Crystal structure of bis[trans-(ethane-1,2-diamine-κ2N,N′)bis(thiocyanato-κN)chromium(III)] tetrachloridozincate from synchrotron data

Abstract

The structure of the title compound, [Cr(NCS)2(C2H8N2)2]2[ZnCl4], has been determined from synchrotron data. In the asymmetric unit, there are four independent halves of the CrIIIcomplex cations, each of which lies on an inversion centre, and one tetrachloridozincate anion in a general position. The CrIIIatoms are coordinated by the four N atoms of two ethane-1,2-diamine (en) ligands in the equatorial plane and two N-bound NCS−anions in atransarrangement, displaying a slightly distorted octahedral geometry with crystallographic inversion symmetry. The Cr—N(en) and Cr—N(NCS) bond lengths range from 2.0653 (10) to 2.0837 (10) Å and from 1.9811 (10) to 1.9890 (10) Å, respectively. The five-membered metalla-rings are in stablegaucheconformations. The [ZnCl4]2−anion has a distorted tetrahedral geometry. The crystal structure is stabilized by intermolecular hydrogen bonds involving the en NH2or CH2groups as donors and chloride ligands of the anion and S atoms of NCS−ligands as acceptors.