title: The theoretical investigation of one of the derivatives of 1, 2-dithienylcyclopentene as a molecular switch.
abstract: The structural and electronic properties of a three-state molecular switch-an active device in a nano-electronic circuit-were studied using the B3LYP/6-31G* method. Due to its chemical stability, high conductivity upon doping, and non-linear optical properties, polythiophene is among the most widely studied conjugated organic polymers, both experimentally and theoretically. The aim of the present work was to theoretically study a very complex case: a three-state switch synthesized and experimentally investigated by Nishida et al. (Org Lett 6:2523-2526, 2004). An initial set of test calculations showed B3LYP level of theory and 6-31G* basis set to be the most appropriate for our purpose, i.e., the study of the structure, charge and spin distributions, as well as electrical characteristics such as electric polarizability, HOMO-LUMO gap (HLG) and electric dipole moment, for one of the 1,2-dithienylcyclopentene derivatives. Also, natural bond orbital analyses were performed to calculate local charges and charge transfers in order to study the capability of the molecule as a molecular switch. The results reported here are of general significance, and demonstrate that it is possible to use certain structural and electrical properties to understand and design electro-photochromic compounds showing a switching function in cases where stable forms can be exchanged by light or electron transfer. Figure Model of a thiophene wire incorporating a redox active unit.
authors.affiliation: Department of Physical Chemistry, Faculty of Chemistry, Iran University of Science and Technology (IUST), Narmak, Tehran, Iran. msafarpour@Iust.ac.ir
authors.forename: Mohammad Ali
authors.initials: MA
authors.lastname: Safarpour
authors.forename: Seyed Majid
authors.initials: SM
authors.lastname: Hashemianzadeh
authors.forename: Azam
authors.initials: A
authors.lastname: Kasaeian
mesh_terms: D003517:Cyclopentanes / Q000737:chemistry*; D004553:Electric Conductivity; D004583:Electrons; D007536:Isomerism; D008958:Models, Molecular; D015394:Molecular Structure; D036103:Nanotechnology / Q000379:methods*
chemical_list: C517933:1,2-dithienylcyclopentene; D003517:Cyclopentanes