An Estimation of the Thermodynamic Properties of Organic Compounds in the Ideal Gas State. I. Acyclic Compounds and Cyclic Compounds with a Ring of Cyclopentane, Cyclohexane, Benzene, or Naphthalene

Abstract

Abstract A new group-contribution method for estimating the standard enthalpy of formation, the standard absolute entropy, and the standard molar heat of organic compounds in the ideal gas state is proposed with tables of the contribution values. This method (the ABWY method) is a completely revised and enlarged version of the Anderson, Bayer, and Watson method, and it can be used with regard to a more diverse variety of compounds with a higher reliability. The neighboring effects in group-contribution methods are introduced to obtain better estimated values. The substitutions of various functional groups on aromatic rings are discriminated. Type-number corrections of the functional groups and multiple-substitution effects of halogens are also introduced; thus even heterofunctional compounds can be processed. A new concept, the quality of contribution values, is proposed to designate the qualitative reliability of the estimated physical properties. The manual procedures and tables of contribution values are given for estimating the thermodynamic properties of the compounds, as mentioned in the title, composed of C, H, O, halogens, S, and N. This method was critically compared with the Benson method in versatility and reliability.