Heteroorganic derivatives of furan. 65. Effect of substituents on shielding of 1H, 13C,and 29Si and 29Si-13C spin-spin coupling constants in NMR spectra of 2-substituted furans and 5-trimethylsilylfurans

The results of an investigation of 2-substituted furans and 5-trimethylsilylfurans by NMR spectroscopy and the CNDO/2 method showed that the chemical shifts of the different nuclei do not correlate sufficiently clearly with the calculated charges because of an additional change in the electron density under the influence of a -d interaction. The ¹³C-²⁹Si direct spin-spin coupling constants (SSCC) are less sensitive to this interaction, since they depend primarily on the inductive effects of the substituents.See [1] for Communication 64.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 588–596, May, 1990.