Dinuclear copper(I) complexes with substituted benzimidazole ligands. Synthesis and photo- and electroluminescent properties

New dinuclear copper(I) complexes with bridging bis-diimine ligands were synthesized on the basis of benzimidazole derivatives. The obtained complexes showed photo- and electroluminescent properties. Copper-containing emitters exhibited yellow, orange, and yellow–green electroluminescence with a maximum brightness of 1166 cd/m².     

Synthesis,structures, and properties of a family of 3d-based MOFs constructed from mixed ligands

Transition Metal Chemistry - By the use of co-ligands tri(2-carboxyethyl)-isocyanurate) (H3tci) and 1H-3-(3-pyridyl)-5-(4-pyridyl)-1,2,4-triazole (3,4′-bpt), three coordination complexes,...     

Synthesis, crystal structure, and luminescent properties of a binuclear gallium complex with mixed ligands

By introducing tridentate Schiff base ligands, a binuclear gallium complex with mixed ligands, bis(salicylidene-o-aminophenolato)-bis(8-quinolinolato)-bis-gallium(III) [Ga(2)(saph)(2)q(2)], has been synthesized and structurally characterized by single-crystal X-ray crystallography. Crystal data for C(44)H(30)Ga(2)N(4)O(6) are as follows: space group, triclinic, P; a = 11.357(3) A, b = 12.945(3) A, c = 12.947(3) A, alpha = 103.461(15) degrees, beta = 100.070(7) degrees, gamma = 96.107(18) degrees, Z = 2. This complex was identified as a dimeric complex of hexacoordinated gallium with strong intermolecular and intramolecular pi-pi stacking interactions between the pyridyl/pyridyl rings. The thermal analysis showed that Ga(2)(saph)(2)q(2) can readily form a stable amorphous glass with a high glass transition temperature (T(g) = 204 degrees C), which is 27 degrees C higher than that of tris(8-hydroxyquinolinolate)aluminum (Alq(3)). In addition, a high photoluminescence efficiency (phi(PL)) of 0.318 in DMF has been demonstrated, although the central gallium atom can result in heavy-atom quenching. Organic light-emitting diodes (OLEDs) based on this complex displayed a turn-on voltage as low as 2.5 V and a high efficiency. Even at a low doping concentration of 1%, the doped Ga(2)(saph)(2)q(2) devices with 4-(dicyanomethylene)-2-tert-butyl-6-(1,1,7,7-tetramethyljulolidyl-9-enyl)-4H-pyran (DCJTB) as the dopant exhibited excellent red emission centered at 628 nm with improved durability, compared with the case of Alq(3) as the host. These distinguishing properties of Ga(2)(saph)(2)q(2) make it a good candidate as a novel electron-transporting and emitting material for OLEDs.     

Synthesis and properties of substituted 2-thioxohexahydropyrimidine-5-carbohydrazides

A regioselective method for the synthesis of substituted (4R*,5S*,6R*)-2-thioxohexahydro-pyrimidine-5-carbohydrazides from the corresponding diastereomers of hexahydro-2H-chromeno[4,3-d]pyrimidines was developed. In acidic medium, the obtained hydrazides are prone to retro reaction to give hexahydro-2H-chromeno[4,3-d]pyrimidines.

     

Synthesis and fluorescent properties of novel chiral 1,2-diaminocyclohexane substituted ligands and their complexes

A series of novel chiral 1,2-diaminocyclohexane derivatives bearing heterocyclic units were synthesized via improved methods under ultrasonic irradiation. The photophysical properties of compounds were studied in ethanol, methanol, and chloroform. The sensitivity of these amines toward Cu²⁺, Cd²⁺, and Ni²⁺ was studied by the UV–vis and fluorescent methods. The π-electron structure of thiophene and bithiophene containing sensors is the most active toward all above mentioned metal ions and is highly selective for Ni²⁺ and Cd²⁺.     

Synthesis and performance of ansa-metallocene catalysts with substituted heterocyclic and indenyl ligands

Synthesis of new ansa-metallocene catalysts incorporating branched alkyl groups alpha to the bridgehead carbon of indenyl and thiapentalenyl ligands is reported. Me₂Si(2-Me-4-Ph-Indenyl)₂ZrCl₂ and Me₂Si(2,5-Me₂-3-Ph-Thiapentalenyl)₂ZrCl₂ type metallocenes with one and two isopropyl groups substituted for 2-methyl substitutents were prepared and used as procatalysts in propylene polymerizations and E/P copolymerizations. The 2-isopropyl groups influenced catalyst activity, molecular weight, and the relative amounts of microstructure errors. In contrast to procatalysts with only 2-methyl groups, polymer molecular weights increased in E/P copolymerizations with 2-isopropyl substituted complexes. The text was submitted by the authors in English.     

Synthesis and properties of a mixed thiophene-octahomotetraoxacalixarene

The synthesis of a mixed thiophene unit containing octahomotetraoxa[2]thiophenecalix[2]arene is described. Its single-crystal X-ray structure and a preliminary solution complexation study are reported herein.     

Synthesis,crystal structure and electrochemical properties of carbonylchromium and tungsten complexes containing substituted pyrazole ligands

A series of carbonylchromium and tungsten complexes containing substituted pyrazole ligands, M(CO)₅L, have been synthesized by the photochemical reactions of substituted pyrazoles with M(CO)₆ (M = Cr or W). Their electrochemical behavior, investigated by cyclic voltammetry, indicates that the chromium complexes exhibit one reversible or quasi-reversible couple corresponding to a one-electron oxidation, whereas the tungsten complexes have one irreversible oxidation process. The crystal structure of W(CO)₅L [L = 3(5)-t-butylpyrazole] was determined by X-ray diffraction, indicating that 3(5)-t-butylpyrazole is a monodentate ligand, and that the central metal is six-coordinate with a quasi-octahedral coordination geometry. All new compounds were characterized by elemental analyses, i.r., ¹H-n.m.r. and by ¹³C-n.m.r. in the case of the tungsten complexes.     

Synthesis,structure and catalytic properties of new half-titanocene complexes bearing substituted cyclopentadienyl and aryloxide ligands

New cyclopentadienyltitanium aryloxide complexes, 1-phenyl-2,3,4,5-Me4CpTi(O-2,6-ⁱPr₂-4-ⁿBu-C₆H₂)Cl₂ (1) and [4,4′-biphenyl-(2,3,4,5-Me₄Cp)₂][Ti(O-2,6-ⁱPr₂-4-ⁿBu-C₆H₂)Cl₂]₂ (2), have been prepared by treatment of cyclopentadienyltitanium trichloride complexes [PhMe₄CpTiCl₃ and 4,4′-biphenyl-(Me₄CpTiCl₃)₂] with 1 or 2 equiv of lithium salt of 2,6-di-isopropyl-4-butylphenol. Complexes 1 and 2 have been characterized by elemental analysis, ¹H and ¹³C NMR spectroscopy. The molecular structure of 1 has been determined by single-crystal X-ray diffraction. Upon activation with ⁱBu₃Al and Ph₃CB(C₆F₅)₄, 1 and 2 both exhibit good catalytic activity for ethylene polymerization, producing polyethylene with moderate molecular weight and melting point.     

Synthesis of 2,5′-bipyrimidines from substituted 5-cyanopyrimidines

The Pinner method was applied to substituted 5-cyanopyrimidines to obtain 5-aminopyrimidines, which were condensed with acrolein derivatives to synthesize compounds that contain a 2,5-bipyrimidine fragment.Deceased.Translated from Khimiya Geterotsiklicheskikh Soedinenii, Vol. 24, No. 3 pp. 371–375, March, 1988.     

Synthesis and thermotropic liquid-crystalline properties of N-alkylpyridinium bromides substituted with a terphenylene moiety

Molecules containing a terphenylene core, two alkyl chains and a pyridinium ring associated with its bromine counterion were synthesised and their liquid crystalline properties were studied by differential scanning calorimetry, polarising optical microscopy and X-ray diffraction. The results were compared with those of chemical intermediates, which also develop a liquid crystalline behaviour. Both intermediates and pyridinium salts showed a rich polymorphism at temperatures ranging from around 100 to 200°C and 115 to 220°C, respectively. X-ray results indicate that both intermediates and pyridinium salts develop tilted smectic mesophases with molecules stacked in single and double layers, respectively. The tilt angle of some of these compounds decreases so markedly upon cooling that molecules attain almost an orthogonal position. The stacking of molecules in the smectic layers was explained in terms of the mutual repulsion interactions between the terphenylene core, the alkyl chains and the ionic species (the pyridinium ring associated with its counterion) and it was proposed that the π–π interactions between the long aromatic cores counterbalance the strong forces between the ionic species, leading to a full segregation of these molecular parts in periodic sublayers. A molecular arrangement model is proposed for these salts.     

Synthesis and properties of substituted benzaldehyde phenylhydrazones

Phenylhydrazones containing hydroxy, alkoxy and acyloxy groups are synthesized from aromatic aldehydes of vanillin series by reaction with phenylhydrazine.     

Synthesis and properties of substituted 2-imidazolidinones

4-Hydroxy- and 4-hydroxylamino-1-hydroxy-3-aryl-5,5-dimethyl-2-imidazolidinones, respectively, were obtained by treatment of N-arylcarbamoyl derivatives of N-(1-oximino-2-methyl-2-porpyl)hydroxylamine with acids and alkalis. 4-Hydroxylaminoimidazolidinones react with p-nitrobenzaldehyde to give nitrones and are converted in acidic media to 4-hydroxy derivatives, which by the action of methanol in the presence of p-toluenesulfonic acid give 4-methoxy-2-imidazolidinones. Acylation and alkylation of 4-hydroxy- and 4-methoxy-2-imidazolidinones take place at the hydroxy group attached to N(₁).Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1255–1261, September, 1976.     

Synthesis and physical properties of laterally fluoro substituted ferroelectric liquid crystals with a fluoro substituted chiral terminal chain

A new series of ferroelectric liquid crystals (FLCs) has been designed for active matrix displays based upon the chiral smectic C phase. The FLCs have been derived from optically active fluorinated alkanols and a laterally fluoro substituted biphenylyl-1,3-dioxan core. Their physical properties such as spontaneous polarization, current response time, and tilt angle have been determined. The FLC derived from 2-fluoro-octanol showed a very short current response time of 10μs at T _Sm*-N* - T= 10°C, while another FLC with the same core derived from 5-fluoro-octanol gave a value of 150μs.     

Synthesis of functionally substituted 5-phenylthiazoles

The reaction of esters and amides of 3-phenyl-3-chloro-2-oxopropionic acid with thioamides and thiourea gave new 5-phenylthiazoles.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 12, pp. 2854–2856. December, 1990.     

Synthesis, crystal structure and magnetic properties of an enneanuclear manganese cluster containing mixed chelating ligands

A new mixed-valence [Mn₉] cluster of formulae [Mn₉O(OH)₃Cl₄(N₃)₃(hmp)₆(dpkd)₃]·1.5CH₃CN·3H₂O (1·1.5CH₃CN·3H₂O, where hmp⁻ and dpkd²⁻ are the anion of 2-hydroxymethylpyridine and the dianion of the gem-diol form of the dpk, respectively) has been synthesized and characterized by single-crystal X-ray diffraction, IR spectra, elemental analysis and magnetic measurements. Single-crystal structural analysis shows that complex 1 contains a [Mn₉] core with a new structural topology in the Mn clusters, in which the centered six Mn^III atoms compose a trigonal antiprism and the peripheral residual three Mn^II atoms can be seen as the skirt hem of this antiprism. DC magnetic susceptibility studies indicate that the overall antiferromagnetic interactions between Mn ions are present in the cluster. Fitting the data of magnetization and extrapolation of the χ_M′T suggest the spin ground states of S = 3.5, and no out-of-phase (χ_M″) signals are present in the alternating current (AC) susceptibility.     

Synthesis and some properties of substituted, 4, 5-cyclopentano-Δ2-isoxazolines

The 1, 3-dipolar cycloaddition of acetonitrile oxide and ethyl cyanoformate oxide to cyclopentenone and the structure and some of the properties of the resulting ²-isoxazolines were studied.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 625–628, May, 1976.     

Synthesis and ionic conductivity of mixed substituted polysiloxanes with oligoethyleneoxy and cyclic carbonate substituents

New comb polysiloxanes with mixed substituents were synthesized by hydrosilylation of PMHS with 4-allyloxymethyl-[1,3]dioxolan-2-one and tri(ethylene glycol) allyl methyl ether (AMPEO₃). The effect of the incorporation of carbonate groups on ionic transport, viscosity and thermal properties has been investigated. When doped with lithium bis(trifluorosulfonyl) imide, LiTFSI, the mixed substituted polysiloxane polymers with varying carbonate content all exhibited conductivity higher than those for the polysiloxanes with pure carbonate or pure oligoethyleneoxy substituents. The maximum ambient conductivity in this series was 1.62× 10⁻⁴ S/cm, occurring for the polymer containing 8.5% polar carbonate groups at a doping level of EO/LiTFSI = 15. The impedance measurement results showed that polymers containing larger amounts of carbonate groups exhibited lower conductivity, probably because of their increased viscosity and higher glass transition temperature. The conduction mechanism for these new comb polymers obeys free volume theory, as indicated by conductivity data fit to the VTF equation. We dedicate this paper to Professor Dick Jones, polysilane pioneer and valued friend.