No abstract

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.

The molecular structure and charge density distribution in the crystals of triphenylantimony bis[(2E)-3-phenylprop-2-enoate] [Ph 3 Sb(O 2 CCH=CHPh) 2 ] and triphenylantimony bis[(2E)-3-(3-nitrophenyl)prop-2-enoate] benzene solvate [Ph 3 Sb(O 2 CCH=CHC 6 H 4 NO 2 -m) 2 ÁC 6 H 6 ]derived from the high-resolution single-crystal X-ray diffraction data at 100 K are reported together with DFT calculations of these molecules. The nature of the chemical bonds and delocalization of electron density in carboxylate ligands was investigated. The intramolecular SbÁÁÁO interactions as well as intermolecular pÁÁÁp, HÁÁÁp and OÁÁÁp ones and their energy are discussed.

Triphenylbismuth dicrotonate Ph 3 Bi(O 2 CCH=CHCH 3 ) 2 in benzene solution in the presence of 2-methyl-2-nitrosopropane decomposes in light. The phenyl radicals formed as the result of Ph 3 Bi(O 2 CCH=CHCH 3 ) 2 decomposition are confirmed by the spin-trapping method; they can initiate the methylmethacrylate polymerization at room temperature. In the absence of light the decomposition has not been observed.Кeywords: electron paramagnetic resonance, triphenylbismuth dicrotonate, 2-methyl-2nitrosopropane.