Synthesis and characterization of new di-n-butyl[bis{dimethyl-2-(3-oxo-5-phenyl(4-subtituted)penten-5-ato)malonates}]tin(IV): The crystal structure of di-n-butyl[bis{dimethyl-2-[5-(4-nitrophenyl)-3-oxo-penten-5-ato]malonate}]tin(IV)

The synthesis and characterization of four new di-n-butyl[bis{dimethyl-2-(3-oxo-5-phenyl(4-subtituted)penten-5-ato)malonates}]tin(IV) 2a-2d are reported. Their structures in CDCl3 solution show a distorted octahedral geometry with a trans disposition of the n-butyl substituents. The 119Sn NMR study at low variable-temperature indicates the presence of trans anti- and syn-isomers, and solid-state 13C and 119Sn NMR spectra of compound 2d give also evidence of the isomeric mixture. The X-ray diffraction study of compound 2d at 168 K shows only the trans syn-isomer, where the metal is six-coordinated in a skewed trapezoidal bipyramidal (STB) geometry.