The isolation and crystal structure of the powerful Lewis acid, planar tetrakispyridine cobalt(II), [Co(C 5H 5N) 4] 2+, as its mixed chloride hexafluorophosphate salt

Abstract

The isolation and characterization of [Co(C 5H 5N) 4](Cl)(PF 6)·2C 5H 5N 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, pyridine, water, acetic acid, ozone and ammonium hexafluorophosphate. The structure of [Co(C 5H 5N) 4](Cl)(PF 6)·2C 5H 5N consists of planar [Co(C 5H 5N) 4] 2+ units at the corners of the unit cell. A PF 6 − 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) Å from each cobalt atom. The CoN distance is 2.00(2) Å.