Kh. Kheradmand - Islamic Azad University- Arak Branch, Member of Young Researchers Club (YRC)
F. Kheradmand۲ - Chemistry Department, Faculty of Science, Islamic Azad University- Arak Branch, Arak, Iran
M. Kheradmand۳ - Physics Department, Faculty of Science, Esfahan University, Esfahan, Iran
Gh. Habibi Dehfouli۴ - Chemistry Department, Faculty of Science, Islamic Azad University- Arak Branch, Arak, Iran

The hydrocarbon compounds in petroleum have different structures. Some of them are linear and normal. This homolog series sometimes have attracted the notice for chemical and biochemical studies. The structural parameters are useful indices for examination of structure-property relationship. Graph theory is a delightful ground for the exploration of proof techniques in Discrete Mathematics and its results have applications in many areas of sciences. Topological indices are the numerical value associated with chemical constitution purporting for correlation of chemical structure with various physical properties, chemical reactivity or biological activity. In this study the quantitative structural relationship (QSR) between the number of carbon atoms in the structures of normal hydrocarbon C1 to C40, logarithm of calculated Octanol-Water partitioning coefficients and total biodegradation (logKow and TBd (mol/h), respectively), median lethal concentration 50 (LC50), water solubility (Sw, mg.L- 1/25ºC) and some of the other calculated chemical and biochemical data in the normal hydrocarbon C1 to C40 (1-40) is represented. The results would be extended for some of the other members of these compounds. The interesting results of concerning among logKow, LC50, Sw, TBd (g/h) and some of the other data with the descriptors for these compounds are presented and discussed.

Octanol-Water partitioning coefficient; Biodegradation; Molecular topology; LC50; Water solubility; Topological index; Normal hydrocarbon