) C(10)-N(2) 1.482(3) N(3)-O(2) 1.227(3) C(10)-H(18A) 0.98 Ni(1)-S(2) 2.1320(5) Ni(1)-S(1) 2.2202(6)

Table A3.4. Bond angle [°] for {Ni(NNS)SPhNO2}(2). H(17A)-C(11)- C(6)-C(1)-C(2) 118.13(18) 109.5 H(17B) C(6)-C(1)-S(2) 125.38(16) N(2)-C(11)-H(17C) 109.5 H(17A)-C(11)- C(2)-C(1)-S(2) 116.48(15) 109.5 H(17C) H(17B)-C(11)- C(3)-C(2)-C(1) 120.9(2) 109.5 H(17C) C(3)-C(2)-H(3) 119.6 C(13)-C(12)-C(14) 118.00(19) C(1)-C(2)-H(3) 119.6 C(13)-C(12)-S(1) 124.24(16) C(4)-C(3)-C(2) 120.7(2) C(14)-C(12)-S(1) 117.75(16) C(4)-C(3)-H(4) 119.6 C(17)-C(13)-C(12) 121.0(2) C(2)-C(3)-H(4) 119.6 C(17)-C(13)-H(12) 119.5 C(5)-C(4)-C(3) 119.6(2) C(12)-C(13)-H(12) 119.5 C(5)-C(4)-H(5) 120.2 C(15)-C(14)-C(12) 121.2(2) C(3)-C(4)-H(5) 120.2 C(15)-C(14)-H(13) 119.4 C(4)-C(5)-C(6) 121.2(2) C(12)-C(14)-H(13) 119.4 C(4)-C(5)-H(6) 119.4 C(14)-C(15)-C(16) 119.19(18) C(6)-C(5)-H(6) 119.4 C(14)-C(15)-H(16) 120.4 C(1)-C(6)-C(5) 119.41(19) C(16)-C(15)-H(16) 120.4 C(1)-C(6)-C(7) 124.41(18) C(17)-C(16)-C(15) 121.0(2) C(5)-C(6)-C(7) 116.18(18) C(17)-C(16)-N(3) 119.3(2) N(1)-C(7)-C(6) 127.97(18) C(15)-C(16)-N(3) 119.63(19) N(1)-C(7)-H(7) 116 C(13)-C(17)-C(16) 119.5(2) C(6)-C(7)-H(7) 116 C(13)-C(17)-H(14) 120.2 N(1)-C(8)-C(9) 106.48(16) C(16)-C(17)-H(14) 120.2 N(1)-C(8)-H(8A) 110.4 C(7)-N(1)-C(8) 115.26(17) C(9)-C(8)-H(8A) 110.4 C(7)-N(1)-Ni(1) 132.55(14) N(1)-C(8)-H(8B) 110.4 C(8)-N(1)-Ni(1) 112.16(13) C(9)-C(8)-H(8B) 110.4 C(9)-N(2)-C(10) 110.59(16) H(8A)-C(8)-H(8B) 108.6 C(9)-N(2)-C(11) 107.20(16) N(2)-C(9)-C(8) 108.18(16) C(10)-N(2)-C(11) 107.90(19) N(2)-C(9)-H(9A) 110.1 C(9)-N(2)-Ni(1) 105.86(12) C(8)-C(9)-H(9A) 110.1 C(10)-N(2)-Ni(1) 108.98(13) N(2)-C(9)-H(9B) 110.1 C(11)-N(2)-Ni(1) 116.26(13) C(8)-C(9)-H(9B) 110.1 O(1)-N(3)-O(2) 122.1(2) H(9A)-C(9)-H(9B) 108.4 O(1)-N(3)-C(16) 120.1(2) N(2)-C(10)-H(18A) 109.5 O(2)-N(3)-C(16) 117.8(2) N(2)-C(10)-H(18B) 109.5 N(1)-Ni(1)-N(2) 86.45(7) H(18A)-C(10)- 109.5 N(1)-Ni(1)-S(2) 96.84(5) H(18B) N(2)-C(10)-H(18C) 109.5 N(2)-Ni(1)-S(2) 176.37(5) H(18A)-C(10)- 109.5 N(1)-Ni(1)-S(1) 172.13(5)

H(18C) H(18B)-C(10)- 109.5 N(2)-Ni(1)-S(1) 91.96(5) H(18C) N(2)-C(11)-H(17A) 109.5 S(2)-Ni(1)-S(1) 84.99(2) N(2)-C(11)-H(17B) 109.5 C(12)-S(1)-Ni(1) 110.54(7) C(1)-S(2)-Ni(1) 112.07(7)

Table A4.1. Atomic coordinates (x 104) and equivalent isotropic displacement parameters (Å2x

103) for {Ni(NNS)StBu} (3). U(eq) is defined as one third of the trace of the orthogonalized Uij tensor.

______x y z U(eq) ______Ni(1) 8402(1) 8757(1) 9155(1) 39(1) S(2) 8225(1) 8384(1) 11450(2) 44(1) S(1) 7801(1) 9304(1) 10688(2) 59(1) C(6) 8500(3) 7831(2) 11154(7) 42(1) N(1) 8875(3) 8290(1) 7763(5) 43(1) C(5) 8331(3) 7561(2) 12595(9) 56(1) C(7) 9037(3) 7886(2) 8086(7) 49(1) C(1) 8869(3) 7650(2) 9625(7) 49(1) C(2) 9065(4) 7186(2) 9644(9) 66(2) C(3) 8904(5) 6934(2) 11073(11) 76(2) C(4) 8521(4) 7120(2) 12518(11) 70(2) C(8) 9087(5) 8434(2) 5963(7) 71(2) C(9B) 9360(9) 8895(4) 6013(12) 52(3) N(2) 8638(4) 9157(2) 7108(6) 60(1) C(12) 6522(4) 9245(2) 11039(10) 67(2) C(14B) 6062(15) 9105(11) 9220(40) 152(12) C(15B) 6258(13) 9678(8) 11860(40) 147(12) C(13) 6333(10) 9069(10) 12820(30) 110(9) C(11) 9152(7) 9545(3) 7432(13) 113(3) C(10) 7779(7) 9305(4) 6326(15) 144(5) C(9) 8589(15) 8833(9) 5570(20) 120(8) C(14) 6066(16) 8879(7) 9970(40) 109(8) C(15) 5956(10) 9664(5) 10580(30) 89(5) C(13B) 6170(30) 8835(9) 12210(40) 144(13) ______

Table A4.2. Anisotropic displacement parameters (Å2x 103) for {Ni(NNS)StBu} (3). The anisotropic displacement factor exponent takes the form: - 2[ h2 a*2U11 + ... + 2 h k a* b* U12 ] ______U11 U22 U33 U23 U13 U12 ______Ni(1) 48(1) 44(1) 27(1) 1(1) 3(1) 0(1) S(2) 54(1) 45(1) 32(1) 2(1) 6(1) 0(1) S(1) 72(1) 50(1) 54(1) -9(1) 5(1) -1(1) C(6) 33(2) 44(2) 47(3) 4(2) -6(2) -3(2) N(1) 40(2) 59(2) 29(2) -3(2) 3(2) 1(2) C(5) 44(3) 62(3) 62(3) 11(3) 8(2) -8(2) C(7) 34(2) 64(3) 49(3) -13(2) -3(2) 2(2) C(1) 36(2) 50(3) 60(4) -5(2) -10(2) -3(2) C(2) 47(3) 59(3) 91(5) -15(3) -3(3) 5(2) C(3) 63(4) 43(3) 123(7) 11(3) -3(4) 0(3) C(4) 58(3) 58(3) 94(6) 25(4) 7(3) -5(3) C(8) 94(5) 89(4) 29(3) 1(3) 11(3) 27(4) C(9B) 67(7) 57(6) 31(5) 22(4) 22(5) 13(5) N(2) 72(3) 75(3) 33(2) 19(2) 5(2) -14(2) C(12) 56(3) 74(4) 70(5) -10(3) 4(3) 16(3) C(14B) 74(12) 210(30) 170(20) 70(20) -77(15) -18(15) C(15B) 63(10) 156(18) 220(30) -120(20) -20(14) 43(10) C(13) 33(6) 210(30) 91(14) 69(16) 15(8) 27(11) C(11) 141(8) 108(6) 90(6) 48(5) 7(6) -42(6) C(10) 105(7) 203(11) 124(9) 112(9) -23(6) 6(6) C(9) 85(12) 220(20) 53(9) 61(13) 26(9) 9(13) C(14) 89(13) 83(11) 160(20) -20(12) -57(15) 13(10) C(15) 61(8) 72(8) 134(14) -51(10) -20(9) 27(6) C(13B) 220(40) 111(17) 100(20) 8(13) 10(20) -54(18) ______

Table 4.3. Bond lengths [Å] for Ni(NNS)StBu (3). Ni(1)-N(1) 1.908(4) C(8)-C(9B) 1.461(13) Ni(1)-N(2) 2.024(4) C(9B)-C(9) 1.17(2) Ni(1)-S(2) 2.1178(14) C(9B)-N(2) 1.556(12) Ni(1)-S(1) 2.2195(16) N(2)-C(11) 1.416(10) S(2)-C(6) 1.749(5) N(2)-C(10) 1.440(10) S(1)-C(12) 1.857(6) N(2)-C(9) 1.54(3) C(6)-C(5) 1.403(8) C(12)-C(13) 1.50(2) C(6)-C(1) 1.404(7) C(12)-C(15B) 1.517(17) N(1)-C(7) 1.279(6) C(12)-C(14) 1.53(2) N(1)-C(8) 1.486(7) C(12)-C(15) 1.556(16) C(5)-C(4) 1.374(8) C(12)-C(14B) 1.61(3) C(5)-H(5) 0.95 C(12)-C(13B) 1.62(3) C(7)-C(1) 1.409(8) C(14B)-C(14) 0.90(3) C(7)-H(7) 0.95 C(14B)-C(15) 2.01(4) C(1)-C(2) 1.442(7) C(15B)-C(15) 1.08(3) C(2)-C(3) 1.364(10) C(15B)-C(13) 2.00(4) C(2)-H(2) 0.95 C(13)-C(13B) 0.89(3) C(3)-C(4) 1.365(11) C(11)-H(15A) 0.98 C(3)-H(3) 0.95 C(11)-H(15B) 0.98 C(4)-H(4) 0.95 C(11)-H(15C) 0.98 C(8)-C(9) 1.44(2) C(14)-C(13B) 1.73(4)

t Tables A4.4. angles [°] for {Ni(NNS)S Bu} (3) N(1)-Ni(1)-N(2) 87.4(2) C(15B)-C(12)-C(14) 139.0(11) N(1)-Ni(1)-S(2) 96.30(13) C(13)-C(12)-C(15) 114.0(13) N(2)-Ni(1)-S(2) 174.35(16) C(15B)-C(12)-C(15) 41.0(12) N(1)-Ni(1)-S(1) 177.42(13) C(14)-C(12)-C(15) 104.9(10) N(2)-Ni(1)-S(1) 91.36(16) C(13)-C(12)-C(14B) 129.1(15) S(2)-Ni(1)-S(1) 85.08(6) C(15B)-C(12)-C(14B) 119.6(16) C(6)-S(2)-Ni(1) 112.54(18) C(14)-C(12)-C(14B) 33.3(11) C(12)-S(1)-Ni(1) 112.7(2) C(15)-C(12)-C(14B) 78.9(13) C(5)-C(6)-C(1) 119.8(5) C(13)-C(12)-C(13B) 32.8(14) C(5)-C(6)-S(2) 115.1(4) C(15B)-C(12)-C(13B) 111.3(17) C(1)-C(6)-S(2) 125.1(4) C(14)-C(12)-C(13B) 66.6(15) C(7)-N(1)-C(8) 115.5(5) C(15)-C(12)-C(13B) 126.7(17) C(7)-N(1)-Ni(1) 132.5(4) C(14B)-C(12)-C(13B) 98.8(15) C(8)-N(1)-Ni(1) 112.0(4) C(13)-C(12)-S(1) 110.2(7) C(4)-C(5)-C(6) 120.4(6) C(15B)-C(12)-S(1) 102.8(9) C(4)-C(5)-H(5) 119.8 C(14)-C(12)-S(1) 114.3(10) C(6)-C(5)-H(5) 119.8 C(15)-C(12)-S(1) 113.6(8) N(1)-C(7)-C(1) 128.8(5) C(14B)-C(12)-S(1) 107.6(11) N(1)-C(7)-H(7) 115.6 C(13B)-C(12)-S(1) 117.6(16) C(1)-C(7)-H(7) 115.6 C(14)-C(14B)-C(12) 69(2) C(6)-C(1)-C(7) 124.6(5) C(14)-C(14B)-C(15) 108(4) C(6)-C(1)-C(2) 116.8(5) C(12)-C(14B)-C(15) 49.4(12) C(7)-C(1)-C(2) 118.5(5) C(15)-C(15B)-C(12) 71.5(12) C(3)-C(2)-C(1) 122.0(6) C(15)-C(15B)-C(13) 108.8(19) C(3)-C(2)-H(2) 119 C(12)-C(15B)-C(13) 48.0(10) C(1)-C(2)-H(2) 119 C(13B)-C(13)-C(12) 81(3) C(2)-C(3)-C(4) 119.3(5) C(13B)-C(13)-C(15B) 122(3) C(2)-C(3)-H(3) 120.3 C(12)-C(13)-C(15B) 48.7(10) C(4)-C(3)-H(3) 120.3 N(2)-C(11)-H(15A) 109.5 C(3)-C(4)-C(5) 121.5(6) N(2)-C(11)-H(15B) 109.5 C(3)-C(4)-H(4) 119.2 H(15A)-C(11)-H(15B) 109.5 C(5)-C(4)-H(4) 119.2 N(2)-C(11)-H(15C) 109.5 C(9)-C(8)-C(9B) 47.5(10) H(15A)-C(11)-H(15C) 109.5 C(9)-C(8)-N(1) 110.2(8) H(15B)-C(11)-H(15C) 109.5 C(9B)-C(8)-N(1) 108.4(5) C(9B)-C(9)-C(8) 67.0(12) C(9)-C(9B)-C(8) 65.5(14) C(9B)-C(9)-N(2) 68.4(15) C(9)-C(9B)-N(2) 67.3(13) C(8)-C(9)-N(2) 111.0(13) C(8)-C(9B)-N(2) 109.5(7) C(14B)-C(14)-C(12) 78(3) C(11)-N(2)-C(10) 104.8(7) C(14B)-C(14)-C(13B) 134(3)

C(11)-N(2)-C(9B) 100.4(7) C(12)-C(14)-C(13B) 59.1(12) C(10)-N(2)-C(9B) 120.0(8) C(15B)-C(15)-C(12) 67.5(14) C(11)-N(2)-C(9) 134.0(9) C(15B)-C(15)-C(14B) 118.8(18) C(10)-N(2)-C(9) 80.8(10) C(12)-C(15)-C(14B) 51.7(7) C(9B)-N(2)-C(9) 44.3(8) C(13)-C(13B)-C(12) 66(2) C(11)-N(2)-Ni(1) 117.0(5) C(13)-C(13B)-C(14) 119(3) C(10)-N(2)-Ni(1) 111.9(5) C(12)-C(13B)-C(14) 54.3(13) C(9B)-N(2)-Ni(1) 102.8(4) C(9)-N(2)-Ni(1) 101.7(7) C(13)-C(12)-C(15B) 83.3(17) C(13)-C(12)-C(14) 98.8(17)

Table A5.1. Atomic coordinates ( x 104) and equivalent isotropic displacement parameters (Å2x 103) for {Co(deaeba)Cl3} (4). U(eq) is defined as one third of the trace of the orthogonalized Uij tensor. ______x y z U(eq) ______C(1) 8588(6) 7277(4) 10573(2) 38(1) C(2) 8607(6) 6655(4) 9913(2) 30(1) C(3) 8746(5) 7353(4) 9278(2) 27(1) C(4) 8899(6) 8644(4) 9291(2) 29(1) C(5) 8851(6) 9237(4) 9943(2) 32(1) C(6) 8685(6) 8563(4) 10578(2) 38(1) C(7) 8459(5) 5303(4) 9814(3) 46(1) C(8) 8363(5) 3890(3) 8718(2) 23(1) C(9) 6331(5) 3594(3) 8620(2) 19(1) C(10) 6714(6) 1326(3) 8758(2) 24(1) C(11) 6594(5) 2216(4) 7578(2) 27(1) Cl(1) 2348(2) 207(1) 8082(1) 37(1) Cl(2) 2152(1) 3632(1) 7554(1) 30(1) Cl(3) 2280(1) 2560(1) 9476(1) 29(1) Co(1) 3104(1) 2186(1) 8340(1) 19(1) N(1) 8541(4) 5132(3) 9065(2) 23(1) N(2) 5935(4) 2345(3) 8321(1) 18(1) S(1) 8655(2) 6428(1) 8526(1) 33(1) ______

Table A5.2. Anisotropic displacement parameters (Å2x 103) for {Co(deaba)Cl3} (4). The anisotropic displacement factor exponent takes the form: - 2[ h2 a*2U11 + ... + 2 h k a* b* U12 ] ______U11 U22 U33 U23 U13 U12 ______C(1) 48(3) 43(2) 24(2) 9(2) -7(2) -16(2) C(2) 33(2) 24(2) 32(2) 7(2) -10(2) -7(2) C(3) 24(2) 32(2) 24(2) -1(2) -4(2) 0(2) C(4) 38(2) 24(2) 24(2) 5(2) -6(2) -5(2) C(5) 40(2) 26(2) 31(2) -3(2) -12(2) -3(2) C(6) 46(3) 45(3) 23(2) -7(2) -6(2) -11(2) C(7) 19(2) 23(2) 95(4) -33(2) -29(2) 6(2) C(8) 24(2) 21(2) 24(2) -2(1) -1(1) 1(1) C(9) 20(2) 18(2) 18(2) -2(1) 0(1) 0(1) C(10) 34(2) 18(2) 20(2) 4(1) -3(2) 6(2) C(11) 36(2) 33(2) 12(2) -1(2) 8(1) 0(2) Cl(1) 47(1) 27(1) 36(1) -5(1) -2(1) -10(1) Cl(2) 32(1) 34(1) 23(1) 9(1) -2(1) 5(1) Cl(3) 30(1) 44(1) 14(1) -1(1) 2(1) 6(1) Co(1) 23(1) 22(1) 12(1) 0(1) -1(1) 0(1) N(1) 24(2) 20(2) 25(2) 0(1) -5(1) -2(1) N(2) 24(1) 18(1) 12(1) -2(1) 0(1) 2(1) S(1) 42(1) 29(1) 29(1) 0(1) -2(1) -2(1) ______

Table A5.3. Bond lengths [Å] for {Co(deaba)Cl3}(4) C(1)-C(6) 1.375(6) C(1)-C(2) 1.409(6) C(1)-H(1) 0.95 C(2)-C(3) 1.412(5) C(2)-C(7) 1.459(5) C(3)-C(4) 1.383(5) C(3)-S(1) 1.728(4) C(4)-C(5) 1.383(6) C(4)-H(4) 0.95 C(5)-C(6) 1.400(6) C(5)-H(5) 0.95 C(6)-H(6) 0.95 C(7)-N(1) 1.423(7) C(7)-H(7) 0.95 C(8)-N(1) 1.484(5) C(8)-C(9) 1.532(5) C(8)-H(8A) 0.99 C(8)-H(8B) 0.99 C(9)-N(2) 1.476(4) C(9)-H(9A) 0.99 C(9)-H(9B) 0.99 C(10)-N(2) 1.478(4) C(10)-H(10A) 0.98 C(10)-H(10B) 0.98 C(10)-H(10C) 0.98 C(11)-N(2) 1.487(4) C(11)-H(11A) 0.98 C(11)-H(11B) 0.98 C(11)-H(11C) 0.98 Cl(1)-Co(1) 2.2380(11) Cl(2)-Co(1) 2.2498(10) Cl(3)-Co(1) 2.2573(10) Co(1)-N(2) 2.080(3) N(1)-S(1) 1.718(3)

Table A5.4. Angles [°] for {Co(deaeba)Cl3}(4) C(6)-C(1)-C(2) 118.4(4) N(2)-C(9)-H(9B) 108.5 C(6)-C(1)-H(1) 120.8 C(8)-C(9)-H(9B) 108.5 C(2)-C(1)-H(1) 120.8 H(9A)-C(9)-H(9B) 107.5 C(1)-C(2)-C(3) 119.9(4) N(2)-C(10)-H(10A) 109.5 C(1)-C(2)-C(7) 125.3(4) N(2)-C(10)-H(10B) 109.5 C(3)-C(2)-C(7) 114.8(4) H(10A)-C(10)-H(10B) 109.5 C(4)-C(3)-C(2) 121.2(4) N(2)-C(10)-H(10C) 109.5 C(4)-C(3)-S(1) 125.9(3) H(10A)-C(10)-H(10C) 109.5 C(2)-C(3)-S(1) 112.9(3) H(10B)-C(10)-H(10C) 109.5 C(5)-C(4)-C(3) 118.0(4) N(2)-C(11)-H(11A) 109.5 C(5)-C(4)-H(4) 121 N(2)-C(11)-H(11B) 109.5 C(3)-C(4)-H(4) 121 H(11A)-C(11)-H(11B) 109.5 C(4)-C(5)-C(6) 121.7(4) N(2)-C(11)-H(11C) 109.5 C(4)-C(5)-H(5) 119.2 H(11A)-C(11)-H(11C) 109.5 C(6)-C(5)-H(5) 119.2 H(11B)-C(11)-H(11C) 109.5 C(1)-C(6)-C(5) 120.8(4) N(2)-Co(1)-Cl(1) 108.67(8) C(1)-C(6)-H(6) 119.6 N(2)-Co(1)-Cl(2) 103.98(8) C(5)-C(6)-H(6) 119.6 Cl(1)-Co(1)-Cl(2) 115.36(4) N(1)-C(7)-C(2) 104.5(4) N(2)-Co(1)-Cl(3) 105.55(8) N(1)-C(7)-H(7) 127.7 Cl(1)-Co(1)-Cl(3) 107.86(4) C(2)-C(7)-H(7) 127.7 Cl(2)-Co(1)-Cl(3) 114.77(4) N(1)-C(8)-C(9) 108.8(3) C(7)-N(1)-C(8) 123.2(3) N(1)-C(8)-H(8A) 109.9 C(7)-N(1)-S(1) 118.9(3) C(9)-C(8)-H(8A) 109.9 C(8)-N(1)-S(1) 117.6(2) N(1)-C(8)-H(8B) 109.9 C(9)-N(2)-C(10) 112.2(3) C(9)-C(8)-H(8B) 109.9 C(9)-N(2)-C(11) 112.3(3) H(8A)-C(8)-H(8B) 108.3 C(10)-N(2)-C(11) 109.2(3) N(2)-C(9)-C(8) 115.0(3) C(9)-N(2)-Co(1) 105.3(2) N(2)-C(9)-H(9A) 108.5 C(10)-N(2)-Co(1) 108.4(2) C(8)-C(9)-H(9A) 108.5 C(11)-N(2)-Co(1) 109.4(2) N(1)-S(1)-C(3) 88.77(18)

Table A6.1. Atomic coordinates ( x 104) and equivalent isotropic displacement parameters (Å2x 103) for {Ni(NNS)Cl} (5). U(eq) is defined as one third of the trace of the orthogonalized Uij tensor. ______x y z U(eq) ______C(1) 2060(6) 3468(4) 395(2) 50(1) C(2) 3150(6) 3658(4) 239(3) 55(2) C(3) 4129(6) 3990(4) 623(3) 56(2) C(4) 4011(6) 4109(3) 1185(3) 50(1) C(5) 2907(5) 3919(3) 1354(2) 39(1) C(6) 1895(5) 3617(3) 956(2) 40(1) C(7) 2899(5) 4013(3) 1953(2) 38(1) C(8) 2282(5) 3971(4) 2838(2) 42(1) C(9) 1312(5) 4478(4) 3016(2) 48(1) C(10) -757(6) 4877(4) 2703(2) 53(2) C(11) -350(7) 3416(4) 3010(3) 65(2) C(12) 4714(5) 2213(4) 2519(3) 50(1) C(13) 5651(5) 2415(4) 2239(3) 55(2) C(14) 5529(5) 2287(4) 1663(3) 51(2) C(15) 4456(5) 1972(3) 1366(3) 46(1) C(16) 3475(4) 1756(3) 1632(2) 37(1) C(17) 3600(4) 1866(3) 2220(2) 38(1) C(18) 2368(4) 1464(3) 1271(2) 36(1) C(19) -418(6) 357(4) 1084(3) 55(2) C(20) 336(5) 1043(4) 921(2) 46(1) C(21) -1662(5) 1169(4) 1669(4) 72(2) C(22) -1024(5) -275(3) 1885(3) 48(1) C(23) 5791(4) 1308(3) 3971(2) 34(1) C(24) 6566(5) 697(3) 3795(2) 41(1) C(25) 7617(5) 932(4) 3616(2) 43(1) C(26) 7921(5) 1798(4) 3612(2) 41(1) C(27) 7189(5) 2409(3) 3793(2) 41(1) C(28) 6097(4) 2186(3) 3977(2) 34(1) 71

C(29) 4693(5) 984(3) 4135(2) 44(1) C(30) 2789(6) 873(4) 4402(3) 66(2) C(31) 2288(6) 1259(4) 4850(3) 58(2) C(32) 2031(5) 2583(4) 5302(2) 49(1) C(33) 1020(5) 2387(4) 4332(2) 55(2) C(34) 8840(14) 4185(16) 4820(4) 276(17) Cl(1) -1667(1) 3529(1) 1669(1) 45(1) Cl(2) 253(1) 959(1) 2918(1) 51(1) N(2) 1990(4) 3928(2) 2210(2) 33(1) N(3) 93(4) 4142(3) 2714(2) 38(1) N(4) 1357(4) 1212(2) 1410(2) 34(1) N(5) -665(4) 552(3) 1673(2) 44(1) N(6) 3852(4) 1400(3) 4320(2) 42(1) N(7) 2138(4) 2192(3) 4751(2) 37(1) Ni(1) 314(1) 3770(1) 1942(1) 32(1) Ni(2) 889(1) 1074(1) 2110(1) 32(1) Ni(3) 3615(1) 2558(1) 4449(1) 30(1) O(1) 9228(8) 4738(8) 4463(4) 207(6) S(1) 442(1) 3431(1) 1090(1) 40(1) S(2) 2516(1) 1594(1) 2621(1) 41(1) S(3) 5228(1) 3009(1) 4178(1) 42(1) S(6) 3180(1) 3926(1) 4527(1) 40(1) ______

___

Table A6.2. Anisotropic displacement parameters (Å2x 103) for {Ni(NNS)Cl}(5). The anisotropic displacement factor exponent takes the form: - 2[ h2 a*2U11 + ... + 2 h k a* b* U12 ] ______U11 U22 U33 U23 U13 U12 ______C(1) 73(4) 41(3) 38(3) -2(2) 17(3) 13(3) C(2) 80(5) 45(3) 43(3) -1(3) 23(3) 20(3) C(3) 67(4) 47(3) 61(4) 4(3) 36(3) 18(3) C(4) 58(4) 37(3) 59(4) -2(3) 20(3) 14(3) C(5) 50(3) 26(3) 44(3) -2(2) 17(2) 7(2) C(6) 66(4) 22(2) 31(3) 1(2) 12(2) 12(2) C(7) 44(3) 28(3) 41(3) -4(2) 7(2) 4(2) C(8) 45(3) 50(3) 31(3) -10(2) 6(2) -3(3) C(9) 51(3) 54(4) 41(3) -6(3) 10(3) 0(3) C(10) 65(4) 50(4) 46(3) -6(3) 15(3) 4(3) C(11) 104(5) 48(4) 44(3) 14(3) 20(3) -12(4) C(12) 49(3) 38(3) 56(4) 5(3) -5(3) 1(3) C(13) 32(3) 45(3) 82(5) 17(3) -4(3) -4(3) C(14) 33(3) 47(3) 75(4) 18(3) 12(3) -2(2) C(15) 41(3) 37(3) 62(4) 11(3) 15(3) 0(2) C(16) 32(3) 26(2) 52(3) 8(2) 10(2) 2(2) C(17) 36(3) 21(2) 54(3) 5(2) 3(2) 1(2) C(18) 39(3) 31(3) 40(3) 4(2) 11(2) 1(2) C(19) 55(4) 51(4) 58(4) -2(3) 7(3) -9(3) C(20) 39(3) 52(3) 46(3) -8(3) 3(2) -11(3) C(21) 42(3) 37(3) 131(7) 0(4) -1(4) 10(3) C(22) 37(3) 40(3) 67(4) 0(3) 11(3) -1(2) C(23) 37(3) 30(3) 37(3) -4(2) 14(2) -5(2) C(24) 45(3) 35(3) 48(3) -9(2) 20(2) -3(2) C(25) 43(3) 43(3) 45(3) -12(2) 14(2) 4(2) C(26) 38(3) 48(3) 40(3) 1(2) 17(2) -2(2)

C(27) 42(3) 35(3) 48(3) 9(2) 15(2) -7(2) C(28) 38(3) 29(3) 37(3) -2(2) 12(2) -2(2) C(29) 52(3) 26(3) 60(3) -9(2) 26(3) -9(2) C(30) 61(4) 39(3) 108(6) -12(3) 41(4) -15(3) C(31) 54(4) 40(3) 90(5) -1(3) 41(3) -7(3) C(32) 45(3) 67(4) 38(3) -3(3) 16(2) -1(3) C(33) 32(3) 81(5) 49(3) -5(3) 0(2) 0(3) C(34) 179(14) 590(50) 49(6) -65(13) -7(7) 230(20) Cl(1) 45(1) 37(1) 51(1) 3(1) 1(1) -15(1) Cl(2) 58(1) 48(1) 56(1) -4(1) 32(1) 0(1) N(2) 40(2) 25(2) 33(2) -4(2) 7(2) -1(2) N(3) 38(2) 39(2) 35(2) 2(2) 6(2) -5(2) N(4) 32(2) 28(2) 41(2) -1(2) 6(2) 0(2) N(5) 30(2) 45(3) 56(3) 7(2) 9(2) 0(2) N(6) 43(2) 27(2) 65(3) -5(2) 27(2) -8(2) N(7) 32(2) 37(2) 42(2) -2(2) 10(2) 1(2) Ni(1) 41(1) 21(1) 32(1) 0(1) 3(1) -4(1) Ni(2) 32(1) 24(1) 43(1) 1(1) 12(1) 3(1) Ni(3) 33(1) 25(1) 32(1) -1(1) 9(1) -1(1) O(1) 130(7) 315(15) 157(8) -176(9) -19(6) 105(8) S(1) 56(1) 30(1) 33(1) -6(1) 3(1) 0(1) S(2) 47(1) 34(1) 42(1) -4(1) 10(1) -6(1) S(3) 48(1) 22(1) 62(1) 1(1) 27(1) -4(1) S(6) 47(1) 27(1) 48(1) 2(1) 14(1) 8(1) ______

Table A6.3. Bond lengths [Å] for {Ni(NNS)Cl} (5) C(1)-C(2) 1.369(8) C(21)-H(21B) 0.98 C(1)-C(6) 1.409(7) C(21)-H(21C) 0.98 C(1)-H(1) 0.95 C(22)-N(5) 1.470(7) C(2)-C(3) 1.382(9) C(22)-H(22A) 0.98 C(2)-H(2) 0.95 C(22)-H(22B) 0.98 C(3)-C(4) 1.389(8) C(22)-H(22C) 0.98 C(3)-H(3) 0.95 C(23)-C(28) 1.410(7) C(4)-C(5) 1.397(8) C(23)-C(24) 1.403(7) C(4)-H(4) 0.95 C(23)-C(29) 1.444(7) C(5)-C(6) 1.407(7) C(24)-C(25) 1.370(7) C(5)-C(7) 1.443(7) C(24)-H(24) 0.95 C(6)-S(1) 1.731(6) C(25)-C(26) 1.393(7) C(7)-N(2) 1.289(6) C(25)-H(25) 0.95 C(7)-H(7) 0.95 C(26)-C(27) 1.375(7) C(8)-C(9) 1.466(7) C(26)-H(26) 0.95 C(8)-N(2) 1.477(6) C(27)-C(28) 1.413(7) C(8)-H(8A) 0.99 C(27)-H(27) 0.95 C(8)-H(8B) 0.99 C(28)-S(3) 1.730(5) C(9)-N(3) 1.501(7) C(29)-N(6) 1.286(6) C(9)-H(9A) 0.99 C(29)-H(29) 0.95 C(9)-H(9B) 0.99 C(30)-C(31) 1.435(8) C(10)-N(3) 1.482(7) C(30)-N(6) 1.483(7) C(10)-H(10A) 0.98 C(30)-H(30A) 0.99 C(10)-H(10B) 0.98 C(30)-H(30B) 0.99 C(10)-H(10C) 0.98 C(31)-N(7) 1.479(7) C(11)-N(3) 1.471(7) C(31)-H(31A) 0.99 C(11)-H(11A) 0.98 C(31)-H(31B) 0.99 C(11)-H(11B) 0.98 C(32)-N(7) 1.478(6) C(11)-H(11C) 0.98 C(32)-H(32A) 0.98 C(12)-C(13) 1.381(8) C(32)-H(32B) 0.98 C(12)-C(17) 1.412(7) C(32)-H(32C) 0.98 C(12)-H(12) 0.95 C(33)-N(7) 1.469(6) C(13)-C(14) 1.375(9) C(33)-H(33A) 0.98 C(13)-H(13) 0.95 C(33)-H(33B) 0.98 C(14)-C(15) 1.357(8) C(33)-H(33C) 0.98 C(14)-H(14) 0.95 C(34)-O(1) 1.34(3) C(15)-C(16) 1.405(7) C(34)-H(34A) 1.0426 C(15)-H(15) 0.95 C(34)-H(34B) 1.0464 C(16)-C(17) 1.399(7) C(34)-H(34C) 1.0473 C(16)-C(18) 1.433(7) Cl(1)-Ni(1) 2.2036(14) C(17)-S(2) 1.734(5) Cl(2)-Ni(2) 2.1923(15) C(18)-N(4) 1.294(6) N(2)-Ni(1) 1.865(4)

C(18)-H(18) 0.95 N(3)-Ni(1) 1.999(4) C(19)-C(20) 1.457(8) N(4)-Ni(2) 1.862(4) C(19)-N(5) 1.520(7) N(5)-Ni(2) 2.010(4) C(19)-H(19A) 0.99 N(6)-Ni(3) 1.860(4) C(19)-H(19B) 0.99 N(7)-Ni(3) 2.002(4) C(20)-N(4) 1.488(6) Ni(1)-S(1) 2.1393(14) C(20)-H(20A) 0.99 Ni(2)-S(2) 2.1369(15) C(20)-H(20B) 0.99 Ni(3)-S(3) 2.1402(14) C(21)-N(5) 1.465(7) Ni(3)-S(6) 2.2037(14) C(21)-H(21A) 0.98 O(1)-H(1A) 0.8735

Table A6.4. Angles [°] for {Ni(NNS)Cl} (5) C(2)-C(1)-C(6) 120.7(6) C(26)-C(25)-C(24) 118.9(5) C(2)-C(1)-H(1) 119.6 C(26)-C(25)-H(25) 120.5 C(6)-C(1)-H(1) 119.6 C(24)-C(25)-H(25) 120.5 C(3)-C(2)-C(1) 121.5(6) C(25)-C(26)-C(27) 120.7(5) C(3)-C(2)-H(2) 119.3 C(25)-C(26)-H(26) 119.7 C(1)-C(2)-H(2) 119.2 C(27)-C(26)-H(26) 119.7 C(2)-C(3)-C(4) 119.0(6) C(26)-C(27)-C(28) 121.6(5) C(2)-C(3)-H(3) 120.5 C(26)-C(27)-H(27) 119.2 C(4)-C(3)-H(3) 120.5 C(28)-C(27)-H(27) 119.2 C(3)-C(4)-C(5) 120.4(6) C(27)-C(28)-C(23) 117.1(4) C(3)-C(4)-H(4) 119.8 C(27)-C(28)-S(3) 117.7(4) C(5)-C(4)-H(4) 119.8 C(23)-C(28)-S(3) 125.2(4) C(4)-C(5)-C(6) 120.3(5) N(6)-C(29)-C(23) 128.9(5) C(4)-C(5)-C(7) 116.3(5) N(6)-C(29)-H(29) 115.6 C(6)-C(5)-C(7) 123.4(5) C(23)-C(29)-H(29) 115.5 C(5)-C(6)-C(1) 117.9(5) C(31)-C(30)-N(6) 107.5(5) C(31)-C(30)- C(5)-C(6)-S(1) 125.5(4) 110.2 H(30A) C(1)-C(6)-S(1) 116.6(4) N(6)-C(30)-H(30A) 110.3 C(31)-C(30)- N(2)-C(7)-C(5) 128.4(5) 110.2 H(30B) N(2)-C(7)-H(7) 115.8 N(6)-C(30)-H(30B) 110.2 H(30A)-C(30)- C(5)-C(7)-H(7) 115.8 108.5 H(30B) C(9)-C(8)-N(2) 107.1(4) C(30)-C(31)-N(7) 109.9(5) C(30)-C(31)- C(9)-C(8)-H(8A) 110.3 109.7 H(31A) N(2)-C(8)-H(8A) 110.3 N(7)-C(31)-H(31A) 109.7 C(30)-C(31)- C(9)-C(8)-H(8B) 110.3 109.7 H(31B) N(2)-C(8)-H(8B) 110.3 N(7)-C(31)-H(31B) 109.7 H(31A)-C(31)- H(8A)-C(8)-H(8B) 108.6 108.2 H(31B) C(8)-C(9)-N(3) 108.5(4) N(7)-C(32)-H(32A) 109.5 C(8)-C(9)-H(9A) 110 N(7)-C(32)-H(32B) 109.5 H(32A)-C(32)- N(3)-C(9)-H(9A) 110 109.5 H(32B) C(8)-C(9)-H(9B) 110 N(7)-C(32)-H(32C) 109.5 H(32A)-C(32)- N(3)-C(9)-H(9B) 110 109.5 H(32C) H(32B)-C(32)- H(9A)-C(9)-H(9B) 108.4 109.5 H(32C) N(3)-C(10)-H(10A) 109.5 N(7)-C(33)-H(33A) 109.4

N(3)-C(10)-H(10B) 109.5 N(7)-C(33)-H(33B) 109.5 H(33A)-C(33)- H(10A)-C(10)-H(10B) 109.5 109.5 H(33B) N(3)-C(10)-H(10C) 109.5 N(7)-C(33)-H(33C) 109.5 H(33A)-C(33)- H(10A)-C(10)-H(10C) 109.5 109.5 H(33C) H(33B)-C(33)- H(10B)-C(10)-H(10C) 109.5 109.5 H(33C) N(3)-C(11)-H(11A) 109.4 O(1)-C(34)-H(34A) 116.8 N(3)-C(11)-H(11B) 109.5 O(1)-C(34)-H(34B) 116.8 H(34A)-C(34)- H(11A)-C(11)-H(11B) 109.5 101.3 H(34B) N(3)-C(11)-H(11C) 109.5 O(1)-C(34)-H(34C) 117.4 H(34A)-C(34)- H(11A)-C(11)-H(11C) 109.5 100.8 H(34C) H(34B)-C(34)- H(11B)-C(11)-H(11C) 109.5 100.9 H(34C) C(13)-C(12)-C(17) 120.7(6) C(7)-N(2)-C(8) 116.4(4) C(13)-C(12)-H(12) 119.6 C(7)-N(2)-Ni(1) 132.2(4) C(17)-C(12)-H(12) 119.7 C(8)-N(2)-Ni(1) 111.4(3) C(12)-C(13)-C(14) 121.2(5) C(11)-N(3)-C(10) 109.4(5) C(12)-C(13)-H(13) 119.4 C(11)-N(3)-C(9) 113.0(4) C(14)-C(13)-H(13) 119.4 C(10)-N(3)-C(9) 104.5(4) C(15)-C(14)-C(13) 118.9(5) C(11)-N(3)-Ni(1) 109.6(3) C(15)-C(14)-H(14) 120.5 C(10)-N(3)-Ni(1) 113.6(3) C(13)-C(14)-H(14) 120.5 C(9)-N(3)-Ni(1) 106.6(3) C(14)-C(15)-C(16) 122.0(6) C(18)-N(4)-C(20) 114.7(4) C(14)-C(15)-H(15) 119 C(18)-N(4)-Ni(2) 132.6(4) C(16)-C(15)-H(15) 119 C(20)-N(4)-Ni(2) 112.6(3) C(17)-C(16)-C(15) 119.5(5) C(21)-N(5)-C(22) 108.8(4) C(17)-C(16)-C(18) 123.5(5) C(21)-N(5)-C(19) 113.4(5) C(15)-C(16)-C(18) 117.0(5) C(22)-N(5)-C(19) 104.7(4) C(16)-C(17)-C(12) 117.6(5) C(21)-N(5)-Ni(2) 108.1(4) C(16)-C(17)-S(2) 125.8(4) C(22)-N(5)-Ni(2) 116.1(3) C(12)-C(17)-S(2) 116.5(4) C(19)-N(5)-Ni(2) 105.8(3) N(4)-C(18)-C(16) 128.9(5) C(29)-N(6)-C(30) 114.7(4) N(4)-C(18)-H(18) 115.6 C(29)-N(6)-Ni(3) 133.0(4) C(16)-C(18)-H(18) 115.6 C(30)-N(6)-Ni(3) 112.0(3) C(20)-C(19)-N(5) 108.6(5) C(33)-N(7)-C(31) 111.5(5) C(20)-C(19)-H(19A) 110 C(33)-N(7)-C(32) 108.7(4) N(5)-C(19)-H(19A) 110 C(31)-N(7)-C(32) 106.8(4) C(20)-C(19)-H(19B) 110 C(33)-N(7)-Ni(3) 109.8(3) N(5)-C(19)-H(19B) 110 C(31)-N(7)-Ni(3) 105.3(3) H(19A)-C(19)-H(19B) 108.3 C(32)-N(7)-Ni(3) 114.8(3)

C(19)-C(20)-N(4) 108.1(5) N(2)-Ni(1)-N(3) 86.39(17) C(19)-C(20)-H(20A) 110.1 N(2)-Ni(1)-S(1) 96.57(13) N(4)-C(20)-H(20A) 110.1 N(3)-Ni(1)-S(1) 175.86(13) C(19)-C(20)-H(20B) 110.1 N(2)-Ni(1)-Cl(1) 176.39(13) N(4)-C(20)-H(20B) 110.1 N(3)-Ni(1)-Cl(1) 91.58(12) H(20A)-C(20)-H(20B) 108.4 S(1)-Ni(1)-Cl(1) 85.61(6) N(5)-C(21)-H(21A) 109.5 N(4)-Ni(2)-N(5) 86.57(18) N(5)-C(21)-H(21B) 109.5 N(4)-Ni(2)-S(2) 96.77(13) H(21A)-C(21)-H(21B) 109.5 N(5)-Ni(2)-S(2) 176.50(14) N(5)-C(21)-H(21C) 109.4 N(4)-Ni(2)-Cl(2) 176.87(13) H(21A)-C(21)-H(21C) 109.5 N(5)-Ni(2)-Cl(2) 91.98(14) H(21B)-C(21)-H(21C) 109.5 S(2)-Ni(2)-Cl(2) 84.73(6) N(5)-C(22)-H(22A) 109.5 N(6)-Ni(3)-N(7) 86.32(17) N(5)-C(22)-H(22B) 109.5 N(6)-Ni(3)-S(3) 96.58(13) H(22A)-C(22)-H(22B) 109.5 N(7)-Ni(3)-S(3) 175.87(13) N(5)-C(22)-H(22C) 109.5 N(6)-Ni(3)-S(6) 174.21(15) H(22A)-C(22)-H(22C) 109.5 N(7)-Ni(3)-S(6) 92.10(13) H(22B)-C(22)-H(22C) 109.5 S(3)-Ni(3)-S(6) 85.30(5) C(28)-C(23)-C(24) 120.1(4) C(34)-O(1)-H(1A) 113.5 C(28)-C(23)-C(29) 123.5(4) C(6)-S(1)-Ni(1) 111.91(17) C(24)-C(23)-C(29) 116.4(4) C(17)-S(2)-Ni(2) 112.16(18) C(25)-C(24)-C(23) 121.6(5) C(28)-S(3)-Ni(3) 112.80(17) C(25)-C(24)-H(24) 119.2 C(23)-C(24)-H(24) 119.2

Table A7.1. Atomic coordinates (x 104) and equivalent isotropic displacement parameters (Å2x 103) for DTDB (6). U(eq) is defined as one third of the trace of the orthogonalized Uij tensor. ______x y z U(eq) ______C(1) 3741(3) 9615(1) 10641(1) 23(1) C(2) 4055(3) 9005(1) 10985(2) 30(1) C(3) 4802(3) 8937(1) 11801(2) 38(1) C(4) 5232(4) 9477(1) 12288(2) 40(1) C(5) 4934(3) 10092(1) 11948(2) 34(1) C(6) 4194(3) 10166(1) 11133(2) 26(1) C(7) 3787(3) 8458(1) 8714(1) 22(1) C(8) 3544(3) 7908(1) 8170(2) 27(1) C(9) 4933(3) 7613(1) 7787(2) 32(1) C(10) 6561(3) 7836(1) 7926(2) 32(1) C(11) 6784(3) 8369(1) 8468(2) 26(1) C(12) 5418(3) 8684(1) 8843(1) 24(1) C(13) 8877(3) 4823(1) 3572(2) 32(1) C(14) 8362(3) 5382(1) 3115(2) 30(1) C(15) 8659(4) 5989(1) 3465(2) 39(1) C(16) 9487(4) 6042(2) 4275(2) 49(1) C(17) 10000(4) 5500(2) 4719(2) 48(1) C(18) 9700(3) 4893(2) 4372(2) 40(1) C(19) 8226(3) 7127(1) 724(2) 26(1) C(20) 8417(3) 6534(1) 1190(1) 23(1) C(21) 10018(3) 6258(1) 1250(2) 27(1) C(22) 11395(3) 6563(1) 872(2) 31(1) C(23) 11209(3) 7130(1) 400(2) 33(1) C(24) 9634(3) 7409(1) 327(2) 31(1) C(25) 3921(3) 10832(1) 10834(2) 31(1) C(26) 8588(3) 4163(1) 3271(2) 40(1) C(27) 6626(3) 7481(1) 654(2) 34(1) C(28) 1892(3) 7612(1) 8010(2) 30(1) O(1) 7894(2) 4017(1) 2601(1) 43(1) O(2) 5313(2) 7322(1) 997(1) 43(1) 80

O(3) 3359(2) 10984(1) 10134(1) 36(1) O(4) 597(2) 7763(1) 8373(1) 35(1) S(1) 2816(1) 9729(1) 9588(1) 23(1) S(2) 1996(1) 8826(1) 9213(1) 26(1) S(3) 7358(1) 5278(1) 2080(1) 29(1) S(4) 6610(1) 6194(1) 1712(1) 30(1)

Table A7.2. Anisotropic displacement parameters (Å2x 103) for DTDB (6). The anisotropic displacement factor exponent takes the form: - 2[ h2 a*2U11 + ... + 2 h k a* b* U12 ] ______U11 U22 U33 U23 U13 U12 ______C(1) 16(1) 29(1) 24(1) 1(1) 7(1) 4(1) C(2) 32(1) 29(1) 30(1) 3(1) 3(1) 2(1) C(3) 42(2) 38(2) 34(1) 10(1) 3(1) 4(1) C(4) 42(2) 53(2) 26(1) 4(1) -1(1) 6(1) C(5) 37(2) 40(2) 25(1) -3(1) 1(1) 2(1) C(6) 25(1) 28(1) 25(1) -2(1) 5(1) 3(1) C(7) 19(1) 25(1) 21(1) 4(1) 0(1) 2(1) C(8) 22(1) 28(1) 30(1) -1(1) -1(1) 0(1) C(9) 25(1) 31(1) 42(2) -11(1) 0(1) 4(1) C(10) 23(1) 38(2) 34(1) -9(1) 4(1) 4(1) C(11) 21(1) 32(1) 25(1) 1(1) 1(1) -1(1) C(12) 25(1) 24(1) 21(1) -1(1) 2(1) -2(1) C(13) 29(1) 42(2) 25(1) 5(1) 2(1) -3(1) C(14) 28(1) 40(1) 21(1) -2(1) 3(1) -7(1) C(15) 43(2) 40(2) 35(1) -7(1) -1(1) -5(1) C(16) 48(2) 57(2) 42(2) -24(2) 3(2) -8(1) C(17) 39(2) 77(2) 27(1) -8(2) -1(1) -2(2) C(18) 37(2) 60(2) 21(1) 8(1) 2(1) -1(1) C(19) 24(1) 26(1) 29(1) -1(1) -4(1) 0(1) C(20) 26(1) 23(1) 21(1) -2(1) -2(1) -4(1) C(21) 32(1) 24(1) 25(1) -4(1) 0(1) 2(1) C(22) 28(1) 35(1) 30(1) -4(1) 4(1) 6(1) C(23) 31(1) 35(1) 32(1) 2(1) 6(1) -3(1) C(24) 32(1) 28(1) 33(1) 5(1) 2(1) -4(1) C(25) 33(1) 26(1) 34(1) -3(1) 2(1) 0(1) C(26) 41(2) 39(2) 38(2) 8(1) 2(1) -3(1) C(27) 32(2) 30(1) 41(2) 3(1) -5(1) 0(1) C(28) 25(1) 29(1) 36(1) -2(1) -5(1) 0(1) O(1) 48(1) 37(1) 44(1) 0(1) -5(1) -4(1) O(2) 24(1) 39(1) 65(1) 6(1) 1(1) 0(1) O(3) 38(1) 27(1) 42(1) 3(1) -2(1) 0(1) 82

O(4) 24(1) 40(1) 40(1) -2(1) 1(1) -2(1) S(1) 25(1) 22(1) 23(1) 0(1) 0(1) 5(1) S(2) 19(1) 29(1) 31(1) -6(1) 2(1) 2(1) S(3) 37(1) 24(1) 25(1) 1(1) -5(1) -8(1) S(4) 27(1) 29(1) 34(1) 3(1) 1(1) -5(1) ______

Table A7.3. Bond lengths [Å] for DTDB (6). C(1)-C(2) 1.383(3) C(15)-C(16) 1.413(4) C(1)-C(6) 1.409(3) C(15)-H(15) 0.95 C(1)-S(1) 1.795(2) C(16)-C(17) 1.369(4) C(2)-C(3) 1.395(4) C(16)-H(16) 0.95 C(2)-H(2) 0.95 C(17)-C(18) 1.378(4) C(3)-C(4) 1.384(4) C(17)-H(17) 0.95 C(3)-H(3) 0.95 C(18)-H(18) 0.95 C(4)-C(5) 1.388(4) C(19)-C(24) 1.397(3) C(4)-H(4) 0.95 C(19)-C(20) 1.423(3) C(5)-C(6) 1.393(3) C(19)-C(27) 1.464(3) C(5)-H(5) 0.95 C(20)-C(21) 1.392(3) C(6)-C(25) 1.461(3) C(20)-S(4) 1.783(2) C(7)-C(12) 1.387(3) C(21)-C(22) 1.386(3) C(7)-C(8) 1.419(3) C(21)-H(21) 0.95 C(7)-S(2) 1.782(2) C(22)-C(23) 1.382(3) C(8)-C(9) 1.388(3) C(22)-H(22) 0.95 C(8)-C(28) 1.463(3) C(23)-C(24) 1.377(3) C(9)-C(10) 1.385(3) C(23)-H(23) 0.95 C(9)-H(9) 0.95 C(24)-H(24) 0.95 C(10)-C(11) 1.388(3) C(25)-O(3) 1.208(3) C(10)-H(10) 0.95 C(25)-H(25) 0.95 C(11)-C(12) 1.386(3) C(26)-O(1) 1.207(3) C(11)-H(11) 0.95 C(26)-H(26) 0.95 C(12)-H(12) 0.95 C(27)-O(2) 1.211(3) C(13)-C(18) 1.402(3) C(27)-H(27) 0.95 C(13)-C(14) 1.406(3) C(28)-O(4) 1.208(3) C(13)-C(26) 1.453(4) C(28)-H(28) 0.95 C(14)-C(15) 1.380(3) S(1)-S(2) 2.0495(8) C(14)-S(3) 1.794(2) S(3)-S(4) 2.0523(9)

Table A7.4. Angles [°] for DTDB (6) C(2)-C(1)-C(6) 118.5(2) C(17)-C(16)-C(15) 121.1(3) C(2)-C(1)-S(1) 122.51(18) C(17)-C(16)-H(16) 119.5 C(6)-C(1)-S(1) 119.02(17) C(15)-C(16)-H(16) 119.5 C(1)-C(2)-C(3) 120.8(2) C(16)-C(17)-C(18) 119.5(3) C(1)-C(2)-H(2) 119.6 C(16)-C(17)-H(17) 120.3 C(3)-C(2)-H(2) 119.6 C(18)-C(17)-H(17) 120.3 C(4)-C(3)-C(2) 120.8(2) C(17)-C(18)-C(13) 120.9(3) C(4)-C(3)-H(3) 119.6 C(17)-C(18)-H(18) 119.6 C(2)-C(3)-H(3) 119.6 C(13)-C(18)-H(18) 119.6 C(3)-C(4)-C(5) 118.9(2) C(24)-C(19)-C(20) 119.4(2) C(3)-C(4)-H(4) 120.5 C(24)-C(19)-C(27) 116.9(2) C(5)-C(4)-H(4) 120.5 C(20)-C(19)-C(27) 123.6(2) C(4)-C(5)-C(6) 120.7(2) C(21)-C(20)-C(19) 118.6(2) C(4)-C(5)-H(5) 119.6 C(21)-C(20)-S(4) 122.73(17) C(6)-C(5)-H(5) 119.6 C(19)-C(20)-S(4) 118.57(17) C(5)-C(6)-C(1) 120.3(2) C(22)-C(21)-C(20) 120.3(2) C(5)-C(6)-C(25) 116.6(2) C(22)-C(21)-H(21) 119.9 C(1)-C(6)-C(25) 123.1(2) C(20)-C(21)-H(21) 119.9 C(12)-C(7)-C(8) 118.5(2) C(23)-C(22)-C(21) 121.3(2) C(12)-C(7)-S(2) 122.47(17) C(23)-C(22)-H(22) 119.4 C(8)-C(7)-S(2) 119.02(17) C(21)-C(22)-H(22) 119.4 C(9)-C(8)-C(7) 119.5(2) C(24)-C(23)-C(22) 119.4(2) C(9)-C(8)-C(28) 117.1(2) C(24)-C(23)-H(23) 120.3 C(7)-C(8)-C(28) 123.4(2) C(22)-C(23)-H(23) 120.3 C(10)-C(9)-C(8) 121.8(2) C(23)-C(24)-C(19) 121.0(2) C(10)-C(9)-H(9) 119.1 C(23)-C(24)-H(24) 119.5 C(8)-C(9)-H(9) 119.1 C(19)-C(24)-H(24) 119.5 C(9)-C(10)-C(11) 118.2(2) O(3)-C(25)-C(6) 125.3(2) C(9)-C(10)-H(10) 120.9 O(3)-C(25)-H(25) 117.3 C(11)-C(10)-H(10) 120.9 C(6)-C(25)-H(25) 117.3 C(12)-C(11)-C(10) 121.3(2) O(1)-C(26)-C(13) 125.2(2) C(12)-C(11)-H(11) 119.4 O(1)-C(26)-H(26) 117.4 C(10)-C(11)-H(11) 119.4 C(13)-C(26)-H(26) 117.4 C(11)-C(12)-C(7) 120.7(2) O(2)-C(27)-C(19) 125.2(2) C(11)-C(12)-H(12) 119.6 O(2)-C(27)-H(27) 117.4 C(7)-C(12)-H(12) 119.6 C(19)-C(27)-H(27) 117.4 C(18)-C(13)-C(14) 119.5(2) O(4)-C(28)-C(8) 125.1(2) C(18)-C(13)-C(26) 116.7(2) O(4)-C(28)-H(28) 117.5 C(14)-C(13)-C(26) 123.9(2) C(8)-C(28)-H(28) 117.5 C(15)-C(14)-C(13) 119.5(2) C(1)-S(1)-S(2) 105.43(8) C(15)-C(14)-S(3) 122.0(2) C(7)-S(2)-S(1) 104.72(8) C(13)-C(14)-S(3) 118.49(19) C(14)-S(3)-S(4) 105.33(9)

C(14)-C(15)-C(16) 119.6(3) C(20)-S(4)-S(3) 104.62(8) C(14)-C(15)-H(15) 120.2

C(16)-C(15)-H(15) 120.2