The Structure Study of Triphenylantimony(V) and Triphenylbismuth(V) Derivatives with Some Unsaturated Carboxylic Acids by IR Spectroscopy

The interaction of triphenylantimony (or triphenylbismuth) with carboxylic acids in the presence of peroxides in ether or THF gave 14 triphenylantimony and triphenylbismuth dicarboxylates Ph3M(O2CR)2 with crotonic, cinnamic, m-nitrocinnamic, p-methoxycinnamic, furylacrylic, vinylacetic and sorbic acids. An aqueous solution of hydrogen peroxide (perhydrol with the peroxide concentration up to 45%) or an 0.8 M ether solution, as well as tert-butyl hydro¬peroxide (98%) were used as initial peroxides. Liquid vinylacetic acid was taken in the amount three times as much as peroxide instead of the required double excess. Solid carboxylic acids had solubility similar to the reaction products, and their separation was more difficult, so they were taken in stoichiometric quantities. Product yields were proved to be 40–90%. The composition of the products was confirmed by the elemental analysis data, 1H and 13C NMR spectroscopy. The position of characteristic signals of symmetric and asymmetric valence vibrations of the main functional groups in the IR spectra has been analyzed, and conclusions about monodentate and bidentate binding of me¬tals to carboxylate ligands are drawn from the difference in their values. Monodentate binding has been recorded in most antimony complexes (crotonate, m-nitrocinnamate, p-methoxycinnamate, furlacrylate, sorbate, vinylacetate), as well as in a number of triphenylbismuth complexes (m-nitrocinnamate, p-methoxycinnamate, furlacrylate, vinylacetate). Bidentate or bordering with monodentate binding has been recorded in the case of antimony only in cinnamate, and in the case of bismuth in crotonate, cinnamate, furylacrylate, and sorbate. The position of the peaks of the valence vibrations of C-H, Sb-C, and Bi-C bonds in the studied carboxylate derivatives, as well as in triphenylantimony and triphenylbismuth molecules, has been compared.