Synthesis and structural studies of diorganotin iminodiacetates

Abstract

The compounds of formula HN(CH 2CO 2) 2SnR 2 with R  CH 3 or n-C 4H 9 have been synthesised. The crystal structure of the dimethyltin compound is reported, along with some 1H, 13C and IR spectroscopic data for both the dimethyl and di-n-butyl compounds. The crystals are monoclinic, space group P2 1/ n, a = 10.1912(6), b = 7.0715(4), c = 14.9713(8) Å, β = 108.540(10)°, V = 1022.94 Å 3, Z = 4, D calc = 1.934 Mg m −3, μ = 2.46 mm −1, final R = 2.1% for 1174 significant observed reflections. The complex crystallises as a dimer, with a seven-coordinate distorted pentagonal bipyramidal structure around the two tin atoms, the methyl groups occupying the apical positions. The ligand behaves as a planar tridentate via the imine nitrogen and oxygen atoms from each of the two carboxylate groups. The sixth position in the coordination sphere is taken up by the oxygen atom of a coordinated water molecule while the seventh site is filled by a shared oxygen from the other organotin moiety in the dimer. The bridging oxygens are each coordinated to both tin atoms. The structure of the dibutyltin complex is believed to be the same as that of the dimethyltin complex.