A General Pathway towards NHC ⋅ GaH2(OTf) Adducts – The Key for the Synthesis of NHC‐Stabilized Cationic 13/15 Chain Compounds of Gallium

Abstract

AbstractA general pathway towards NHC (NHC=N‐heterocyclic carbene)‐stabilized galliummonotriflates NHC ⋅ GaH2(OTf) (NHC=IDipp, 1 a; IPr2Me2, 1 b; IMes, 1 c; IDipp=1,3‐bis(2,6‐diisopropylphenyl)‐imidazolin‐2‐ylidene, IPr2Me2=1,3‐bis‐(diisopropyl)‐4,5‐dimethyl‐imidazolin‐2‐ylidene, IMes=1,3‐bis(2,4,6‐trimethylphenyl)‐imidazolin‐2‐ylidene) is reported. Quantum chemical calculations give detailed insight into the underlying reaction pathway. The obtained NHC ⋅ GaH2(OTf) compounds were employed in reactions with donor‐stabilized pnictogenylboranes to synthesize the elusive cationic parent 13/15/13 chain compounds [IDipp ⋅ GaH2ER2E'H2 ⋅ D][OTf] (3 a: D=IDipp, E=P, E’=B, R=H; 3 b: D=NMe3, E=P, E’=B, R=H, 3 c: D=NMe3, E=P, E’=B, R=Ph, 3 d: D=IDipp, E=P, E’=Ga, R=H). Supporting computational studies highlight the electronic features of the products.