Predicting the Kovats retention index for alkoxyl silicon chlorides and sulfides ion stationary phases of different polarities using novel definition of molecular topological index

The valence delta delta(i)(y) based on the structural characteristic bonding atom i and mirror its chemical surroundings of molecular was defined: delta(i)(y) = [m(i)(Z(i)-h(i)) + Sigma (LiLj)]/[n(i)(2)(L-i + 1)] Based on the adjacency index, a novel molecular structure information connectivity index Y-m was proposed: Y-m= SigmaPi(delta(i)(y))(0.5)(j). the molecular structure information connectivity indices of 22 alkoxyl silicon chlorides 61 sulfides and 74 alkanes were calculated. Y-0 and Y-1 were ease to be calculated and have good discrimination between isomeric organic compounds. Quantitative structure-etention relationships (QSRR) on gas chromatography retention index (RI) of 22 alkoxyl silicon chlorides, 61sulfides were. proposed respectively by multiple linear regression method with good stability and predictability. It has been demonstrated that the method possesses the advantage of easy computation and clear physical significance. The estimated results with above QSRR models are all better than the relevant achievements of literatures. All these results show that the connectivity index Y-m of edge valence is an important parameter in QSRR studies.