NHC adducts of tantalum amidohalides: the first example of NHC abnormally coordinated to an early transition metal

Abstract

The reaction of Ta(NMe2)5 with NHC·HBF4 (NHC = IMes and SIMes) leads to new carbene adducts of the mixed TaV amidofluoride, [(NHC)TaF3(NMe2)2]. On the contrary, the reaction of Ta(NMe2)5 with IMes·HCl gives a complex mixture, where [(aIMes)TaCl2(NMe2)3] is identified as one of the products. This is the first example of abnormal NHC coordination to an early transition metal.