Date of Award

1-1-2019

Publication Type

Doctoral Thesis

Degree Name

Ph.D.

Department

Chemistry and Biochemistry

Keywords

Coordination, Inorganic Chemistry, Lewis Acids, Main Group Chemistry, Pincer Ligands, Triels, Tetrels, Pnictogens

Supervisor

Charles L. B. Macdonald

Rights

info:eu-repo/semantics/openAccess

Abstract

2,6-bis(benzimidazol-2-yl)pyridine derivative (G-BZIMPY, G = NBn, N(3,5-CF3)Bn, N-allyl and O) have been used as pincer ligands to coordinate and isolate various group 13-15 complexes. For Group 13, treatment of G-BZIMPY with two equivalents of GaCl3 results in the self-ionization products [G-BZIMPYGaCl2][GaCl4]. This Ga(III) complex can be reduced to a Ga(I) centre using K2[Fe(CO)4] as a reducing agent to result in the Ga(I) complex [(NBn-BZIMPY)(Cl)Ga–Fe(CO)4] (Chapter 2).

Group 14 complexes of G-BZIMPY have been synthesized in a similar fashion through the self-ionization reactions of G-BZIMPY with two equivalents of MCl2 (M = Ge, Sn) to yield [G-BZIMPYMCl][MCl3]. Attempts to reduce these complexes into the M(0) centre were not successful. Other reactivities and UV-vis studies are detailed in this dissertation (Chapter 3). Comparison of group 13 and 14 complexes of G-BZIMPY to complexes of the structurally similar bis(imino)pyridine (DIMPY) are studied and reveal G-BZIMPY as a stronger donor than DIMPY for group 13 coordination. For group 15 elements, treatment of PnCl3 (Pn = P, As, Sb) with G-BZIMPY does not yield any reactivity, however, the addition of TMS-OTf (Trimethylsilyl trifluoromethanesulfonate) results in the isolation of [G-BZIMPYPnCl][OTf]2 (Chapter 4).

In-addition, a tetradentate ligand tris((1-ethyl-benzoimidazol-2-yl)methyl)amine (BIMEt3) has been investigated. A series of cationic complexes involving a pnictogen(III) (Pn = P, As, Sb) centre coordinated to BIMEt3 have been synthesized and comprehensively characterized. Oxidation of [P(BIMEt3)]3+ with XeF2 provides access to [PF2(BIMEt3)]3+ representing the first structurally characterized example of a phosphorus(V) centred trication (Chapter 5). Attempts to synthesize an anionic carbon(0) are detailed in chapter 6. Although obtaining an anionic carbon(0) was not successful, it lead to a series of interesting compounds and results. Compounds containing carbon centre behave differently than their heavier group-14 analogues of the same bidentate anionic bisphosphine ligand.

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