Síntese e caracterização de novos organometálicos de estanho (iv) com ligantes ditiocarbimatos e sua ação acceleradora na vulcanização de borracha nitrílica

Abstract

This paper describes the synthesis of four new organotin compounds of general formula: (Ph4P)[Sn(Cy)3(RSO2N=CS2)] [Ph4P = tetraphenylphosphonium cation, Cy = cyclohexyl, R = C6H5 (1), 4-ClC6H4 (2), 4-BrC6H4 (3) and 4-IC6H4 (4)]. They were obtained by the reaction between four different potassium N-R-sulfonyldithiocarbimate salts and tricyclohexyltin chloride in methanol, and were isolated as tetraphenylphosphonium salts. The elemental analyses of C, H, N and the data of high-resolution mass spectrometry were consistent with the proposed formulae. The 119Sn NMR spectra and 119Sn Mössbauer spectroscopic data were consistent with the presence of tetracoordinated tin(IV) species in solution and in the solid state. The electrolytic molar conductance and the integration curves in the 1H NMR spectra are in accord with the 1:1 proportion between the tetraphenylphosphonium cations and the complex anions. The activity of the new compounds in the vulcanization of nitrile rubber was evaluated and the results were compared to those achieved with the commercial accelerators: N-tert-butyl-2-benzothiazolesulfenamide (TBBS), tetramethylthiuram disulfide (TMTD) and zinc diethyldithiocarbamate (ZEDC).