Volume 29, Issue 1 pp. 69-78

Ab initio calculations on π-stacked thiophene dimer, trimer, and tetramer: Structure, interaction energy, cooperative effects, and intermolecular electronic parameters

Francisco Rodríguez-Ropero

Francisco Rodríguez-Ropero

Departament d'Enginyeria Química, E. T. S. d'Enginyeria Industrial de Barcelona, Universitat Politècnica de Catalunya, Diagonal 647, E-08028 Barcelona, Spain

Search for more papers by this author
Jordi Casanovas

Corresponding Author

Jordi Casanovas

Departament de Química, Escola Politècnica Superior, Universitat de Lleida, c/Jaume II N° 69, E-25001 Lleida, Spain

Jordi Casanovas, Departament de Química, Escola Politècnica Superior, Universitat de Lleida, c/Jaume II N° 69, E-25001 Lleida, Spain

Carlos Alemán, Departament d'Enginyeria Química, E. T. S. d'Enginyeria Industrial de Barcelona, Universitat Politècnica de Catalunya, Diagonal 647, E-08028 Barcelona, Spain

Search for more papers by this author
Carlos Alemán

Corresponding Author

Carlos Alemán

Departament d'Enginyeria Química, E. T. S. d'Enginyeria Industrial de Barcelona, Universitat Politècnica de Catalunya, Diagonal 647, E-08028 Barcelona, Spain

Jordi Casanovas, Departament de Química, Escola Politècnica Superior, Universitat de Lleida, c/Jaume II N° 69, E-25001 Lleida, Spain

Carlos Alemán, Departament d'Enginyeria Química, E. T. S. d'Enginyeria Industrial de Barcelona, Universitat Politècnica de Catalunya, Diagonal 647, E-08028 Barcelona, Spain

Search for more papers by this author
First published: 25 June 2007
Citations: 50

Abstract

π-Stacked complexes formed by two, three, and four thiophene rings have been investigated using abinitio quantum mechanical calculations. The relative orientation between the rings was investigated for each complex by exploring the corresponding potential energy surface at the MP2/6-31+G(d,p) level, the inter-ring distance, and the degree of tilting being examined in each case. Interaction energies were calculated at the MP2, MP3, MP4, and CCSD, levels of theory. Negligible or even slightly positive n-body effects have been predicted for the stacked thiophene arrangements studied in this work. This is consequence of the cancellation of favorable induction contribution by the destabilizing dispersion component. On the other hand analysis of the optimized geometries obtained for the trimer and tetramer revealed that the orientation of the rings presents a preferred degree of periodicity. Finally, we found that the lowest transition energy decreases when the size of the complex increases, this feature being attributed to desestabilization of the HOMO and stabilization of the LUMO that occur simultaneously. © 2007 Wiley Periodicals, Inc. J Comput Chem, 2008

The full text of this article hosted at iucr.org is unavailable due to technical difficulties.