Structural Characterization of N ‐Methylpyridoxine (MePN; PN = Vitamin B 6 ) and Its Diorganotin Complexes [SnR 2 (MePN‐H)]I (R = Me, Et, Bu and Ph)

For comparison with the corresponding pyridoxine complexes we have prepared dimethyl‐, diethyl‐, dibutyl‐ and diphenyltin( IV ) complexes of N ‐methylpyridoxine (MePN). The compounds [SnMe 2 (MePN−H)]I ( 1 ), [SnEt 2 (MePN−H)]I ( 2 ), [SnBu 2 (MePN−H)]I ( 3 ) and [SnPh 2 (MePN−H)]I·H 2 O ( 4 ) were isolated and characterized by IR, Raman, Mössbauer, 1 H, 13 C and 119 Sn NMR spectroscopy, and by EI and FAB mass spectrometry. The crystal structures of [HMePN]I and of compounds 1 , 2· 2H 2 O and 3 were determined by X‐ray diffractometry. Their lattices contain dimeric [SnR 2 (MePN−H)] 2 2+ units (R = Me, Et, Bu) in which two bridging‐chelating methylpyridoxinato anions link pentacoordinate Sn atoms with coordination polyhedra closer to square pyramids than to trigonal bipyramids. NMR results show that the dimeric cations persist in (CD 3 ) 2 SO. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)