Synthesis, Structure, and Asymmetrization of Tri-p-tolylantimony Derivatives of Alpha-Substituted Acetic, Methacrylic, and Crotonic Acids
摘要
The aim of this work was to synthesize tri-p-tolylantimony dicarboxylates containing substituted acetic, methacrylic, and crotonic acids, to study their structure using IR, NMR, and X-ray methods, and to explore the possibility of obtaining asymmetric dicarboxylates with one non-polymerizing carboxylate fragment and one polymerizable fragment. The reaction of tri-p-tolylantimony with H2O2 or t-BuOOH and the corresponding carboxylic acids resulted in the synthesis of derivatives of tri-p-tolylantimony with yields of 57–90%, including saturated dicarboxylates (p-Tol3Sb(O2CCH3)2, p-Tol3Sb(O2CCH2Cl)2, p-Tol3Sb(O2CCHCl2)2, p-Tol3Sb(O2CCCl3)2, p-Tol3Sb(O2CCH2CN)2) and unsaturated dicarboxylates (p-Tol3Sb(O2CC(CH3)=CH2)2, p-Tol3Sb(O2CCH=CHCH3)2). The structures of the obtained compounds were studied using modern physicochemical methods, including NMR and X-ray crystallography with the structural parameter τ, as well as IR spectroscopy with a comparison of the differences in the wavenumbers of the valence vibrations νas(COO) and νs(COO). For the first time, the possibility of synthesizing an asymmetric tri-p-tolylantimony dicarboxylate via a disproportionation reaction was explored, and the equilibrium constant of this reaction was calculated.