Synthesis and characterization of new silicon-centred tin-dendrimers Si[CH 2CH 2SnR 3] 4. Single-crystal X-ray structure of the tetrahydrofuran adduct of tetrakis[2-(tribromostannyl)ethyl]silane

Abstract

A series of novel first-generation silicon-centred tin dendrimers Si(CH 2CH 2SnR 3) 4 [R = CH 3 ( 3), i Bu ( 4), C CCH 3 ( 5), C 6H 4CH 3-4 ( 6), C 6H 4OCH 3-4 ( 7), (CH 2) 4OCH 2CH 2OCH 3 ( 8), CH 2SiMe 3 ( 9)] was prepared by the reaction of Si(CH 2CH 2SnBr 3) 4 ( 2) with the appropriate Grignard reagent or LiCH 2SiMe 3 in tetrahydrofuran. The new compounds were characterized by multinuclear NMR studies ( 1H, 13C, 119Sn), mass spectrometry (MALDI-TOF, EI) and elemental analyses. The molecular structure of Si[CH 2CH 2SnBr 3(THF) 2] 2[CH 2-CH 2SnBr 3(THF)] 2 ( 2a) was determined by single-crystal X-ray diffraction.