The correlation between molecular structure parameters of O-ethyl N-isopropyl phosphoro(thioureido)thioates and their retention data in RP-HPLC

A retention prediction system(RPS)of seven O-ethyl N-isopropyl phosphoro(thioureido)- thioates in reversed phase HPLC was investigated.The system is based on the solvent selectivity triangle concept.Three molecular structure parameters(hydrophobicity Ⅱ,substituent length L, and substituent maximum width B_5)were used to describe the quantitative structure-retention relation- ships.With these quantitative relationships,the retention behaviours of other eight homologs for different mobile phase composition were predicted.The predicted values were consistent with the measured values within relative error of 10%,which means that it is possible to apply the reported method to predict retention values for qualitative purposes for different mobile phase compositions.

Extracting Structure Parameters of Dimers for Molecular Tunneling Ionization Model

We determine structure parameters of the highest occupied molecular orbital(HOMO)of 27 dimers for the molecular tunneling ionization(so called MO-ADK)model of Tong et al.[Phys.Rev.A 66(2002)033402].The molecular wave functions with correct asymptotic behavior are obtained by solving the time-independent Schr(o|¨)dinger equation with B-spline functions and molecular potentials which are numerically created using the density functional theory.We examine the alignment-dependent tunneling ionization probabilities from MO-ADK model for several molecules by comparing with the molecular strong-field approximation(MO-SFA)calculations.We show the molecular PerelomovPopov-Terent'ev(MO-PPT)can successfully give the laser wavelength dependence of ionization rates(or probabilities).Based on the MO-PPT model,two diatomic molecules having valence orbital with antibonding systems(i.e.,Cl_2,Ne_2)show strong ionization suppression when compared with their corresponding closest companion atoms.

Accurate Structure Parameters for Tunneling Ionization Rates of Gas-Phase Linear Molecules

In the molecular Ammosov–Delone–Krainov(MO-ADK) model of Tong et al. [Phys. Rev. A 66(2002)033402], the ionization rate depends on the structure parameters of the molecular orbital from which the electron is removed. We determine systematically and tabulate accurate structure parameters of the highest occupied molecular orbital(HOMO) for 123 gas-phase linear molecules by solving time-independent Schr¨odinger equation with B-spline functions and molecular potentials which are constructed numerically using the modified Leeuwen–Baerends(LBα)model.

Investigation of Angular Dependence of Strong-Field Tunneling Ionization for Asymmetric Diatomic Molecule HeH^(2+)

We determine the structure parameters for the asymmetric heteronuclear diatomic molecule HeH2＋ at several internuclear distances with the molecular wavefunctions obtained by solving the time-independent Schr6dinger equation with B-spline basis. Then the angular dependence of strong-field ionization rates of HeH2＋ are investigated with the molecular tunneling ionization theory. We show that the shape of several lowly excited states （i.e. 2pσ, 2pπ, 3dσ） for HeH2＋ are reflected in the orientation dependent ionization rates very well, however, the angle-dependent ionization rate fails to follow the angular distribution of the asymptotic electron density for the ground state lsσ. We also show that the internuclear distance dependent ionization probabilities are in a good agreement with the more accurate result obtained from the numerical solution of the time-dependent Schr6dinger equation.