Efficiently luminescent heteroleptic neutral platinum(II) complexes based on N

A series of new luminescent cycloplatinated(II) complexes (5a-8a and 5b-8b) with formulas Pt(bt)(N^O) and Pt(bt)(N^P) have been synthesized [bt = phenylbenzothiazole, N^O = (2-(1H-benzimidazole)-phenyl)diphenylphosphine oxide derivatives for 1a-4a and N^P = (2-(1H-benzimidazole)-phenyl)diphenylphosphine derivatives for 1b-4b]. The crystal structures of the complexes show distorted square planar geometries around the platinum centers. There are no obvious π-π and Pt-Pt intermolecular interactions in the crystal lattice due to the presence of sterically bulky ancillary ligands. Consequently, these complexes exhibit structured monomeric emissions in the range of 527-540 nm in CH2Cl2 solution. The photoluminescent quantum yields of Pt(bt)(N^O) (5a-8a) in CH2Cl2 solution at room temperature are higher than those of Pt(bt)(N^P) (5b-8b). The above result is well consistent with the crystal structural characteristics of the complexes. The structured emission with microsecond radiative lifetimes and the result of TD-DFT calculations indicate that the emissions of these complexes are mainly attributed to a mixed 3LC-MLCT state.

9-Phenyl-4,5-diaza-9H-fluoren-9-ol monohydrate.

The title compound, C(17)H(12)N(2)O·H(2)O, was synthesized by the reaction of 4,5-diaza-fluoren-9-one with a Grignard reagent in ether (the reaction mixture being hydrolysed with saturated NH(4)Cl solution), and crystallizes with two organic mol-ecules and two water mol-ecules in the asymmetric unit. The 4,5-diaza-fluorene fragment is approximately planar, with r.m.s. deviations of 0.0448 and 0.0198 Šin the two mol-ecules. The dihedral angles between the 4,5-diaza-fluorene planes and the phenyl ring are 80.49 (6) and 76.57 (7)°. The crystal packing features O-H⋯N and O-H⋯O hydrogen bonds involving the bridging solvent water mol-ecules, which link the mol-ecules into a three-dimensional network.

Tetra-kis[µ(3)-4-nitro-N-(5-phenyl-1,3,4-oxadiazol-2-yl)benzamidato]tetra-kis-[methano-lsodium(I)].

In the title compound, [Na(4)(C(15)H(9)N(4)O(4))(4)(CH(3)OH)(4)], the N(3)O(3) environment around the Na(+) ion is distorted octa-hedral. In the unit cell, four Na(+) ions are bridged by four Schiff base anions, leading to a tetra-nuclear complex with -4 symmetry. O-H⋯N hydrogen bonds between the methanol mol-ecule and the Schiff base anion stabilize the structural set-up.

(Acetyl-acetonato-κO,O')bis-[2-(naphth[1,2-d][1,3]oxazol-2-yl)phenyl-κC,N]iridium(III).

In the crystal structure of the title compound, [Ir(C(17)H(10)NO)(2)(C(5)H(7)O(2))], the Ir(III) atom is O,O'-chelated by the acetyl-acetonate group and C,N-chelated by the 2-aryl-naphth[1,2-d]oxazole groups. The six-coordinate metal atom displays a distorted octa-hedral geometry.

(Acetyl-acetonato-κO,O')bis-[5-meth-oxy-2-(naphth[1,2-d][1,3]oxazol-2-yl)phenyl-κC,N]iridium(III).

In the title compound, [Ir(C(18)H(12)NO(2))(2)(C(5)H(7)O(2))], the Ir atom is O,O'-chelated by the acetyl-acetonate group and C,N-chelated by the 2-aryl-naphth[1,2-d]oxazole groups. The six-coordinate metal atom displays a distorted octa-hedral geometry. Intra-molecular C-H⋯O hydrogen bonds occur. In the crystal, inter-molecular C-H⋯O hydrogen bonds link the mol-ecules into columns parallel to the b axis.