ISSN:
1434-1948
Keywords:
β-Donor bonds
;
Silicon
;
Electrostatic interactions
;
Negative hyperconjugation
;
Chemistry
;
General Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
The compounds Cl2Si(ONMe2)2 and Cl2Ge(ONMe2)2 were prepared by the reaction of the appropriate tetrachlorides with N,N-dimethylhydroxylamine in the presence of 2,6-lutidine as an auxiliary base. The compounds were obtained as crystalline solids and characterised by elemental analysis, IR and NMR spectroscopy (nuclei 1H, 13C, 15N, 17O, and 29Si). Their molecular structures were determined by single-crystal X-ray diffraction. The compounds are isostructural and both show the presence of weak secondary bonds between the nitrogen and silicon centres (β-donor bonds), as is indicated by the small angles SiON [102.8(1) and 103.7(1)°] and GeON [102.0(1)°], and the distances Si···N (2.438 and 2.450 Å) and Ge···N (2.519 and 2.520 Å). The conformation is anti-gauche in both compounds (one O-Si-O-N torsion angle being about 180°, the other 60°), but the strength of the β-donor interaction is not significantly affected by the different anti-substituents at the nitrogen centres, although such behaviour was expected from earlier studies carried out on ClH2SiONMe2. The β-donor interactions are also weaker than those found in ClH2SiONMe2.
Additional Material:
2 Ill.
Type of Medium:
Electronic Resource
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