THE ISOLATION AND CRUSTAL STRUCTURE OF THE POWERFUL LEWIS-ACID, PLANAR TETRAKISPYRIDINE COBALT(II), [CO(C5H5N)(4)](2+), AS ITS MIXED CHLORIDE HEXAFLUOROPHOSPHATE SALT

The isolation and characterization of [Co(C5H5N)(4)] (Cl)(PF6). 2C(5)H (5)N by single-crystal X-ray diffraction [refined to R = 0.079, R(w) = 0.049] are reported. The crystals were isolated in low yield from the products of the reaction between cobalt(II) acetate tetrahydrate, pyr idine, water, acetic acid, ozone and ammonium hexafluorophosphate. The structure of [Co(C5H5N)(4)](Cl)(PF6). 2C(5)H(5)N consists of planar [ Co(C5H5N)(4)](2+) units at the corners of the unit cell. A PF6- ion is situated at the centre of the unit cell and chloride ions are located at the mid-points of the short edges of the unit cell, 3.176(2) Angst rom from each cobalt atom. The Co-N distance is 2.00(2) Angstrom.