Peculiarities of NMR 1H and 13C Spectra of Alkyl Groups in Functionalized Linear Alkanes of the General Formula CH3(CH2)mY

Abstract

Literature data of NMR 1 H and 13 C spectra of linear alkanes X-(CH 2) n-Y (I), (where X = H; Y-38 different substituents, including H and CH 3) were considered. The new universal way of estimating the chemical shifts values of the methylene groups (δ H CH2 = = δ H i , δ C CH2 = δ C i , i = 1-38) in I was proposed. The concept of it considers changes in the values δ H i and δ C i of each methylene groups in I (called as increments Δδ H i and Δδ C i) as a result of conversion to I of a hypothetic alalkane-(CH 2) k-(CH 2) n-(CH 2) l-(II) by replacing infinitely long fragments-(CH 2) k-and-(CH 2) l-of it with the substituents X and Y. Increments Δδ H i and Δδ C i for all substituent types were calculated and tabulated. The proposed method allows to calculate the δ H i and δ C i parameters for the unpublished NMR 1 H and 13 C spectra of long-and medium-chain compounds I. The example of calculations was given.