A. P. Pivovarov

New Organic Electroluminescent Materials

ABSTRACT Spectral and electric properties of five new materials for electroluminescent devices are described including materials for emitting layers and a high-Tg hole-transporting material.

A new class of electroluminescent metal complexes based on quinoline ligands containing the sulfanylamino group

The synthesis and properties of a new class of electroluminescent metal complexes based on quinoline ligands containing the sulfanylamino group in position 8 are described. These complexes contain C-N-M-N chains in the chelate cycles instead of the traditionally used C-O-M-N chains.

Electroluminescent Devices Based on Novel Zinc Complexes of Sulphonylamino Substituted Heterocycles

The electroluminescent properties of some new materials based on novel zinc complexes of sulphonylamino substituted quinolines and 2-phenylbenzazoles are reported. The electroluminescent devices based on the new complexes exhibit a bright luminosity of green or nearly white color with good luminosity efficiency up to 25–30 cd/Å.

Electronic excitation energy transfer in solid solution of 7-diethylamino-3,4-benzophenoxazine-2-one (Nile Red dye) in bis[N-2-(oxybenzylidene)-4-tert-butylaniline]zinc

Transfer of electronic excitation energy from the host material to guest molecules was studied taking the solid-phase system bis[N-(2-oxybenzylidene)-4-tert-butylaniline]zinc + 7-diethylamino-3,4-benzophenoxazine-2-one (the guest compound) as an example. The luminescence excitation spectra and the concentration quenching of green fluorescence of the host compound and the excitation of sensitized red fluorescence of the guest molecules were studied. Among the exciton mechanism of energy migration and Försters long-range, single-jump mechanism, the former dominates. The number of jumps (m) and the mean diffusion length of the singlet exciton (l), calculated in the framework of the model of partially delocalized, randomly hopping exciton, were estimated at ≈1.5·103 and ≈450 Å, respectively.

X-RAY PHOTOELECTRON SPECTRA OF POLYHYDRIDO COMPLEXES OF TUNGSTEN AND MOLYBDENUM

Abstract X-Ray photoelectron spectroscopy has been applied to study MH4L4(M = or Mo, L = PHPh2, PMePh2, PEtPh2, PBuPh2, PEt2Ph, P(OPr-i)3 or 1 2 dppe). It has been shown that tungsten in these compounds has a negative charge whereas the charge of molybdenum is almost zero.

Intramolecular hydrogen transfer from the alkyl substituent of a phosphine ligand to a metal atom upon the irradiation of tungsten phosphine hydride complexes

Conclusions1.An intramolecular hydrogen transfer from an alkyl substituent of a phosphine ligand to the metal atom was discovered upon the UV irradiation of WH4(PRPh2)4 complexes, R=CD3 and C2D5.2.The photochemical activation of methane bonds by molybdenum phosphine hydride complexes is possible in principle.

Photochemical interaction of phosphine hydride complexes of molybdenum and tungsten with benzene and cyclohexane

Conclusions1.Upon irradiation of phosphine hydride complexes of molybdenum and tungsten in benzene or cyclohexane, the products from photochemical dehydrogenation of the complexes are capable of abstracting hydrogen from the solvents, the molybdenum compounds being more reactive than the analogous tungsten complexes.2.A decrease in the irradiation wavelength increases the efficiency of interaction of MH4L4 with the solvents.3.Complexes with monodentate ligands are more reactive than complexes containing bidentate ligands.

Determination of charge-transfer electron transitions in tungsten tetrahydride complexes stabilized by organophosphorus ligands by X-ray photoelectron and UV absorption spectra

A change in the energy of the long-wave transition in the UV absorption spectra of tetrahydride complexes WH4L4 is equal to the change in the energy of the internal 2p-level of phosphorus. Based on the correlation determined, the electron transitions related to the long-wave absorption bands in the UV spectra were assigned to the charge-transfer transitions from the organophosphorus ligand to tungsten.

PHOTOCHEMICAL INTERACTION OF MOLYBDENUM AND TUNGSTEN PHOSPHINE HYDRIDE COMPLEXES WITH CARBON DIOXIDE

UV, IR, and1H NMR spectra of photoproducts obtained by irradiation of phosphine hydride complexes MH4L4 (M = Mo and W; L = PHPh2, PMePh2, PEtPh2, PEt2Ph, and PBuPh2) in an atmosphere of CO2,13CO2, and C18O2 have been studied. The photoproducts can be formed due to the insertion of carbon dioxide both into the M-H bond and M-C and M-Ph bonds.

Photochemical reduction of carbon dioxide to formate in the coordination sphere of MoH4(PH2PCH2CH2PPh2)2

UV, IR, and NMR spectra of photolysis products obtained by irradiation of MoH4(Ph2PCH2CH2PPh2)2 (1) in an atmosphere of CO2,13CO2, or C18O2 were studied. In the coordination sphere of1, photochemical reduction of carbon dioxide occurs, yielding products of formate type. Treatment of photoproducts with acids affords formaldehyde.