C−H Activation by a Diplatinum(II) Complex: Isolation and Structures of [Pt₂(CH₃)(SMe₂)Ph₂(ttab)][BAr‘₄] and [Pt₂(H₂O)₂Ph₂(ttab)][BAr‘₄]₂ (ttab = 1,2,4,5-Tetrakis(1-<i>N</i>-7-azaindolyl)benzene)

The dinuclear Pt(II) complex Pt2(CH3)4(ttab) (1; ttab = 1,2,4,5-tetrakis(1-N-7-azaindolyl)benzene) has been found to activate multiple benzene molecules by cleaving a C−H bond in the presence of [H(Et2O)2][BAr‘4] (Ar‘ = 3,5-bis(trifluoromethyl)phenyl). The unprecedented dinuclear Pt(II) product [Pt2(CH3)(SMe2)Ph2(ttab)][BAr‘4] (2), which contains two phenyl groups on one Pt(II) center, has been isolated from the 1:1 reaction of 1 with [H(Et2O)2][BAr‘4]. The novel dinuclear Pt(II) complex [Pt2(H2O)2Ph2(ttab)][BAr‘4]2 (3) has been isolated from the 1:2 reaction of 1 with [H(Et2O)2][BAr‘4] when reagent-grade solvents were used in the recrystallization process. The structures of 2 and 3 have been established by X-ray diffraction analyses

New Phosphorescent Polynuclear Cu(I) Compounds Based on Linear and Star-Shaped 2-(2‘-Pyridyl)benzimidazolyl Derivatives: Syntheses, Structures, Luminescence, and Electroluminescence

Four dinuclear and trinuclear Cu(I) complexes that contain 2-(2‘-pyridyl)benzimidazolyl derivative ligands including 1,4-bis[2-(2‘-pyridyl)benzimidazolyl]benzene (1,4-bmb), 1,3-bis[2-(2‘-pyridyl)benzimidazolyl]benzene (1,3-bmb), 1,3,5-tris[2-(2‘-pyridyl)benzimidazolyl]benzene (tmb), and 4,4‘-bis[2-(2‘-pyridyl)benzimidazolyl]biphenyl (bmbp) have been synthesized. The formulas of these complexes are [Cu2(1,4-bmb)(PPh3)4][BF4]2 (1), [Cu2(1,3-bmb)(PPh3)4][BF4]2 (2), [Cu3(tmb)(PPh3)6][BF4]3 (3), and [Cu2(bmbp)(PPh3)4][BF4]2 (4), respectively. The crystal structures of 2−4 have been determined by single-crystal X-ray diffraction analyses. The Cu(I) ions in the complexes have a distorted tetrahedral geometry. For 3, two structural isomers (syn and anti) resulted from two different orientations of the three 2-(2‘-pyridyl)benzimidazolyl chelating units were observed in the crystal lattice. Variable-temperature 1H NMR experiments established the presence of syn and anti isomers for 1−3 in solution which interconvert at ambient temperature. Complexes 1−4 have a weak MLCT absorption band in the 350−450 nm region and display a yellow-orange emission when irradiated by UV light. One unexpected finding is that the yellow-orange emission of complexes 1−4 has a very long decay lifetime (∼200 μs) at 77 K. An electroluminescent (EL) device using 4 as the emitter and PVK as the host was fabricated. However, the long decay lifetime of the copper complexes may limit their applications as phosphorescent emitters in EL devices

New Phosphorescent Polynuclear Cu(I) Compounds Based on Linear and Star-Shaped 2-(2‘-Pyridyl)benzimidazolyl Derivatives: Syntheses, Structures, Luminescence, and Electroluminescence

Four dinuclear and trinuclear Cu(I) complexes that contain 2-(2‘-pyridyl)benzimidazolyl derivative ligands including 1,4-bis[2-(2‘-pyridyl)benzimidazolyl]benzene (1,4-bmb), 1,3-bis[2-(2‘-pyridyl)benzimidazolyl]benzene (1,3-bmb), 1,3,5-tris[2-(2‘-pyridyl)benzimidazolyl]benzene (tmb), and 4,4‘-bis[2-(2‘-pyridyl)benzimidazolyl]biphenyl (bmbp) have been synthesized. The formulas of these complexes are [Cu2(1,4-bmb)(PPh3)4][BF4]2 (1), [Cu2(1,3-bmb)(PPh3)4][BF4]2 (2), [Cu3(tmb)(PPh3)6][BF4]3 (3), and [Cu2(bmbp)(PPh3)4][BF4]2 (4), respectively. The crystal structures of 2−4 have been determined by single-crystal X-ray diffraction analyses. The Cu(I) ions in the complexes have a distorted tetrahedral geometry. For 3, two structural isomers (syn and anti) resulted from two different orientations of the three 2-(2‘-pyridyl)benzimidazolyl chelating units were observed in the crystal lattice. Variable-temperature 1H NMR experiments established the presence of syn and anti isomers for 1−3 in solution which interconvert at ambient temperature. Complexes 1−4 have a weak MLCT absorption band in the 350−450 nm region and display a yellow-orange emission when irradiated by UV light. One unexpected finding is that the yellow-orange emission of complexes 1−4 has a very long decay lifetime (∼200 μs) at 77 K. An electroluminescent (EL) device using 4 as the emitter and PVK as the host was fabricated. However, the long decay lifetime of the copper complexes may limit their applications as phosphorescent emitters in EL devices

New Phosphorescent Polynuclear Cu(I) Compounds Based on Linear and Star-Shaped 2-(2‘-Pyridyl)benzimidazolyl Derivatives: Syntheses, Structures, Luminescence, and Electroluminescence

Four dinuclear and trinuclear Cu(I) complexes that contain 2-(2‘-pyridyl)benzimidazolyl derivative ligands including 1,4-bis[2-(2‘-pyridyl)benzimidazolyl]benzene (1,4-bmb), 1,3-bis[2-(2‘-pyridyl)benzimidazolyl]benzene (1,3-bmb), 1,3,5-tris[2-(2‘-pyridyl)benzimidazolyl]benzene (tmb), and 4,4‘-bis[2-(2‘-pyridyl)benzimidazolyl]biphenyl (bmbp) have been synthesized. The formulas of these complexes are [Cu2(1,4-bmb)(PPh3)4][BF4]2 (1), [Cu2(1,3-bmb)(PPh3)4][BF4]2 (2), [Cu3(tmb)(PPh3)6][BF4]3 (3), and [Cu2(bmbp)(PPh3)4][BF4]2 (4), respectively. The crystal structures of 2−4 have been determined by single-crystal X-ray diffraction analyses. The Cu(I) ions in the complexes have a distorted tetrahedral geometry. For 3, two structural isomers (syn and anti) resulted from two different orientations of the three 2-(2‘-pyridyl)benzimidazolyl chelating units were observed in the crystal lattice. Variable-temperature 1H NMR experiments established the presence of syn and anti isomers for 1−3 in solution which interconvert at ambient temperature. Complexes 1−4 have a weak MLCT absorption band in the 350−450 nm region and display a yellow-orange emission when irradiated by UV light. One unexpected finding is that the yellow-orange emission of complexes 1−4 has a very long decay lifetime (∼200 μs) at 77 K. An electroluminescent (EL) device using 4 as the emitter and PVK as the host was fabricated. However, the long decay lifetime of the copper complexes may limit their applications as phosphorescent emitters in EL devices

New Phosphorescent Polynuclear Cu(I) Compounds Based on Linear and Star-Shaped 2-(2‘-Pyridyl)benzimidazolyl Derivatives: Syntheses, Structures, Luminescence, and Electroluminescence

Four dinuclear and trinuclear Cu(I) complexes that contain 2-(2‘-pyridyl)benzimidazolyl derivative ligands including 1,4-bis[2-(2‘-pyridyl)benzimidazolyl]benzene (1,4-bmb), 1,3-bis[2-(2‘-pyridyl)benzimidazolyl]benzene (1,3-bmb), 1,3,5-tris[2-(2‘-pyridyl)benzimidazolyl]benzene (tmb), and 4,4‘-bis[2-(2‘-pyridyl)benzimidazolyl]biphenyl (bmbp) have been synthesized. The formulas of these complexes are [Cu2(1,4-bmb)(PPh3)4][BF4]2 (1), [Cu2(1,3-bmb)(PPh3)4][BF4]2 (2), [Cu3(tmb)(PPh3)6][BF4]3 (3), and [Cu2(bmbp)(PPh3)4][BF4]2 (4), respectively. The crystal structures of 2−4 have been determined by single-crystal X-ray diffraction analyses. The Cu(I) ions in the complexes have a distorted tetrahedral geometry. For 3, two structural isomers (syn and anti) resulted from two different orientations of the three 2-(2‘-pyridyl)benzimidazolyl chelating units were observed in the crystal lattice. Variable-temperature 1H NMR experiments established the presence of syn and anti isomers for 1−3 in solution which interconvert at ambient temperature. Complexes 1−4 have a weak MLCT absorption band in the 350−450 nm region and display a yellow-orange emission when irradiated by UV light. One unexpected finding is that the yellow-orange emission of complexes 1−4 has a very long decay lifetime (∼200 μs) at 77 K. An electroluminescent (EL) device using 4 as the emitter and PVK as the host was fabricated. However, the long decay lifetime of the copper complexes may limit their applications as phosphorescent emitters in EL devices