Structural investigations on diorganotin and triorganotin(IV) phosphomycin derivatives

Four new diorganotin(IV), (R = Me, Bu), and triorganotin(IV), (R = Me, Ph), derivatives of the phosphomycin disodium salt antibiotic[(1R, 2S)-1,2-epoxypropylphosphonate] Na-2 have been synthesized and their solid state configuration studied by X-ray crystallography, FT-IR, Mossbauer, UV -Vis spectroscopies. The X-ray diffraction investigation, performed on the bis[trimethyltin(IV)]phosphomycin, showed that the coordination geometry at all the Sn atoms is trigonal bipyramidal. The structure of the complex forms an unusual polymeric zig-zag planar network. The FT-IR and the Sn-119 Mossbauer studies supported the formation of trigonal bipyramidal (Tbp) molecular structures, both in the diorganotin(IV) and triorganotin(IV) derivatives, even if, in the case of diorganotin(IV) derivatives, the tetrahedral structure cannot be a priori excluded. The PO32-group of phosphomycin coordinates the organotin(IV) centers originating a monodimensional polymeric network, as inferred by variable temperature Sn-119 Mossbauer spectroscopy, used to investigate lattice dynamics of the bis-[trimethyltin(IV)] phosphomycin complex. (C) 2006 Elsevier B. V. All rights reserved.