title: Synthesis and spectroscopic properties of the elusive 3a,9a-diazaperylenium dication.
abstract: The 3a,9a-diazaperylenium dication (1) was synthesized for the first time in two steps from p-phenylene diamine. Ab initio calculations show a twisted ground state with a 6.4 degrees tilt between the two quinolizinium building blocks. Dication 1 is photoluminescent in fluid solutions of H(2)O, CH(3)CN, and CH(3)NO(2), but not in rigid matrices of the same solvents. This phenomenon has been attributed to a geometric relaxation of the tilted ground state into an emitting planar lowest singlet excited state. [structure: see text]
authors.affiliation: Department of Chemistry, University of Missouri-Rolla, Rolla, MO 65409, USA. leventis@umr.edu
authors.forename: Chariklia
authors.initials: C
authors.lastname: Sotiriou-Leventis
authors.forename: Abdel-Monem M
authors.initials: AM
authors.lastname: Rawashdeh
authors.forename: Woon Su
authors.initials: WS
authors.lastname: Oh
authors.forename: Nicholas
authors.initials: N
authors.lastname: Leventis
mesh_terms: D001372:Aza Compounds / Q000138:chemical synthesis*; D002413:Cations, Divalent; D007202:Indicators and Reagents; D008958:Models, Molecular; D008968:Molecular Conformation; D010569:Perylene / Q000031:analogs & derivatives* / Q000138:chemical synthesis*
chemical_list: D001372:Aza Compounds; D002413:Cations, Divalent; D007202:Indicators and Reagents; D010569:Perylene