Adducts of aluminum and gallium trichloride with a N-heterocyclic carbene and an adduct of aluminum trichloride with a thione

The reactions of AlCl3 and GaCl3 with 1,3,4,5-tetramethylimidazole-2-ylidene in toluene at room temperature affords the 1:1 adducts 5 and 6, respectively. The use of a bulky N-heterocyclic carbene (NHC) in toluene/THF and AlCl3 results in the formation of an imidazolium salt 7 with the tetrachloroaluminate anion. A 1:1 adduct 8 of 1,3,4,5-tetramethylimidazole-2(3H)-thione with AlCl3 is obtained in toluene. The crystal structures of 5(.)0.5C(7)H(8), 7-THF and 8 were determined. ((C) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)