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 Iigand 2,6-bis(imidazolylidene)pyridine (C-N-C), [(C-N-C)Fe(MeCN)3][BPh 4]2 and [(C-N-C)FeBr2], respectively, were synthesized. Substitution of tmeda in [FeCl2(tmeda)]2 by C-N-C gave the sixcoordinate {[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.