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)

Abstract The synthesis of four new di- n -butyl[bis{dimethyl-2-(3-oxo-5-phenyl(4-subtituted)penten-5-ato)malonates}]tin(IV) 2a – 2d is reported. These complexes have been characterized by 1 H, 13 C, 119 Sn NMR, HMQC, HMBC, infrared spectroscopy and mass spectrometry (FAB). Their structures in CDCl 3 solution show a distorted octahedral geometry with a trans disposition of the n -butyl substituents. The 119 Sn NMR study at low variable-temperature indicates the presence of trans anti - and syn -isomers, and solid-state 13 C and 119 Sn NMR spectra of compound 2d give also evidence of the mixture of trans isomers. 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.