Premium
Erste strukturelle Charakterisierung eines 3‐Silaoxetans und 3‐Silathietans im Kristall und in Lösung
Author(s) -
Strohmann Carsten
Publication year - 1995
Publication title -
chemische berichte
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.667
H-Index - 136
eISSN - 1099-0682
pISSN - 0009-2940
DOI - 10.1002/cber.19951280214
Subject(s) - chemistry , crystallography , cyclobutane , crystal structure , ring (chemistry) , nuclear magnetic resonance spectroscopy , steric effects , nmr spectra database , spectroscopy , x ray crystallography , bond length , diffraction , stereochemistry , spectral line , physics , organic chemistry , quantum mechanics , astronomy , optics
First Structural Characterisation of a 3‐Silaoxetane and a 3‐Silathietane in the Crystal and in Solution The 3‐silaoxetane 3,3‐dimethyl‐2,2,4,4‐tetraphenyl‐1‐oxa‐3‐silacyclobutane ( 1 ) and the 3‐silathietane 3,3‐dimethyl‐2,2,4,4‐tetraphenyl‐1‐sila‐3‐thiacyclobutane ( 2 ) were synthesized and studied in the solid state and in solution. The crystal structures of 1 and 2 were investigated by X‐ray diffraction. Furthermore, 1 and 2 were characterized by solid‐state NMR spectroscopy ( 13 C and 29 Si CP/MAS). The cyclobutane ring of 1 is planar with a C‐Si‐C angle of 75.07(9)° and a C‐O‐C angle of 105.3(2)°. 2 crystallizes with a non‐planar cyclobutane ring with a C‐Si‐C angle of 89.00(11)° and a C‐S‐C angle of 93.25(11)°. The Si‐O distance of 241.5(3) pm for 1 and the Si‐S distance of 263.9(3) pm for 2 are shorter than the sum of the van der Waals radii of these atoms. The results obtained by X‐ray diffraction are consistent with those from solid state 13 C‐NMR spectroscopy for 1 and 2. Different 29 Si‐NMR spectra in solution and the solid state indicate unusual electronic or steric effects around the silicon atom of 2 in the solid.