Ligand Redox Non‐Innocence in Transition‐Metal σ‐Alkynyl and Related Complexes

Abstract

Transition-metal σ-alkynyl complexes are valuable functional materials that have found application as sructural units in the assembly of polymetallic arrays and large molecular structures, reagents for the transfer, oligomerisation or functionalisation of alkynes, magnetic or optical materials and putative components for use in a future molecular-based electronics platform. Many σ-alkynyl complexes are redoxactive, undergoing facile oxidation (reduction) at moderate potentials to generate radical cations (anions) in which the

Mixed‐Valence Ruthenium Complexes Rotating through a Conformational Robin–Day Continuum

“…Figure 2). The spin-density in trans-[1] Figure 4) is evenly distributed over the molecular backbone with both the bridging ligand (C≡C / C 6 H 4 / C≡C 19 % / 18 % / 19 %) and the metal centers, Ru(dppe)Cp*, (21 % / 21 %) contributing significantly (the large involvement of the bridge atoms in carrying the spin-density supports redox non-innocent description of this ligand in such delocalized arrangements [48,49] ). This solution corresponds to lowest-energy states calculated previously for [1] + and analogues.…”

Redox‐Induced Reversible PP Bond Formation to Generate an Organometallic σ4λ4‐1,2‐Biphosphane Dication

“…This process is unprecedented in that none of the few known oxidatively induced dimerization reactions of metal acetylide complexes have yet been found to be reversible. [27] Work is in progress to investigate further aspects of the chemistry of 4 a,b[PF 6 ] 2 .…”

Syntheses and Structures of Buta-1,3-Diynyl Complexes from “on Complex” Cross-Coupling Reactions

“…The irreversibility of similar diynyl complexes has been noted on previous occasions, 18 and is likely due to intermolecular coupling of the generated diynyl radicals. 66,85 A general scheme on this oxidation dimerization process is depicted in Scheme 2. In contrast to these monometallic buta-1,3-diynyl derivatives, the bimetallic octa-1,3,5,7-tetrayndiyl complex 6 displays one fully reversible oxidation wave (i pa /i pc = 0.98, ∆E p = 74 mV which is comparable with the internal decamethylferrocene reference) and three subsequent, irreversible processes (Table 2).…”