Date of Award

2022

Publication Type

Dissertation

Degree Name

Ph.D.

Department

Chemistry and Biochemistry

Keywords

Inorganic chemistry, Main Group, Transition metal

Supervisor

J.M.Rawson

Supervisor

C.Macdonald

Rights

info:eu-repo/semantics/openAccess

Creative Commons License

Creative Commons Attribution 4.0 International License
This work is licensed under a Creative Commons Attribution 4.0 International License.

Abstract

This thesis describes the oxidative addition of 1,2,5,6-tetrathiocins to low valent transition metals and p-block elements. Chapter 1 provides a literature review of tetrathiocin reactivity and the related dithiete chemistry for both the p- and d-block elements. Chapter 2 describes the synthesis of a library of tetrathiocins used extensively through the rest of this thesis alongside the synthesis of a series of group 10 dithiolate complexes through the oxidative addition of tetrathiocins to M2dba3 (M = Pd or Pt) in the presence of the chelating phosphines dppe and dppf to generate complexes of general formula M(dt)(dppe) and M(dt)(dppf) [M = Pd, Pt, dt = benzenedithiolate derivatives]. The coordination chemistry of complexes bearing benzo-15-crown-5-dithiolate ligands, M(15- c-5-bdt)(dppe) and M(15-c-5bdt)(dppf) with Na+ ions was probed through UV-Vis spectroscopy, X-ray diffraction and electrochemical studies. These revealed formation of 1:1 complexes [M(Na-15-c-5-bdt)(dppe)][BPh4] and [M(Na-15-c-5-bdt)(dppf)][BPh4] (M = Pd, Pt). Chapter 3 describes the oxidative addition of tetrathiocins to the Co(I) complex, CpCo(CO)2, generating the 16e- Co(III) complexes, CpCo(dt) and/or the 18e- complexes [CpCo(dt)]2, depending on the nature of the tetrathiocin. In the case of the dimethoxybenzene dithiolate (dmobdt2-) derivative, both monomeric CpCo(dmobdt) and dimeric [CpCo(dmobdt)]2 species could be isolated in the solid state depending upon crystal growth conditions. CpCo(dmobdt) was found to undergo an unusual mechanochemical solid state transformation to the denser [CpCo(dmobdt)]2 phase upon grinding. Chapter 4 describes the synthesis of the benzo-15-crown-5 and benzo-18-crown- 6 dithiolate complexes CpCo(15-c-5-bdt) and CpCo(18-c-6-bdt). In contrast to the group 10 chemistry described in Chapter 2, spectroscopic studies in solution and crystallographic studies in the solid state indicated that CpCo(15-c-5-bdt) was found to coordinate to the alkali metal ions Na+, K+, Rb+ and Cs+ to form 2:1 complexes [A{CpCo(15-c-5- bdt)}2][BPh4] (A = Na, K, Rb, Cs). Chapter 5 describes the one-pot synthesis of a series of substituted nickel(II)dithiolate bipyridine ‘push-pull’ complexes, Ni(bdt)(bpy), via oxidative addition chemistry of tetrathiocins to Ni(COD)2 in the presence of chelating bipyridine ligands. The spectroscopic properties of the visible absorption maxima were sensitive to solvent and substituent effects. Empirical correlations were identified for both the solvatochromic effect and the electronic properties of the functional group attached to the bipyridine ligand. EFISH measurements revealed large molecular hyperpolarizabilities, comparable with previously reported Ni(II) dithiolate/diimine complexes. Chapter 6 examines the oxidative addition chemistry of tetrathiocins to Ge(II) in the form of GeCl2∙dioxane to afford Ge(bdt)2 derivatives. The dimethoxybenzenedithiolato complex, Ge(dmobdt)2 was found to be polymorphic and the phase stability examined through DSC and VT-PXRD studies.

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