Tris[bis(1-methyl-1H-imidazol-2-yl)-methanone-κ²N³]iron(II) dichloride 5.5-hydrate, cis-bis[bis(1-methyl-1H-imidazol-2-yl)methanone-&kappa²N²]-dichloroiron(II) (ca 153 K) and di-μ-chloro-bis{[bis(1-methyl-1H-imidazol-2-yl)methanone-&kappa²N³]chloroiron(II)} methanol disolvate (ca 300 K).

The first of the title compounds, [Fe(C9H10N4O)3]Cl2·5.SH2O, is the first structurally characterized homoleptic tris[bis(imidazol-2-yl) ketone]-metal complex to be structurally defined. In the second of the title compounds, [FeCl2(C9H10N4O)2], a pair of monodentate donors supplants one of the bidentate ligands. In the third complex, [Fe2Cl4(C9H10N4O)2]·2CH3OH, a centrosymmetric binuclear compound with a pair of bridging chloride ligands, the introduction of a third chloro ligand results in five-coordination about each of the metal atoms; the environments of the latter are square pyramidal, with a chloro ligand at the apex and the two bidentate arrays about the base of the pyramid. [ABSTRACT FROM AUTHOR]