Magnetic and Spectral Studies on Cobalt(II) and Copper(II) Salts of Methylsulfuric, Trifluoromethylsulfuric, and Paratolylsulfuric Acids

Abstract

The compounds Co(CF 3 SO 3 ) 2 , Cu(CF 3 SO 3 ) 2 , Co(CH 3 SO 3 ) 2 , Cu(CH 3 SO 3 ) 2 , Co(p-CH 3 C 6 H 4 SO 3 ) 2 , and Cu(p-CH 3 C 6 H 4 SO 3 ) 2 have been prepared and infrared spectra, electronic spectra, and magnetic susceptibility studies are reported. Electronic spectral and magnetic studies have also been made on Cu(FSO 3 ) 2 and previously published data on Co(FSO 3 ) 2 are reexamined here. The studies indicate that in all salts the metal ions are hexacoordinated by oxygen atoms provided by anions acting as tridentate bridging ligands. The MO 6 skeleton is significantly distorted from regular octahedral geometry for all salts with the possible exceptions of Co(FSO 3 ) 2 , Co(p-CH 3 C 6 H 4 SO 3 ) 2 , and Co(CH 3 SO 3 ) 2 . Values of the spin–orbit coupling constants for the salts, as estimated from the magnetic studies, decrease with increasing anion basicity, suggesting a correlation between basicity and the degree of covalent character in the metal–anion bonds. In the case of the cobalt salts the interelectron repulsion parameter B also seems to decrease with increasing anion basicity.