CRYSTAL AND MOLECULAR STRUCTURE OF DICHLOROBIS(2-DIMETHYLAMINOETHYL)METHYLAMINECOBALT(II)

The crystal structure of Co(Me3dien)Cl2, in which Mesdien is the ligand bis(2-dimethylaminoethyl)methylamine, has been determined from three-dimensional X-ray data collected by photographic methods. The crystals belong to the space group P21/c with cell dimensions a = 8.389 ± 0.004 Å, b = 29.430 ± 0.010 Å, c = 12.018 ± 0.005 Å, β = 101° 31′ ± 4′. The density of 1.385 g cm-3 calculated for eight formula units in the cell is in agreement with the measured density of 1.38 g cm-3. There are two crystallographically independent but essentially identical molecules in the cell. The structure has been refined by least-squares techniques to a final R factor of 8.2% for the 1567 independent observed reflections. The structure consists of discrete molecules in which cobalt(II) exhibits five-coordination, intermediate in shape between trigonal bipyramidal and square pyramidal and seemingly imposed essentially by the steric requirements of the ligands. A detailed study of the effects of steric repulsions on the coordination geometry is made by comparing the structure of Co(Me3dien)Cl2 and that of a related compound. © 1969, American Chemical Society. All rights reserved.