Synthesis and characterization of new silicon-centred tin-dendrimers Si[CH2CH2SnR3]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 2 CH 2 SnR 3 ) 4 [R = CH 3 ( 3 ), i Bu ( 4 ), C CCH 3 ( 5 ), C 6 H 4 CH 3 -4 ( 6 ), C 6 H 4 OCH 3 -4 ( 7 ), (CH 2 ) 4 OCH 2 CH 2 OCH 3 ( 8 ), CH 2 SiMe 3 ( 9 )] was prepared by the reaction of Si(CH 2 CH 2 SnBr 3 ) 4 ( 2 ) with the appropriate Grignard reagent or LiCH 2 SiMe 3 in tetrahydrofuran. The new compounds were characterized by multinuclear NMR studies ( 1 H, 13 C, 119 Sn), mass spectrometry (MALDI-TOF, EI) and elemental analyses. The molecular structure of Si[CH 2 CH 2 SnBr 3 (THF) 2 ] 2 [CH 2 -CH 2 SnBr 3 (THF)] 2 ( 2a ) was determined by single-crystal X-ray diffraction.