Crystal structure of -(1,4,8,11-tetra-aza-cyclo-tetra-decane-κ )bis-(thio-cyanato-κ)chromium(III) bromide from synchrotron X-ray diffraction data.

The crystal structure of the title complex, -[Cr(NCS)(cyclam)]Br (cyclam = 1,4,8,11-tetra-aza-cyclo-tetra-decane, CHN), has been determined from synchrotron X-ray data. The asymmetric unit contains one [Cr(NCS)(cyclam)] cation and one bromide anion. The Cr ion of the complex cation is coordinated by the four N atoms of the cyclam ligand and by two N-coordinating NCS groups in a arrangement, displaying a distorted octa-hedral coordination sphere. The Cr-N(cyclam) bond lengths are in the range 2.075 (3) to 2.081 (3) Å while the average Cr-N(NCS) bond length is 1.996 (16) Å. The macrocyclic cyclam moiety adopts the most stable -V conformation. The crystal structure is stabilized by inter-molecular hydrogen bonds involving the cyclam N-H groups as donor groups, and the bromide anion and the S atom of one of the NCS ligands as acceptor groups.