Crystal structure of fac-bis[bis(pyridin-2-yl)methanamine]iron(II) 1,1,3,3-tetracyano-2-(dicyanomethylidene)propane-1,3-diide, [Fe(dipa)2](tcpd)

Abstract

In the title compound, [Fe(C11H11N3)2](C10N6), the FeII cation is coordinated by two bis(pyridin-2-yl)methanamine (dipa) ligands and has crystallographic twofold symmetry. There are deviations from ideal octahedral geometry due to the steric requirements of the ligands. The polynitrile 1,1,3,3-tetracyano-2-(dicyanomethylidene)propane-1,3-diide (tcpd2−) dianion is disordered about an inversion center and is not coordinated to the Fe atom. The anion is not planar but has a propeller shape. In the crystal, weak N—H...N interactions between the amine H atoms of the dipa ligands and two nitrile groups of the anion form an alternating chain of cations and anions related by the C-centering of the unit cell.