On topological indices indicating branching. Part 2. The suitability of some physicochemical properties of alkanes as references to assess branching

The susceptibility for branching, S-i,S-j, the difference-normalised differ ence of data for octanes, Delta norm(i), as well as a number of additional criteria are used to judge the suitability of 24 physicochemical properties of alkanes as references for branching. The most appropriate as primary re ferences for branching regarding these criteria seem to be Delta Hf degrees g, Tc/Pc, and BP/Tc. They are to be used simultaneously. The following pro perties, Tc-2/Pc, omega, and C are considered less appropriate. The other t ested physicochemical properties are considered inappropriate measures of b ranching. From the data of Delta Hf degrees g, Tc/Pc, and BP/Tc, reference values for branching indices are constructed, obeying the Methane-based def inition as well as for those indices obeying the n-Alkane-based definition of molecular branching.