Incorporation of a Fluorine Atom in a Bridging Ligand of Half-Lantern Pt II 2 Complexes Provides up to 10-Fold Enhancement of Electroluminescence Brightness.

The binuclear half-lantern platinum(II) complexes [Pt(pbt)(μ-S ∧ N)] 2 (pbtH = 2-phenylbenzothiazole, S ∧ N = benzo[ d ]thiazole-2-thiolate Pt1 , 6-fluorobenzo[ d ]thiazole-2-thiolate Pt2 , 6-chlorobenzo[ d ]thiazole-2-thiolate Pt3 , 6-bromobenzo[ d ]thiazole-2-thiolate Pt4 , and 6-iodobenzo[ d ]thiazole-2-thiolate Pt5 ) were synthesized by the treatment of the in situ formed [Pt(pbt)(NCMe) 2 ]NO 3 complex and appropriate benzo[ d ]thiazole-2-thiole in the presence of t BuOK; yield: 51-84%. Complexes Pt1 - 5 exhibit intense red photoluminescence originated from 3 MMLCT state reaching 22% room temperature quantum yields in a CH 2 Cl 2 solution. All complexes display excited-state decay kinetics both in solution and in the solid state; the kinetics was adequately modeled by single exponentials. The complexes display more than 10-fold higher electroluminescence brightness for the F-containing Pt2 (900 cd/m 2 ) and 2-fold higher electroluminescence brightness for the Cl-containing Pt3 (143 cd/m 2 ) compared to the H-substituted complex Pt1 (77 cd/m 2 ). It is argued that this impressive device luminance growth, occurred on formal replacement of H-to-F, is associated with the intermolecular strong hydrogen bonding H···F relevant to the H-bond found in the structure of Pt2 .