Relationship between the electron density and the topology of carbon atoms in acyclic alkanes

A comparison of the results of the calculation of the electron density on carbon atoms in saturated acyclic C1-C8 hydrocarbons obtained by the MINDO/2, MINDO/3, and CNDO/BW methods has shown that these results convey the relationship between the magnitude of the charge on each carbon atom and its topology and correlate with the experimental values of the chemical shifts delta(C-13) in the NMR spectrum. A mathematical expression, which relates the electron density to the structural topology of the carbon atoms in the molecules of saturated acyclic hydrocarbons and makes it possible to perform calculations for large molecules having different isomeric structures with a good degree of accuracy, has been proposed.