QSPR Models of Boiling Points of Alkanes and Aliphatic Aldekydes, Alkanones with a Novel Connectivity Index and Its Converse Index

An atomic colouring number (fi) defined on the basis of the systematic nomenclature principle of organic compounds and the structure characteristics of bonding atoms has excellent selectivity for nonhydrogen atoms in alkanes and alkyl derivative molecules. On the basis of adjacency matrix, two novel connectivity indexes (mQ and its converse index mQ) are constructed from fi. The boiling points (Tb, K) of 85 alkanes can be expressed by means of 0Q, 1Qand δmax (the largest point valence of carbon atom): ln(714-Tb)=-0.14720Q-0.00411Q+0.0089δmax+6.5164, R=0.998 9; A satisfactory function for 72 aliphatic aldehydes and alkanones is established, i.e.: ln(693-Tb)=-0.22671Q-0.00671Q+0.0301δmax+6.1425, R=0.999 0. The boiling points for above mentioned 157 organic compounds are expressed as: ln(690-Tb)=-0.0320 0Q+ 0.00051Q+0.0195δmax+6.1590, R=0.997 6. Their correlativities are more ideal than those by the literature methods. It is concluded that the indices bear good structure selectivity and property relativity. For this new method the calculation is convenient and the result is accurate. 