NMR study of organosilicon compounds. III—Silicon‐29, nitrogen‐14, carbon‐13 and proton NMR spectra of silylakylamines

Abstract 29 Si, 14 N 13 C and 1 H NMR data are presented for a series of homologous (methylethoxysilyl)alkylamines of the type (CH 3 ) 3− n (C 2 H 5 O) n Si(CH 2 ) m NH 2 ( n =o to 3; m = 1 to 4). The measured 13 C and 1 H chemical shifts correlate with the total net charges Q A on the corressponding atoms, estimated by the Del Re method. 14 N and 29 Si 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 (NH 2 and others) on the 29 Si 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 29 Si, 14 N and 13 C nuclei are not consistent with the fromation of intramolecular ‘long bonds’ between the solicon and nitrogen atoms in aliphatic silymethylamines.