Organotin (IV) derivaties of N-maleoylamino acids:Their synthesis and structural elucidation

Abstract

Organotin carboxylates of general formula $R_3SnL$ (1), (2), (4) and (6), $R_2SnL_2$ (5) and ${[(R_2SnL)_2O]_2}$ (3), where L = N-maleoylglycinate, N-maleoyl-$beta$-alaninate and N-maleoylmethioninate, were prepared. The synthesis of these compounds was achieved by either reaction of organotin halides, $R_3SnCl$, with triethylammonium salt of N-maleoylamino acids or/and organotin oxides, $(R_3Sn)_2O$ and $R_2SnO$, with maleamic acid in the presence of triethyl amine. These compounds were characterized by FT-IR, multinuclear NMR ($^1H$, $^{13}C$ and $^{119}Sn$), mass and $^{119m}Sn$ Mössbauer spectroscopy. The geometry around the tin atom is compared both in solution and in solid state. Different literature methods were employed to calculate the C-Sn-C angle in non-coordinating solvents. The mass fragmentation pattern demonstrated the McLafferty rearrangement in compound (6). Salient features of the X-ray structures for (1), (4) and (6) are also given.