SEARCH FOR NONDEGENERATE REAL VERTEX INVARIANTS AND DERIVED TOPOLOGICAL INDEXES

Two new types of real (i.e., noninteger) local vertex invariants (LOVIs), denoted by c(i) and c(i)' and called distance-enhanced exponential connectivities, are defined via eqs. (1)-(3) and (1')-(3'), respectively. Only the case when the exponent z equals 1 in eqs. (3) and (3') is discussed in detail. Both these LOVIs span the range from 0-1, but their dependence upon topology is fairly different, as seen from Table II, where c(i) and c(i)' values for all heptane and octane isomers are displayed. From these LOVIs, by simple summation over all graph vertices two new topological indexes (TIs), denoted by XC and XC', respectively, are obtained. Their intermolecular ordering of all alkanes with four to nine carbon atoms is discussed. On their basis, correlations with boiling points and critical pressures of alkanes are presented.