title: Quantum chemical characterization of the structures, thermochemical properties, and singlet-triplet splittings of didehydroquinolinium and didehydroisoquinolinium ions.
abstract: Structural and energetic properties are predicted for the 21 didehydroquinolinium ion isomers and 21 didehydroisoquinolinium ion isomers in their lowest-energy singlet and triplet states by using density functional and multireference second-order perturbation theories. Singlet-triplet splittings and biradical stabilization energies are examined to gain insight into the degree of interaction between the biradical centers, with comparison being made to analogous didehydronaphthalenes and didehydropyridines.
authors.affiliation: Department of Chemistry, Purdue University, West Lafayette, Indiana 47907, USA. jnash@purdue.edu
authors.forename: John J
authors.initials: JJ
authors.lastname: Nash
authors.forename: Hilkka I
authors.initials: HI
authors.lastname: Kenttämaa
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Cramer
mesh_terms: D005609:Free Radicals / Q000737:chemistry; D007477:Ions / Q000737:chemistry; D007546:Isoquinolines / Q000737:chemistry*; D008956:Models, Chemical; D015394:Molecular Structure; D011789:Quantum Theory; D011806:Quinolinium Compounds / Q000737:chemistry*; D013237:Stereoisomerism; D013696:Temperature
chemical_list: D005609:Free Radicals; D007477:Ions; D007546:Isoquinolines; D011806:Quinolinium Compounds