0000000000555899
AUTHOR
Claudia Schneider-koglin
Über tetraaryl-methan-analoga in der gruppe 14
Abstract The title compounds have been synthesized by Grignard reactions or pyrolysis of diplumbanes respectively. The crystal structures of m -Tol 4 Pb and Ph 4 Pb (redetermination) have been determined. All eight compounds (Ph/Tol) 4 (Sn/Pb) are S 4 symmetric and contracted along this unique axis. The 13 C-NMR chemical shifts and the couplings 1 J ( 119 Sn/ 207 Pb 13 C) as well depend additively upon the methyl substituents. The ratios 1 K ( 207 Pb 13 C): 1 K ( 119 Sn 13 C) of the reduced coupling constants are all near to 1.61; a comparison with values from the literature for alkyl, alkenyl and alkinyl substituents is given. The ratio δ( 207 Pb):δ( 119 Sn) results in 2.28. IR (700 dow…
Synthesis and structural studies of 2-stannyl-substituted ferrocenylmethylamine and -phosphine derivatives 2-Me2RSnFcCH2Y (RMe, Cl; YNMe2, PPh2, P(O)Ph2; FcC10H8Fe)
Abstract 2-(Trimethylstannyl)ferrocenylmethyldiphenylphosphine, 2-Me3SnFcCH2PPh2 (2a), was synthesized from 2-Me3SnFcCH2NMe2 (1a) and Ph2PH. Compound 2a is oxidized with H2O2 to 2-Me3SnFcCH2P(O)Ph2 (3a). Halogenation of 1a and 2a with Me2SnCl2 and 3a with HCl-diethyl ether yields the organotin monochlorides 2-Me3(Cl)SnFcCH2Y ( 1b , Y = NMe 2 ; 2b , Y = PPh 2 3b , Y = P ( O ) Ph 2 ) . Both crystal structure determinations and multinuclear magnetic resonance studies in solution reveal for 1b–3b molecular structures in which the tin atom approaches a trigonal bipyramidal pentacoordination as a consequence of an intramolecular Y Sn interaction. The donor strength of Y increases in the order PPh2
Über gemischte gruppe 14-gruppe 14-bindungen
Abstract The lead-tin compounds o-Tol6PbSn, o-Tol3PbSnPh3 and Mes3PbSnPh3 have been synthesized from Li and halide precursors in THF/ether at low temperatures. The crystal structures of the S4 symmetric o-Tol4Pb and of the three isomorphous title compounds have been determined (d(SnSn) 2.883 (1), d (PbSn) 2.845 (2), d (PbPb) 2.895 (2), A). The long SnSn distance is in accordance with the Raman data for the pairs of p-Tol6/o-Tol6 substituents (ν(SnSn) 131/123, ν(PbSn) 114/114, ν(PbPb) 105/103 cm−1). The sequence of the 119Sn and 207Pb chemical shifts shows clearly a polarity Pbδ−Snδ+ for all lead-tin compounds investigated. The 1J (119Sn207Pb) and 1J(119Sn119Sn) couplings of identi…