Structure, reactivity and in crystallo chemistry of group IX and XI organometallic systems

This thesis describes the application of solid-state techniques to the pursuit of catalytically relevant organometallic systems and provides a comparison between the solution and solid-state behaviour of such complexes. Chapter 1 provides a summary of existing research on the solid-state chemistry of organometallic complexes, with particular focus on single-crystal to single-crystal (SC-SC) transformations. Brief introductions to the fundamentals of gold(I) π-alkyne catalysis and group IX pincer complexes are also discussed. Chapter 2 describes the synthesis of a silver(I) [Ag(NBE)(η
2:η2-BArF4)] zwitterion and proposes an equilibrium between a dichloromethane solvent complex and a Ag∙∙∙H–C agostic complex in the solution-state, in contrast to its solid-state behaviour. Investigation into the zwitterion as a source of Ag[BArF4] is also demonstrated by exemplar ligand substitution, single electron redox, and salt metathesis reactions.
Chapter 3 presents the first examples of sequential solid/gas reactivity of a gold(I) π-ethylene complex, enabling the isolation of a variety of new complexes featuring alkene, carbonyl and amine ligands, [(L1)Au(L)][BArF4] (L1 = tris-2-(4,4'-di-tert-butylbiphenyl)phosphine; L = C2H4, CO, NH3, NMe3, NMe2H, isobutylene, C2H4). The H/D exchange of a gold(I) ammonia complex is also reported and solid-state techniques are employed to prevent the solvent induced reactivity observed in the solution. Additionally, in crystallo methodologies and use of a bulky phosphine ligand support the isolation of the first reported gold(I) π-acetylene complex, the isolation of which has thus far been hindered by deleterious solution-state pathways. Chapter 4 builds upon the work presented by Weller on the application of SC-SC techniques to Brookhart’s [(tBuPONOP)Ir(Me)(H)][BArF4] system, by comparing it to the solution and solid-state chemistry of a similar ligand featuring adamantyl substituents, AdPONOP. In the solid-state, SC-SC loss of methane in vacuo is not observed whilst the complex readily liberates methane in solution and SC-SC reaction with H2, highlighting the difference in solution and solid-state behaviour.