Proton Magnetic Resonance and Infrared Studies on Bis(o-phenylenebisdimethylarsine)cobalt(III) Complexes

The pmr and infrared spectra from 4000 to 80 K of several bis(diarsine)cobalt(III) complexes are reported. Deduction of structure (whether cis or trans) has been made on the basis of both types of spectra. Several new cis complexes are reported: [Co(diars)(2)(OAc)(2)]BF4, [Co(diars)(2)CO3]PF6, [(Co(diars)(2)HCO3)(2)HCO3](BF4)(3), [(Co(diars)(2)HCO3)(2)HCO3) (ClO4)(2), Co(diars)(2)(NO3)(2)]ClO4, and [Co(diars)(2)ox]PF6. Experimental frequency ranges from the literature for the bands in the infrared spectra of these acido groups, bound in various different ways, are tabulated. The nature of the bonding in the acetato, thiocyanato, carbonato, and oxalato groups has been determined by comparison of their infrared spectra with the ranges collected from the literature. The dimeric bicarbonato cation is quite unusual in that the bridging unit appears to be a bicarbonato group.