Vanadium complexes with N-heterocyclic vinylidene ligands

Abstract

Vanadium complexes with N-heterocyclic vinylidene ligands are reported. The vinylidenes can act as 6e− donor ligands, leading to strong metal–carbon interactions.

Bonding and Reactivity in Terminal versus Bridging Arenide Complexes of Thorium Acting as ThII Synthons

“…Inspired by the reaction of the imidazole‐based diazoolefin IDipp=CN 2 [30] with VCl 3 (THF) 3 which resulted in the formation of a vinylidene complex, [31] we investigated the reaction of complex 1 with IDipp=CN 2 targeting the synthesis of a thorium vinylidene. Addition of one equivalent IDipp=CN 2 to a Et 2 O solution of 1 at −40 °C and the reaction mixture was warmed to room temperature for 3 h resulting in an orange reaction mixture and full consumption of the starting material (Figure S33).…”

Bonding and Reactivity in Terminal versus Bridging Arenide Complexes of Thorium Acting as ThII Synthons

“…[28e,29] In an effort to find new routes to actinide alkylidenes, Hayton and co-workers explored the reactivity of diphenylcyclopropene with actinides and reported that ring opening of a thorium cyclopropenyl complex generates a transient thorium carbene that could not be isolated. [28e] Inspired by the reaction of the imidazole-based diazoolefin IDipp = CN 2 [30] with VCl 3 (THF) 3 which resulted in the formation of a vinylidene complex, [31] we investigated the reaction of complex 1 with IDipp = CN 2 targeting the synthesis of a thorium vinylidene. Addition of one equivalent IDipp = CN 2 to a Et 2 O solution of 1 at À 40 °C and the reaction mixture was warmed to room temperature for 3 h resulting in an orange reaction mixture and full consumption of the starting material (Figure S33).…”

Copper Complexes with Diazoolefin Ligands and their Photochemical Conversion into Alkenylidene Complexes

“…The synthesis of such N‐heterocyclic diazoolefins can be achieved by reaction of the corresponding N‐heterocyclic olefins [13] with nitrous oxide [14] . N‐Heterocyclic diazoolefins can act as C‐donor ligands to metal complexes, [11, 12] and it has been shown for vanadium complexes that N 2 loss can lead to the formation of alkenylidene ligands [15] …”

“…[14] N-Heterocyclic diazoolefins can act as C-donor ligands to metal complexes, [11,12] and it has been shown for vanadium complexes that N 2 loss can lead to the formation of alkenylidene ligands. [15] The reaction of [Cu(COD)Cl] 2 (COD = 1,5-cyclooctadiene) with two equivalents of diazoolefin 1 [11b] resulted in the formation of the adduct 2, which could be isolated in 70 % yield (Scheme 2). Utilization of the ionic complex [Cu(CH 3 CN) 4 ](BF 4 ) instead of [Cu(COD)Cl] 2 gave the homoleptic complex 3 in 94 % yield.…”