N-Heterocyclic Pincer Dicarbene Complexes of Iron(II): C-2 and C-5 Metalated Carbenes on the Same Metal Center

Six- and five-coordinate Fe(II) complexes
with the pincer ligand 2,6-bis(imidazolylidene)pyridine
(C−N−C), [(C−N−C)Fe(MeCN)3][BPh4]2 and [(C−N−C)FeBr2], respectively, were synthesized. Substitution of
tmeda in [FeCl2(tmeda)]2 by C−N−C gave the six-coordinate {[Fe(C−N−C)(C−N−C*)][FeCl4]}, in which
one of the pincer ligands is bound to the metal via the
2- and 5-imidazole carbons.