Quantum chemical descriptors

Quantum chemical descriptors such as atomic charges, HOMO and LUMO energies, HOMO and LUMO orbital energy differences, atom-atom polarizabilities, super-delocalizabilities, molecular polarizabilities, dipole moments, and energies sucb as the beat of formation, ionization potential, electron affinity, and energy of protonation are applicable in QSAR/QSPR studies. A review is given by Karelson et al. [45]. 

CODESSA (calculation of a series of difFerent descriptors including quantum chemical descriptors) Semichem Inc. - 7204 Mullen, Shawnee, KS 66216, USA http //www.semichem.com... 

Descriptors have to be found representing the structural features which are related to the target property. This is the most important step in QSPR, and the development of powerful descriptors is of central interest in this field. Descriptors can range from simple atom- or functional group counts to quantum chemical descriptors. They can be derived on the basis of the connectivity (topological or... 

Sorich MJ, McKinnon RA, Miners JO, Winkler DA, Smith PA. Rapid prediction of chemical metabolism by human UDP-glucuronosyltransferase isoforms using quantum chemical descriptors derived with the electronegativity equalization method. J Med Chem 2004 47 5311-7. 

Karelson, M. and Lobanov, V.S. (1996). Quantum-chemical descriptors in QSAR/ QSPR studies. Chemical Reviews 96 1027-1043. 

Since experimental mechanistic investigations measure activation volumes, Rotzinger proposed to use in calculations, the currently well-accepted quantum chemical descriptor difference of sums ofr(M-O) , A Sr, for the volume of activation, AV (160). As the structures are all similar (Table I) this descriptor is in all four cases identical. 

Although one could consider the electron density as just one of the many quantum chemical descriptors available, it deserves special attention. In QSM, it is the only descriptor used for a number of reasons. The idea of using the electron density as the ultimate molecular descriptor is founded on the basic elements of quantum mechanics. First of all, it is the all-determinmg quantity in density functional theory (DFT) [11] and also holds a very close relation to the wave function. Convincing arguments were given by Handy and are attributed to Wilson [12], although initial ideas can also be traced back to Bom [13] and von... 

Basak, S. C., Mills, D., Hawkins, D. M. Predicting allergic contact dermatitis A hierarchical structure-activity relationship (SAR) approach to chemical classification using topological and quantum chemical descriptors. J. Comput. Aided Mol. Des., 2008, 22, 339-343. 

Kortvelyesi, T., Gorgenyi, M., Heberger, K. Anal. Chim. Acta 428, 2001, 73-82. Correlation between retention indices and quantum-chemical descriptors of ketones and aldehydes on stationary phases of different polarity. 

Liu W, Yi P, Tang Z (2006) QSPR Models for various proeprties of polymethacrylates based on quantum chemical descriptors. QSAR Comb Sci 25 936-943... 

Yu X, Xie Z, Yi B et al. (2007) Prediction of the thermal decomposition property of polymers using quantum chemical descriptors. Fur Polym 1 818-823... 

Semi-empirically AMl-obtained, but ad iiii/io-validated, quantum-chemical descriptors (HOMO, and... 

Descriptors derived via quantum chemistry are fundamentally different from experimentally measured quantities although there is some natural overlap. Unlike experimental measurements, quantum-chemical calculations have no statistical error. An inherent error is associated with the assumptions required to facilitate the calculations, but the computational error is considered to be approximately constant throughout the series when using quan-tum-chemistry-based descriptors with a series of related compounds. In most studies, the direction but not the magnitude of the error is known. The major weakness of quantum-chemical descriptors is the failure to directly address bulk effects of a molecule. 

Process Molecular Descriptors Physicochemical Properties Thermodynamic and Quantum Chemical Descriptors... 

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