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J. Schraml Nguyen-Duc-Chuy V. Chvalovský M. Mgi E. Lippmaa 《Magnetic resonance in chemistry : MRC》1975,7(8):379-385
29Si, 14N 13C and 1H NMR data are presented for a series of homologous (methylethoxysilyl)alkylamines of the type (CH3)3?n(C2H5O)nSi(CH2)mNH2(n=o to 3; m = 1 to 4). The measured 13C and 1H chemical shifts correlate with the total net charges QA on the corressponding atoms, estimated by the Del Re method. 14N and 29Si chemical shifts which do not show simple linear relationships to the charges are found to correlate with the relative basicities of the compounds. The influence of the remote substituent (? NH2 and others) on the 29Si chemical shifts is shown to depend on the number and nature of substituents directly on the silicon atom. Argyments for d-orbital participation in the Si? O bounds are given. The chemical shifts of 29Si, 14N and 13C nuclei are not consistent with the fromation of intramolecular ‘long bonds’ between the solicon and nitrogen atoms in aliphatic silymethylamines. 相似文献
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