Molecules 2005, 10(2), 334-345; doi:10.3390/10020334
Article

Valence Topological Charge-Transfer Indices for Reflecting Polarity: Correction for Heteromolecules

email
Received: 29 March 2004; Accepted: 10 May 2004 / Published: 28 February 2005
(This article belongs to the Special Issue Sulfur-Nitrogen Heterocycles)
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Abstract: Valence topological charge-transfer (CT) indices are applied to the calculationof dipole moments μ. The μ calculated by algebraic and vector semisums of the CTindices are defined. The model is generalized for molecules with heteroatoms andcorrected for sp3-heteromolecules. The ability of the indices for the description of themolecular charge distribution is established by comparing them with μ of the valence-isoelectronic series of cyclopentadiene, benzene and styrene. Two CT indices, μvec(vector semisum of vertex-pair μ) and μvecV (valence μvec) are proposed. The μvecVbehaviour is intermediate between μvec and μexperiment. The correction is produced in thecorrect direction. The best results are obtained for the greatest group. Inclusion of theheteroatom in the π-electron system is beneficial for the description of μ, owing to eitherthe role of additional p and/or d orbitals provided by the heteroatom or the role of stericfactors in the π-electron conjugation. The steric effect is almost constant along the seriesand the dominating effect is electronic. Inclusion of the heteroatom enhances μ, whichcan improve the solubility of the molecule. For heteroatoms in the same group, the ringsize and the degree of ring flattering are inversely proportional to their electronegativity.
Keywords: Charge distribution; Dipole moment; Heteroatom; Isolelectroic series; Valence topological charge-transfer index
PDF Full-text Download PDF Full-Text [151 KB, uploaded 18 June 2014 19:26 CEST]

Export to BibTeX |
EndNote


MDPI and ACS Style

Torrens, F. Valence Topological Charge-Transfer Indices for Reflecting Polarity: Correction for Heteromolecules. Molecules 2005, 10, 334-345.

AMA Style

Torrens F. Valence Topological Charge-Transfer Indices for Reflecting Polarity: Correction for Heteromolecules. Molecules. 2005; 10(2):334-345.

Chicago/Turabian Style

Torrens, F. 2005. "Valence Topological Charge-Transfer Indices for Reflecting Polarity: Correction for Heteromolecules." Molecules 10, no. 2: 334-345.

Molecules EISSN 1420-3049 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert