Molecular Volume and Density Models for Alkanes and Monoderivatives of Hydrocarbon

Motivation. Eigenvalue of bonding orbital-connecting matrix is a good descriptor for expressing the relative bond energies of C-C and C-H bonds in alkanes. Its application can be extended to the Monoderivatives of Hydrocarbon. Method. Multivariable models were developed to predict the densities of alkanes and monosubstituted alkanes. These compounds are of special interest to petroleum or chemical engineers. Models were based on the eigenvalues of bond connecting-orbital matrix, polarizability effect index (PEI) of alkyl and Pauling’s electronegativity. The molecular volume of monosubstituted alkanes RX (X=NH2, OH, SH, F, Cl, Br, I) and alkanes can be correlated by simple linear expressions. Results. Using the model of this paper to estimate the density for RX (see Table 6), the root-mean-square error (rms), the average absolute error and the average relative error are only 0.0208 g/cm, 0.0171 g/cm and 1.85% between the experimental and estimated values respectively. Conclusions. Not only can the models of this paper give very precise calculated results but also have good predictive ability. The models can be used to predict the densities of alkanes and monosubstituted alkanes for whose densities is not measured experimentally yet, which listed in the end of this paper.