Ruslan Petrukhin

Correlation of the Melting Points of Potential Ionic Liquids (Imidazolium Bromides and Benzimidazolium Bromides) Using the CODESSA Program

The melting points of several imidazolium-based ionic liquids or ionic liquid analogues were correlated using the CODESSA program in order to develop predictive tools for determination of suitable ionic liquid salts. The data set consisted of melting point data (degrees C) for 104 substituted imidazolium bromides divided on the basis of the N-substituents into three subsets: A-57 compounds, B-29 compounds, and C-18 compounds. The 45 benzimidazolium bromides form set D. Five-parameter correlations were obtained for (i) set A with R2 = 0.7442, (ii) set B with R2 = 0.7517, and (iii) set D with R2 = 0.6899, while set C was correlated with a three parameter equation with R(2) = 0.9432. These descriptors for predicting the melting points of the imidazolium and benzimidazolium bromides were based on the size and electrostatic interactions in the cations.

QSPR correlation of the melting point for pyridinium bromides, potential ionic liquids.

In an attempt to develop predictive tools for the determination of new ionic liquid solvents, QSPR models for the melting points of 126 structurally diverse pyridinium bromides in the temperature range 30-200 degrees C were developed with the CODESSA program. Six- and two-descriptor equations with squared correlation coefficients (R(2)) of 0.788 and 0.713, respectively, are reported for the melting temperatures. The models illustrate the importance of information content indices, total entropy, and the average nucleophilic reactivity index for an N atom.

QSPR Analysis of Flash Points

A quantitative structure property relationship study of the flash point of a diverse set of 271 compounds provided a general three-parameter QSPR model (R(2) = 0.9020, R(2)(cv) = 0.8985, s = 16.1). Use of the experimental boiling point as a descriptor gives a three-descriptor equation with R(2) = 0.9529. Use of the boiling point predicted by a four-parameter reported relationship gives a three-parameter flash point equation with a R(2) value of 0.9247.

The Present Utility and Future Potential for Medicinal Chemistry of QSAR / QSPR with Whole Molecule Descriptors

Whole-molecule descriptors are obtained computationally from molecular structures using a variety of programs. Their applications are reviewed in the areas of solubility, bioavailability, bio- and nonbio-degradability and toxicity.

CODESSA-Based Theoretical QSPR Model for Hydantoin HPLC-RT Lipophilicities

A quantitative structure property relationship investigation was performed on the lipophilicities of a number of hydantoin derivatives as measured by the RP-HPLC retention times provided by Scholl et al. (Scholl, S.; Koch, A.; Henning, D.; Kempter, G.; Kleinpeter, E. Struct. Chem. 1999, 10, 355-366). The lipophilicities (S) were correlated with the theoretical molecular descriptors of the hydantoins obtained using the CODESSA program from the AM1-optimized geometry and electron wave functions. This study discloses enhanced correlations of the lipophilicities with the molecular descriptors, wherein the influence of the entropy factor is found to predominate.

Prediction of ultraviolet spectral absorbance using quantitative structure-property relationships.

High performance liquid chromatography (HPLC) with ultraviolet (UV) spectrophotometric detection is a common method for analyzing reaction products in organic chemistry. This procedure would benefit from a computational model for predicting the relative response of organic molecules. Models are now reported for the prediction of the integrated UV absorbance for a diverse set of organic compounds using a quantitative structure-property relationship (QSPR) approach. A seven-descriptor linear correlation with a squared correlation coefficient (R2) of 0.815 is reported for a data set of 521 compounds. Using the sum of ZINDO oscillator strengths in the integration range as an additional descriptor allowed reduction in the number of descriptors producing a robust model for 460 compounds with five descriptors and a squared correlation coefficient 0.857. The descriptors used in the models are discussed with respect to the physical nature of the UV absorption process.

QSRR Correlation of Free-Radical Polymerization Chain-Transfer Constants for Styrene

Quantitative structure-reactivity relationships (QSRR) are deduced for kinetic chain-transfer constants for 90 agents on styrene polymerization at 60 degrees C. Three- and five-parameter correlations were obtained with R2 of 0.725 and 0.818, respectively. The descriptors involved in the correlations are consistent with the proposed mechanism of the chain-transfer reactions.

QSAR Correlations of the Algistatic Activity of 5-Amino-1-Aryl-1H-Tetrazoles

Abstract The algistatic activity of 20 substituted 5-aminol-aryl-1H-tetrazoles was correlated with the second order Kier and Hall index, the XY shadow on the XY rectangle and the total hybridization component of the molecular dipole by the CODESSA program in a three parameter equation with r2 = 0.9330.

The chemical inventory system of the center for heterocyclic compounds, University of Florida.

A system suitable for tracking the amounts and locations of ca. 10 000 chemicals is described.