Oxidative halogenation of Sn(II)heteroaryl alkenolates: Formation of unusual trans-dihalo Sn(IV) complexes

Abstract A series of novel tin(IV)-heteroaryl alkenolates of the general formula [Sn(DMOTFP) 2 X 2 ] (3–6, X = F, Cl, Br, I) were prepared by direct oxidative halogenation of the corresponding tin(II) derivative [Sn II (DMOTFP) 2 ] (2) and by cleavage of the carbon-tin bonds in diphenyltin dichloride [Ph 2 SnCl 2 ] by (4,5-dimethyloxazolyl)-1,1,1-trifluoropropen-2-ol, (H-DMOTFP, 1) with a subsequent halide exchange reaction. The molecular structures elucidated in solution (multi-nuclear NMR spectroscopy) and by single crystal X-ray diffraction confirmed the sixfold coordination of the tin(IV) center with a distorted octahedral arrangement of ligands. An unusual centrosymmetric octahedral trans -dihalo configuration was found for the compounds [Sn IV (DMOTFP) 2 X 2 ] (X = Cl, Br, I), while the compound [Sn(DMOTFP) 2 F 2 ] adopted a cis -dihalide configuration.