The influence of the second methyl group position on the chemical shifts values of all protons in dimethylalkane molecules in the 1H NMR spectra.

Abstract

The protons chemical shifts values in the PMR spectra of dimethylalkanes of general formula N 1 ,N 2 -n (when n is the letter designation of linear alkane, and N 1 , N 2 are the carbon atom numbers which are attached to the methyl groups in the alkyl chain of n) have analyzed. It is calculated and discussed the individual (N 1 ,N 2 -n-i), the arithmetic means (N 1 ,N 2 -n-i) "standard" differential parameters (the difference between absorption of studied proton in N 1 ,N 2 -n and its absorption in the n) and the "integral spectral changes" Σ N 1 ,N 2 -n-i that occur in process n → N 1 ,N 2 -n). Also it is calculated and discussed the individual (N 1 ,N 2 -n'-i) and the arithmetic means (N 1 ,N 2 -n'-i) additional differential parameters (the difference between absorption of studied proton in N 1 ,N 2 -n and its absorption in the correspondent monomethylalkane Nn) of dimethylalkanes N 1 ,N 2 -n.