Coordinating Tectons: Bipyridyl-Terminated Group 8 Alkynyl Complexes

Abstract

The pendant bipyridyl moiety of transition metal σ-acetylide complexes incorporating the 5-ethynyl-2,2′-bipyridine moiety provides a site of chelation for additional metal centers and facile access to multinuclear complexes as model systems for organometallic "molecular wires". The mononuclear complexes [CpRu(CO) 2 (C 2 bpy)] (Cp ) C 5 H 5 , C 5 Me 5 ) and [RuCl(P∩P) 2 (C 2 bpy)] (P∩P ) dppm, dppe) have been synthesized and characterized through spectroscopic means, providing context for the synthesis and spectroscopic characterization of the heterometallic coordination complex [RuCl(dppe) 2 (C 2 bpy-κ 2 -N,N′-PdCl 2 )]. A number of the complexes were further characterized by solid-state X-ray structural determinations. These studies were extended to other metal ligand systems, and the structures of the tris-bidentate ruthenium(II) complex [Ru(bpy) 2 (5-ethynyl-2,2′-bipyridine)](PF 6 ) 2 and gold(I) σ-alkynyl complexes [(PR 3 )Au(C 2 bpy)] (PR 3 ) PEt 3 , PPh 3 ) are reported.

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

“…Careful selection/matching of the metal head group and redox-active moiety can consequently allow for the specific design of complexes in which either of the electrophores dominates the properties of the redox-generated species. For example, complexes functionalised with tetrathiafulvalenyl [158][159][160] or (metallated) pyridyl [117,142,[161][162][163][164][165] derivatives exhibit minimal electronic coupling between the two moieties, with the redox-active functionality generally dominating the redox-generated state. However, moderation of the spin density or charge distribution in such systems has most notably and extensively been explored through functionalisation with a ferrocenyl moiety.…”

Ruthenium Carbon-Rich Group as a Redox-Switchable Metal Coupling Unit in Linear Trinuclear Complexes

“…Coordination of various metals to bipyridinefunctionalized ruthenium acetylides has been reported by several groups, including our group. 20,21,30,31,[76][77][78] Thus, reaction of the previously reported complex 20, 21 1 and 2 with [M II (hfac)2(H2O)2] (M = Cu, Mn) was achieved by displacement of the labile water molecules by the 2,2'-bipyridyl-ligand. 79 More precisely, combinations of equimolar quantities of [M II (hfac)2(H2O)2] and of bipyridine complex 1 or 2 in toluene under mild conditions lead to the precipitation of the desired complex 1Cu or 1Mn and 2Cu or 2Mn.…”

Clusters as ligands: Synthesis, structure and coordination chemistry of ruthenium clusters derived from 4- and 5-ethynyl-2,2′-bipyridine

“…3! heterocycles [9,10], including 5-ethynyl-2,2'-bipyridine [11]. The bi-functional nature of these compounds makes them ideally suited for the construction of multimetallic systems, and 5-ethynyl-2,2'-bipyridine has found application as a linking unit within the Tinkertoy-based construction of multi-metallic frameworks based on monomolecular nodes [12,13].…”