title: Charge-transfer complexations of 1,n-di(9-ethylcarbazol-3-yl)alkanes with tetracyanoethylene and tetranitromethane.
abstract: 1,n-Di(9-ethylcarbazol-3-yl)alkanes, where n=1-5, as the dichromophoric model compounds of poly-3-vinylcarbazoles were synthesized to examine their complexation behaviors with the electron acceptors tetracyanoethylene (TCNE) and tetranitromethane (TNM). 9,9'-Diethyl-3,3'-dicarbazolyl, di(3-ethylcarbazol-9-yl)methane, and three monomeric analogues were also included for comparison. In dichloromethane solution, the dicarbazoles formed stable 1:1 electron donor-acceptor complexes with TCNE having formation enthalpies around -3.5kcal/mol. With TNM they formed more weakly bound complexes that showed little dependence on concentration and almost zero dependence on temperature changes having nearly 0kcal/mol enthalpies of formation. The smaller gap between the two carbazole groups in 1,n-di(9-ethylcarbazol-3-yl)alkanes with n<or=2 affected complexation adversely, while such an effect was not observed in the dicarbazoles with n>or=3.
authors.affiliation: Balikesir University, Necatibey Faculty of Education, Department of Chemistry Education, 10100 Balikesir, Turkey. asker@balikesir.edu.tr
authors.forename: Erol
authors.initials: E
authors.lastname: Asker
authors.forename: John
authors.initials: J
authors.lastname: Masnovi
mesh_terms: D000042:Absorption; D000473:Alkanes / Q000737:chemistry* / Q000378:metabolism; D002227:Carbazoles / Q000737:chemistry* / Q000378:metabolism; D004583:Electrons; D004735:Energy Transfer / Q000502:physiology; D005030:Ethylenes / Q000737:chemistry / Q000378:metabolism*; D046911:Macromolecular Substances / Q000737:chemistry / Q000378:metabolism*; D008954:Models, Biological; D008956:Models, Chemical; D009570:Nitriles / Q000737:chemistry / Q000378:metabolism*; D013774:Tetranitromethane / Q000737:chemistry / Q000378:metabolism*
chemical_list: D000473:Alkanes; D002227:Carbazoles; D005030:Ethylenes; D046911:Macromolecular Substances; D009570:Nitriles; C003393:tetracyanoethylene; D013774:Tetranitromethane