Crystal structure ofcis-dichlorido(1,4,8,11-tetraazacyclotetradecane-κ4N)chromium(III) (oxalato-κ2O1,O2)(1,4,8,11-tetraazacyclotetradecane-κ4N)chromium(III) bis(perchlorate) from synchrotron data

Abstract

In the asymmetric unit of the title compound, [CrCl2(C10H24N4)][Cr(C2O4)(C10H24N4)](ClO4)2(C10H24N4= 1,4,8,11-tetraazacyclotetradecane, cyclam; C2O4= oxalate, ox), there are two independent halves of the [CrCl2(cyclam)]+and [Cr(ox)(cyclam)]+cations, and one perchlorate anion. In the complex cations, which are completed by application of twofold rotation symmetry, the CrIIIions are coordinated by the four N atoms of a cyclam ligand, and by two chloride ions or one oxalate bidentate ligand in acisarrangement, displaying an overall distorted octahedral coordination environment. The Cr—N(cyclam) bond lengths are in the range of 2.075 (5) to 2.096 (4) Å while the Cr—Cl and Cr—O(ox) bond lengths are 2.3358 (14) and 1.956 (4) Å, respectively. Both cyclam moieties adopt thecis-V conformation. The slightly distorted tetrahedral ClO4−anion remains outside the coordination sphere. The supramolecular architecture includes N—H...O and N—H...Cl hydrogen bonding between cyclam NH donor groups, O atoms of the oxalate ligand or ClO4−anions and one Cl ligand as acceptors, leading to a three-dimensional network structure.