X-ray molecular structure and theoretical study of 1,4-bis[2-cyano-2-(o-pyridyl)ethenyl]benzene

The structural characterisation of the molecule 1,4-bis[2-cyano-2-(o-pyridyl)ethenyl] benzene obtained through Knoevenagel condensation is reported. The single crystals, as light brown rods, were cultured from a chloroform solution using a slow evaporation method at ambient temperature. The compound crystallised in the monoclinic system belonging to the C2/c space group with a = 26.4556(9) Å, b = 3.73562(10) Å, c = 18.4230(6) Å, β = 109.841(4)° and the asymmetric unit comprising Z = 4. The structure is ordered and the molecules of the title compound exhibited a lattice with water molecules located at sites of inversion and two-fold axial symmetries. Thus, only halves of the molecules are symmetrically independent. The lattice is reported and contrasted with X-ray single-crystal diffraction and theoretical calculations of 1,4-bis(1-cyano-2-phenylethenyl)benzene. By using density functional theory (DFT) and second order Moller-Plesset (MP2) theoretical calculations, the ground state geometry in the whole molecule at the B3LYP/6-31+G(d,p), and MP2/6-31+G(d,p) theory levels, respectively, were optimised. The DFT calculations showed a quasi-planar structure of the molecule, whereas the wave function-based MP2 method afforded a non-planar optimised structure with significant torsion angles between the pyridine and phenyl rings.     

New viologen analogs: 1,4-bis[2-(pyridin-4-yl)ethenyl]benzene quaternary salts

Alkylation of 1,4-bis[2-(pyridin-4-yl)ethenyl]benzene with alkyl p-toluenesulfonates and dimethyl sulfate gave new viologen analogs, 1-alkyl-4-(2-{4-[2-(1-alkylpyridinium-4-yl)ethenyl]phenyl}ethenyl)-pyridinium bis(p-toluenesulfonates) and sulfate. Their derivatives with tetrafluoroborate and tetraphenylborate ions were also obtained. Spectral properties of the synthesized compounds were examined, and their structure was determined by X-ray analysis.     

Synthesis and Fluorescence of alt-Copoly[1, 4-divinylenebenzene／1, 4-bis（dimethylsilylene）benzene]

Silicon inserted n conjugated copolymer was synthesized by Heck reaction with moderate molecular weight. This silicon containing copolymer is thermally stable to 400℃, while emission of this polymer is blue-shifted compared with polyphenylenevinylene greenish emission. It shows potential application as organic emitter in OLED.     

Synthesis of aromatic polyethers by Scholl reaction. V. Synthesis and polymerization of 1,3-bis[4-(1-naphthoxy) benzoyl]benzene, 1,4-bis[4-(1-naphthoxy)benzoyl]benzene,bis[4-(1-naphthoxy)phenyl]methane, 1,3-bis[4-(1-naphthoxy) phenylmethyl]benzene,and 1,4-bis-[4-(1-naphthoxy)phenylmethyl]benzene

This article describes the synthesis and the cation-radical polymerization (Scholl reaction) of 1,3-bis[4-(1-naphthoxy) benzoyl] benzene ( 6 ) and 1,4-bis[4-(1-naphthoxy) benzoyl]- benzene ( 7 ) initiated by FeCI₃. This polymerization produced poly(ether ether ketone ketone)s (PEEKK) of number average molecular weight (M?_n) up to 5400 g/mol. The synthesis of bis[4-(1-naphthoxy) phenyl] methane ( 8 ), 1,3-bis[4-(1-napthoxy) phenylmethyl] benzene ( 9 ), and 1,4-bis[4-(1-naphthoxy) phenylmethyl] benzene ( 10 ) are also described. Polyethers of M?_n up to 15400 g/mol at a FeCl₃/monomer molar ratio of 2/1 were obtained. An increased polymerizability of the monomers 9 and 10 containing two CH₂ groups versus that of the corresponding monomers containing two carbonyl groups ( 6 and 7 ) was observed. This enhanced polymerizability was explained based on the increased nucleophilicity of monomers 9 and 10 .     

Polymerization of Acrylonitrile Initiated by 1,4-Dimethyl-1,4-bis(p-nitrophenyl)-2-tetrazene

The polymerization of acrylonitrile (AN) initiated by 1,4-dimethyl-1,4-bis(p-nitrophenyl)-2-tetrazene (Ie) was studied in dimethylformamide (DMF) at high temperature. The polymerization proceeds by a radical mechanism. The rate of polymerization is proportional to [Ie]^0.64 and [AN]^1.36. The overall activation energy for the polymerization is 21.5 kcal/mole within the temperature range of 115-130°C. The chain transfer of Ie was also undertaken over the temperature range of 120-135°C. The activation parameters for the decomposition of Ie at 120°C are k_d = 2.78 × 10^?6 sec^?1, ΔH^? = 40.8 kcal/mole, and ΔS^? = 19.5 cal/mole-deg, respectively.     

Polymerization of Styrene Initiated by 1,4-Dimethyl-1,4-bis(p-anisyl)-2-tetrazene

Abstract

The polymerization of styrene (St) initiated by 1,4-dimethyl-1,4-bis(p-anisyl)-2-tetrazene (1a) was studied kinetically in benzene. The polymerization proceeds through a radical mechanism. The rate of polymerization is proportional to [1a]^0.5 and [St]^1.0. The overall activation energy for the polymerization is found to be 81.2 kJ/mol within the temperature range of 65 to 80°C. The activation parameters for the decomposition of 1a at 70°C are k_d = 1.88 × 10^?5s^?1, δH? = 133.1 kJ/mol, and δS? = 29.9 J/mol·deg.     

Structure and Spectroscopic Studies of 4,8-bis(2-Hydroxybenzyl)-cis-octahydro[1,4]-oxazino [3,2-b]-1,4-oxazine

The title compound 4,8-bis(2-Hydroxybenzyl)-cis-octahydro [1,4]-oxazino [3,2-b]-1,4-oxazine (1) has been synthesized by the reaction of N-(2-hydroxybenzyl)-2-amino-1-ethanol with glyoxal. This novel compound was characterized by elemental analysis, IR, and ¹H NMR. The structure was also confirmed by a single crystal X-ray study. The compound crystallizes in monoclinic C2/C space group with unit cell dimensions: a = 18.318(4), b = 8.6110(17), c = 13.267(3) Å, = 119.90(3), V = 1814.1(6) ų, Z = 4. The two fused six-membered rings in 1 adopt chairlike conformations slightly flattened around the nitrogen atoms. In the central fusion bond, the geometry is a staggered conformation, with the two angular hydrogen atoms in the cis positions with respect to the rings, the nitrogen atoms antiperiplanar to each other, while the oxygen atoms remain gauche to each other and antiperiplanar to the hydrogen atoms. The ring conformations in 1 have been discussed on the basis of the anomeric effects and the presence of two strong intramolecular hydrogen bonds between the phenolic hydrogens and the amino groups.     

Ammonolysis of 1,4-bis(dimethylchlorosilyl)benzene

The ammonolysis of 1,4-bis(dimethylchlorosilyl)benzene with ammonia forms heterocyclic compounds of low molecular weight. The main reaction product is the crystalline [CH₃)₂SiC₆H₄Si(CH₃)₂NH]₄, which polymerizes on heating with the formation of polymers possessing a relative viscosity of 0.15–0.4.     

Phosphorylation of 1,4-bis(hydroxymethyl)benzene

1,4-Bis(hydroxymethyl)benzene undergoes bisphosphorylation with P(NEt₂)₃ at room temperature. The reaction produces no cyclic structures.__________Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 440–442, February, 2005.     

Protonation of 1,4-bis(1-vinyl-2-pyrrolyl)benzene

In the reaction of 1,4-bis(1-vinyl-2-pyrrolyl)benzene with hydrogen chloride and hydrogen bromide the hydrogen halide adds at the vinyl groups, and -protonation takes place in both pyrrole rings. In reaction with the superacidic system HSO₃F+SbF₅ (in SO₂ClF) position 5 of one heterocycle and position 4 of the other are protonated with retention of the vinyl groups.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1041–1045, August, 1991.     

Polybenzoxazole from 1,4-bis(trichloromethyl)benzene

High molecular weight poly(phenylenebenzobisoxazole) (PBO) was synthesized from 1,3-diamino-4,6-dihydroxybenzene dihydrochloride (1) and 1,4-bis(trichloromethyl)benzene (3) in polyphosphoric acid (PPA) or a mixture of PPA and methanesulfonic acid. When PPA was used as the solvent, 3 was first converted in situ to terephthalic acid before 1 was added to minimize degradation of 1. Compound 3 did not need to be sealed from atmospheric moisture because the trichloromethyl groups were not moisture sensitive. It was not necessary to use micronized 3. Adjustment of P₂O₅ content was optional for this reaction because no water was liberated from the condensation of 1 and 3. © 1997 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 35 : 2143–2145, 1997     

Synthesis of 1, 2-bis(b-amino-o-carboranyl)ethane and 1,4-bis(b-amino-o-carboranyl)benzene

Conclusions 1,2-Bis(B-amino-o-carboranyl)ethane and 1,4-bis(B-amino-o-carboranyl)benzene were synthesized.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 7, pp. 1669–1670, July, 1976.     

2,5-Dimethoxy-1,4-bis[2-(2,4-dimethoxyphenyl) ethenyl]benzene studied by quantum chemical calculations and single crystal X-ray diffraction

The configurational isomers of 2,5-dimethoxy-1,4-bis-[2-(2,4-dimethoxyphenyl)ethenyl]benzene have been investigated by ab initio (4-21G level) and MOPAC-AM1 semiempirical methods. The calculations were guided by and compared with single crystal X-ray results of the trans,trans-isomer determined at 298 K and 103 K. The barriers of rotation of the latter isomer in the free and the solid state were enumerated. A comparison with related molecules, in particular 1,4-bis[2-(3,4,5-trimethoxyphenyl)ethenyl]benzene, is made. The positioning of substituents is shown to be of importance for ring rotational movements and NMR shifts, as well as for UV /Vis spectroscopy. © 1996 by John Wiley & Sons, Inc.     

Microwave-assisted synthesis of 1,4-bis(difluoromethyl)benzene

A fast, mild, and practical microwave-assisted protocol for synthesis of 1,4-bis(difluoromethyl)benzene from 1,4-bis(dichloromethyl)benzene and KF was developed. The new protocol increased the yield and reduced the reaction time significantly in contrast to the conventional heating procedure. Also, the synergistic effect of a composite phase transfer catalyst was studied.     

Synthesis of 2-amino-4,4-bis(trifluoromethyl)-3-cyano-1,4-dihydrobenzo[h]-quinoline

Conclusions The reactions of -naphthylamine with 2,2-bis(trifluororaethyl)-1,1-dicyanoethylene leads to the formation of 2-amino-4,4-bis(trifluoromethyl)-3-cyano-1,4-dihydrobenzo[h]quinoline. The structure of this product was established by x-ray diffraction structural analysis.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 8, pp. 1917–1920, August, 1988.     

2-[2-(1,4-benzodioxanyl) ]-2-imidazoline hydrochloride

A new synthesis of 2-[2-(1,4-benzodioxanyl)]-2-imidazoline hydrochloride from 2-cyano-benzodioxan is described and the previously claimed route to this compound is shown to give a formula isomer, ie. 2-methyl-2-[2-(1,3-benzodioxolyl)]-2-imidazoline hydrochloride.