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Two coumarin derivatives containing electron-transporting benzoxazolyl moiety, 7-(diethylamino)-3-(benzoxazol-2-yl)coumarin (DABOC) and 3-(benzoxazol-2-yl)benzo[5,6]coumarin (BOBC), were synthesized and characterized. The photoluminescence and electroluminescence of the compounds were investigated detailedly. The compounds exhibited strong blue-green emissions in both solution and solid states, but the devices with DABOC as the emitting layer exhibited orange emission and maximum luminous efficiency of 2.8 cd/A and maximum luminance of 8,800 cd/m(2), and the devices with BOBC displayed orange-white emission and maximum luminous efficiency of 0.13 cd/A and maximum luminance of 540 cd/m(2).

A new coumarin derivative, 3-(4-(anthracen-10-yl)phenyl)-benzo[5,6]coumarin, was synthesized and characterized by FT-IR, (1)H NMR, element analysis and single crystal X-ray crystallography. The dihedral angle of benzo[5,6]coumarin ring and phenyl group is 36.15 degrees, and the dihedral angle of phenyl group and anthracene skeleton is 89.37 degrees. The UV-vis absorption and photoluminescence of the compound were discussed. The result shown that the compound exhibits high fluorescence quantum yield (Phi(F)), large Stokes shift and green emission (508 nm). The molecular structure of the compound was optimized using density functional theory (DFT) at B3LYP/6-31G(d) level, and the HOMO and LUMO levels of the compound were deduced.

Two novel tripodal compounds, tris[2-(7-diethylamino-coumarin-3-carboxamide)ethyl]amine (Tren-C1) and tris[2-(benzo[5,6]coumarin-3-carboxamide)ethyl]amine (Tren-C2), were synthesized and characterized. The UV-vis and fluorescence properties of Tren-C1 and Tren-C2 in solutions were investigated. These two compounds exhibited strong blue emission under ultraviolet light excitation. The maximal fluorescence emission occurred at about the level of 10(-5) mol/L. The chromophore units in the tripodal compounds shown a little interaction in the ground state, while the interactions in the excited state was notable and which leads to a broad and bathochromic shift of the emission bands.

A novel 3-(1H-4-methyl-benzotriazol-1-yl)-4-methyl-benzo[7,8]coumarin(MBMBC) containing an electron-transporting moiety (benzotriazole) was characterized single crystal X-ray crystallography and UV-vis absorption spectra. The compound exhibits strong blue emission and may prove to be important class of OLED material.

A new complex, ZnL, was synthesized and characterized by spectral data (infrared, UV-vis, fluorescence), in which the ligand compound is N1,N2-bis (pyridine-2-ylonethylene) benzene-1,2-diamine (L). ZnL exhibits a strong emission peak at 414 nm.

Triethylene-glycol di (7-(N, N'-diethylamino))-coumarin-3-carboxylate was synthesized and the photoluminescent behavior was discussed. This compound exhibits a strong blue emission peak at 464 nm and has potential possible to explore organic electroluminescent materials.

A ternary gallium complex with mixed ligands were synthesized. The photoluminescence and electroluminescence of the complex were investigated. The device exhibited bright green emission and the maximum brightness of 3800 cd/m2 was achieved.

The structure of 7-(N,N'-diethylamino)-coumarin-3-carboxylic acid (DCCA) was verified by single crystal X-ray crystallography. The UV-vis absorption and fluorescence of DCCA were discussed. The compound exhibits strong blue emission under ultraviolet light excitation. The molecular structure of DCCA was optimized using density function theory (DFT) at B3LYP/6-31G level, showing that the optimized geometers parameters are in good agreement with experiment data. In addition, the HOMO and LUMO levels of DCCA were deduced.

Two new iridium organometallic compounds based on acetylacetone derivative ligands containing carrier-transporting groups, Ir(L)2(acac-Ox) and Ir(L)2(acac-Cz), where L = 3-(pyridin-2-yl)coumarinato N, C4, acac-Ox = 3-(4-(5-(4′-tert-butylphenyl)-1,3,4-oxadiazole)benzyl)-pentane-2,4-dionate and acac-Cz = 3-((4-(9H-carbazol-9-yl)phenyl)methyl)pentane-2,4-dionate, have been successfully synthesized and characterized by elemental analysis, 1H NMR and FT-IR. The structure of the free ligand acac-Ox was established by single-crystal X-ray analysis as a cis-configurational enol of β-diketone. The photophysical properties of the complexes were examined by using UV-vis, photoluminescence spectroscopic analysis. The doped light-emitting devices with a configuration of ITO/MoO3 (2 nm)/NPB (35 nm)/TCTA (5 nm)/CBP:Ir(III) complex (x wt %, 20 nm)/TPBi (40 nm)/LiF (1 nm)/Al (150 nm) were fabricated. The devices based on Ir(L)2(acac-Cz) with a 9 wt% doping concentration showed the best EL efficiency performance, and exhibited green emission with a maximum external quantum efficiency (EQE) of 7.77% and a maximum luminous efficiency of 28.2 cd A−1 at a current density of 2.27 mA cm−2, and a maximum luminance of 6348.7 cd m−2 at 11 V. When the doping concentration is 6 wt%, a maximum brightness of 4230 cd m−2 at 16 V and a maximum current efficiency of 20.33 at 1.23 mA cm−2 and a maximum external quantum efficiency (EQE) of 5.54% were achieved in the devices based on Ir(L)2(acac-Ox). By comparison of the electroluminescent performances of the devices based on Ir(L)2(acac-Ox) and Ir(L)2(acac-Cz), it was shown that the introduction of the hole-transporting group into the ligand improves the performance of Ir(L)2(acac-Cz) doped devices.

The crystal structure of [Cu(PMBP)(PPh3)2]BF4·CH2Cl2 (PMBP = 1-phenyl-3-methyl-4-benzoyl-pyrazolon-5-ato) was determined by X-ray crystallography. The complex crystallized in the triclinic system, space group P1, with a = 9.6864(6), b = 13.6845(9), c = 20.0329(13)A, α = 102.119(1), β = 94.865(1), γ = 105.120(1)°, Z = 2, V = 2478.8(3)A3, and R = 0.0498. The Cu(II) ion is coordinated by two O donor atoms from PMBP and two P atoms from triphenylphosphine molecules to form a distorted tetrahedral geometry.

The crystal structure of Ir(1-piq)2(pic-3-OH) (1-piq = 1-phenylisoquinoline, pic-3-OH = 3-hydroxypicolinate) was determined by X-ray crystallography. The complex crystallized in the triclinic system, space group P1, with a = 10.6477(7)A, b = 11.9891(8)A, c = 14.7693(9)A, α = 94.758(1)°, β = 105.936(10)°, γ = 114.140(1)°, Z = 2, V = 1612.92(18)A3, and R = 0.0305. The crystal structure consists of a distorted octahedral geometry around the iridium.

The molecule of the title compound, C31H29N3, contains a hexyl chain, a coordination unit (benzimidazole) and a functional group (carbazole). The benzimidazole ring is not coplanar with either the phenyl ring or the carbazole system, making dihedral angles of 43.26 (3) and 39.03 (2)°, respectively. The dihedral angle between the phenyl ring and the carbazole system is 24.42 (3)°. The hexyl Cβ atom (with respect to benzimidazole) deviates by 1.124 (2) Å from the benzimidazole plane, although the Cα atom lies in the plane. The hexyl Cβ atom (with respect to carbazole) deviates by 1.315 (1) Å from the carbazole plane, although the Cα atom lies in the plane. The crystal structure is stabilized by intermolecular C—H...π interactions.

A novel tripodal compound, tris[2-(7-diethylamino-coumarin-3-carboxamide)ethyl]amine (Tren-C), was synthesized and characterized by elemental analysis, infrared and 1H-NMR spectra. The photoluminescent (PL) and electroluminescent properties of Tren-C were investigated. Tren-C exhibits different colour emissions in solid states and solutions. The electroluminescence devices comprising vacuum vapour-deposited films using the compound as a dopant were fabricated, showing blue emissions that are identical to its PL spectrum in chloroform solutions. With the device structure of indium tin oxide (ITO)/4, 4', 4''-tris-N-naphthyl-N-phenylamino-triphenylamine (2-TNATA) (5 nm)/N, N'-bis-(naphthyl)-N, N'-diphenyl-1, 1'-biphenyl-4, 4'-diamine (NPB) (40 nm)/4, 4'-bis(9-carbazolyl) biphenyl (CBP) : Tren-C (0.5 wt%, 30 nm)/2-(4-biphenylyl)-5-(4-tert-butylphenyl)-1, 3, 4-oxadiazole (Bu-PBD) (30 nm)/LiF (1 nm)/Al (100 nm), a maximum external quantum efficiency of 2.85%, a maximum luminous efficiency of 3.85 cd A−1 and a maximum luminance of 1450 cd m−2 are realized.