Collect. Czech. Chem. Commun. 2008, 73, 862-872
https://doi.org/10.1135/cccc20080862

Application of Berlin's Theorem to Bond-Length Changes in Isolated Molecules and Red- and Blue-Shifting H-Bonded Clusters

Weizhou Wang and Pavel Hobza*

Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, v.v.i. and Center for Biomolecules and Complex Molecular Systems, Flemingovo nám. 2, 166 10 Prague 6, Czech Republic

Abstract

The origin of the bond-length change in molecule or molecular cluster has been investigated at the MP2/aug-cc-pVDZ level of theory using the electrostatic potential or the electron density difference analysis method. Our results have clearly shown that the bond-length change of a chemical bond is determined mainly by the balance of the electrostatic forces exerted by electrons on the two nuclei. The factors that affect the balance of the electrostatic forces include four parts: (i) The abstraction of the electron density from Berlin's binding region between the two nuclei. (ii) The accumulation of the electron density in Berlin's antibinding regions. (iii) The accumulation of the electron density in Berlin's binding region between the two nuclei. (iv) The abstraction of the electron density from Berlin's antibinding regions. Using the change of the electron density around the two nuclei of a chemical bond, we have succeeded in explaining two important chemical phenomena: (i) breakdown of bond length-bond strength correlation; (ii) the bond-length change in the hydrogen bond.

Keywords: Berlin's theorem; H-bonding; Blue-shifting H-bonding.

References: 30 live references.