QSPR with TAU indices. Part-5. Liquid heat capacity of diverse functional organic compounds

Drug Theoretics and Cheminformatics Lab, Division of Medicinal and Pharmaceutical Chemistry,

Department of Pharmaceutical Technology, Jadavpur University, Kolkata-700 032, India

E-mail: kunalroy_in@yahoo.com

Department of Chemical Technology, University of Calcutta. 92, Acharya Prafulla Chandra Road. Kolkata 700 009, India
Manuscript received 31 October 2005, accepted 28 December 2005

Liquid heat capacity of a large data set (\(n\) = 871) of diverse functional compounds has been correlated with TAU indices to unravel the diagnostic feature of the TAU scheme. The data set was divided into two subsets of 436 and 435 compounds and the be~t model derived from each set was used to predict the property of compounds of the other set. II was found that the TAU relations could satisfactorily predict the variances of liquid heat capacity for both the sets (predictive r² values being 0.963 and 0.964 for sets 1 and 2 respectively).Moreover, specific contributions of functionality branching, shape and size factors to the property could be found out from the relations.In general. the liquid heat capacity increases with increase in molecular bulk and decreases with increse in branching and functionality. Furthermore. the presence of cyclicity. halogen atoms and aromaticity has negative contributions while the presence of hydrogen bond donor group has positive contribution to the liquid heat capacity. However,it appears that TAU formalism does not adequately consider the features like cyclincity, halogen atoms. aromalicity and hydrogen bonding property as indicator variables were required to improve the final relations and time there is enough scope for further development of the scheme considering these features.