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 ][BPh 4 ] 2 and [(C−N−C)FeBr 2 ], respectively, were synthesized. Substitution of tmeda in [FeCl 2 (tmeda)] 2 by C−N−C gave the six-coordinate {[Fe(C−N−C)(C−N−C*)][FeCl 4 ]}, in which one of the pincer ligands is bound to the metal via the 2- and 5-imidazole carbons.