ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Binding affinities and spectra of complexes formed by dehydrotetrapyrido[20]annulene and small molecules

Z. Wang and S. Wu

Department of Chemistry, Zhejiang University, Hangzhou, 310027, P. R. China

E-mail: wushi@zju.edu.cn

Received: 18 August 2006  Revised: 3 February 2007  Accepted: 6 February 2007

Abstract: Theoretical study on the binding affinities of dehydrotetrapyrido[20] annulene to the alkene and aromatic molecules was performed using the AM1 and DFT methods. It indicated that the host possesses the ability to bind the above molecules since the binding energies of the complexes were negative. The complexes were stabilized via the hydrogen bonding, static effect, and π — π stacking interaction between the host and guest molecules. Based on the B3LYP/3-21G optimized geometries, the electronic, IR, and NMR spectra were calculated using the INDO/CIS, AM1, and B3LYP/3-21G methods, respectively. Due to the hydrogen bonding, the first absorption maxima in the electronic spectra of studied complexes were blue-shifted, whereas the main IR frequencies for some of the complexes were red-shifted. At the same time, the chemical shifts of carbon atoms forming the C=C bonds in the complexes were lower, compared to those of the host.

Keywords: macrocycles - annulenes - molecular interaction - AM1 and DFT methods

Full paper is available at www.springerlink.com.

DOI: 10.2478/s11696-007-0039-y

Chemical Papers 61 (4) 313–320 (2007)