A 1,2,3-triazole-derived pincer-type mesoionic carbene complex of iron(II): carbonyl elimination and hydrosilylation of aromatic aldehydes the concerted reaction with hydrosilane and a base.

Iron complexes bearing 1,2,3-triazol-5-ylidene were synthesized and applied to the reaction with hydrosilane and homogeneous catalytic hydrosilylation of aromatic ketones and aldehydes. Addition of a free carbene to a solution of Fe(CO)Br yielded an octahedral, diamagnetic and cationic iron(II) complex [Fe(1,2,3-triazolylidene)(CO)Br]. Pyrolysis of the dicarbonyl complex eliminated the two CO ligands to form a paramagnetic four-coordinate complex.