Distortion of Crystal Structures of Some Co^III Ammine Complexes. III. Distortion of Crystal Structure of [Co(NH₃)₅NO₂]Cl₂ at Hydrostatic Pressures up to 3.5 GPa

This contribution continues comparative studies on the anisotropy of structural distortion of some Co^III ammine complexes induced by various actions [Boldyreva, Kivikoski & Howard (1997a). Acta Cryst. B53, 394-404; Boldyreva, Kivikoski & Howard (1997b). Acta Cryst. B53, 405-414]. Changes in the cell parameters of (OC-6-22)-pentaamminenitro-N-cobalt(III) dichloride were measured by single-crystal X-ray diffraction at pressures up to 3.5 GPa in a diamond anvil cell (DAC). At several pressures (ambient, 0.24, 0.52, 1.25, 1.91 and 3.38 GPa) a full data collection was carried out, and the atomic coordinates and anisotropic atomic displacement parameters were refined. The anisotropy of structural distortion under pressure was shown to be qualitatively different compared with that on cooling (Boldyreva, Kivikoski & Howard, 1997b). The role of the non-covalent interactions, in particular hydrogen bonds, in the anisotropy of structural distortion is discussed.