Synthesis, Characterization and Transesterification Activity of Cross-Linked Styrenic Resins Containing the Triphenyltincarboxylate Moiety Spaced by a Dimethylene from the Aromatic Ring

An organotin monomer, triphenyltin 3-(4-styryl)-propionate (TPTSPr) has been synthesized and copolymerized in different ratios with styrene and 1,4-divinylbenzene in order to obtain resins with catalytic activity in transesterification reactions. The resins and a low molecular weight model compound, triphenyltin 3-(4-ethylphenyl)-propionate (TPT-C2-Pr), mimicking the catalytic co-unit, have been characterized by FT-IR and NMR spectroscopy, with particular attention paid to the coordination at tin and how it correlates to the catalytic activity. The activity of both the resins and of the model compound have been tested in a transesterification model reaction between ethyl acetate and primary alcohol. All the resins show catalytic activity that decreases with increasing content of the active co-unit in the resins, owing to the interaction of the active sites among themselves.