title: Dibenzothiophene-platinated complexes: probing the effect of ancillary ligands on the photophysical performance.
abstract: Cyclometalation of dibenzothienyl-pyridine (HPyDBT) afforded a series of platinum(ii) complexes Pt(PyDBT)(L)Cl (L = DMSO, 1; P(p-C6H4-X)3(X = H, 2; CF3, 3; OMe, 4; NPh2, 5); 1,3,5-triaza-7-phosphaadamantane, 6; 2,6-dimethylphenyl isocyanide, 7). Chelating bidentate LL ligands formed cationic compounds [Pt(PyDBT)(LL)]+(LL = 1,2-bis(diphenylphosphino)benzene, 8; 2,2'-bipyridine, 9; 1,10-phenanthroline, 10). Oxidation of a thienyl sulfur atom allowed for the isolation of the sulfone derivative Pt(PyDBT)(PPh3)Cl (11). The title complexes were characterized crystallographically (except 7). Investigation of their photophysical behavior revealed solid state phosphorescence with quantum yields up to 0.45 for neat powders. The ancillary ligands L show a minor influence on the emission energies of the neutral compounds, but affect dramatically the intensity of luminescence. In contrast, the cationic species with diimine ligands demonstrate a significant contribution of the LL fragments into the emissive T1states that leads to a certain mixing of3IL and3LL'CT transitions and causes a substantial bathochromic shift of emission.
authors.affiliation: St.-Petersburg State University, 7/9 Universitetskaya nab., 199034 St. Petersburg, Russia.
authors.forename: Anastasia I
authors.identifier: http://orcid.org/0000-0001-7169-1978
authors.initials: AI
authors.lastname: Solomatina
authors.affiliation: University of Eastern Finland, Department of Chemistry, 80101, Joensuu, Finland. igor.koshevoy@uef.fi and Aalto University, Department of Chemistry, FI-00076 Aalto, Finland. antti.karttunen@aalto.fi.
authors.forename: Irina O
authors.initials: IO
authors.lastname: Aleksandrova
authors.affiliation: Aalto University, Department of Chemistry, FI-00076 Aalto, Finland. antti.karttunen@aalto.fi.
authors.forename: Antti J
authors.initials: AJ
authors.lastname: Karttunen
authors.affiliation: St.-Petersburg State University, 7/9 Universitetskaya nab., 199034 St. Petersburg, Russia.
authors.forename: Sergey P
authors.identifier: http://orcid.org/0000-0002-9431-0944
authors.initials: SP
authors.lastname: Tunik
authors.affiliation: University of Eastern Finland, Department of Chemistry, 80101, Joensuu, Finland. igor.koshevoy@uef.fi.
authors.forename: Igor O
authors.identifier: http://orcid.org/0000-0003-4380-1302
authors.initials: IO
authors.lastname: Koshevoy