Synthesis and photoconductivity study of phthalocyanine polymers. IV. [SiPcNHCH2CH2NH]n

The preparation of a novel polymer of ethylenediamine bridged polymeric silicon phthalocyanine ( I ) with quasi-one-dimensional structure is described. The product was obtained by the condensation polymerization of ethylenediamine and silicon dichloride phthalocyanine (Cl₂SiPc) monomers and was characterized by IR and UV/VIS spectroscopy and elemental analysis. The photoconductivity of the polymer I with the quasi-one-dimensional structure is much better than that of not only the corresponding Cl₂SiPc monomer, but also other phthalocyanine polymers whose molecules are not one-dimensional structures, and showing the one-dimensional effects of molecular structure of increasing photoconductivity. © 1997 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 35: 959–964, 1997     

Synthesis and photoconductivity study of phthalocyanine polymers. II. PVK-co-CuPc (COOH)3

Cu-phthalocyanine diimide (Cu-diPc) was synthesized from a mixture of phthalic anhydride and pyromellitic dianhydride. By the hydrolysis of Cu-diPc, Cu-4,4′,5,5′-tetracarboxy-phthalocyanine (Cu-taPc) was obtained. A novel polymer of polyvinylcarbazole-bonded CuPc(COOH)₃ ( I ) was synthesized by the Friedel–Crafts reaction of polyvinylcarbazole (PVK) with Cu-phthalocyanine-4,4′,5,5′-tetraacid chloride. Polymer ( I ) contains ca. 5 mol % CuPc(COOH)₃ rings, which are covalently bonded to PVK. Polymer ( I ) shows good photoconductivity, which is much better than that of the corresponding phthalocyanine monomers. The factors that influence the photoconductivity, such as the thickness of IFL, and the types and proportion of CTM, were also studied. © 1993 John Wiley & Sons, Inc.     

Synthesis and characterization of a novel reactive ladderlike 4,4′‐phenylene ether‐bridged polyvinylsiloxane

A novel soluble, reactive ladderlike 4,4′‐phenylene ether‐bridged polyvinylsiloxane (L) was synthesized successfully for the first time by a stepwise coupling polymerization (SCP) including hydrolysis and polycondensation. The monomer, 4,4′‐bis(vinyldimethoxysilyl)phenylene ether (M), was synthesized by Grignard reaction. The structures of the monomer and the polymer were characterized by infrared spectrometry (IR), nuclear magnetic resonance (¹H NMR, ¹³C NMR, ²⁹Si NMR), mass spectrometry (MS), differential scanning calorimetry (DSC), X‐ray diffraction (XRD), and gel permeation chromatography (GPC). It is proposed from the characterization data that the polymer possesses an ordered ladderlike structure. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 2702–2710, 2000     

Computational study of energetic nitrogen‐rich derivatives of 1,1′‐ and 5,5′‐bridged ditetrazoles

Density functional theory method was used to study the heats of formation (HOFs), electronic structure, energetic properties, and thermal stability for a series of bridged ditetrazole derivatives with different linkages and substituent groups. The results show that the ? N₃ group and azo bridge (? N?N? ) play a very important role in increasing the HOF values of the ditetrazole derivatives. The effects of the substituents on the HOMO–LUMO gap are combined with those of the bridge groups. The calculated detonation velocities and detonation pressures indicate that the ? NO₂, ? NF₂, ? N?N? , or ? N(O)?N? group is an effective structural unit for enhancing the detonation performance for the derivatives. An analysis of the bond dissociation energies for several relatively weak bonds suggests that the N? N bond in the ring or outside the ring is the weakest one and the N? N cleavage is possible to happen in thermal decomposition. Overall, the ? CH₂? CH₂? or ? NH? NH? group is an effective bridge for enhancing the thermal stability of the bridged ditetrazoles. Because of their desirable detonation performance and thermal stability, five compounds may be considered as the potential candidates of high‐energy density materials (HEDMs). These results provide basic information for the molecular design of novel HEDMs. © 2011 Wiley Periodicals, Inc. J Comput Chem, 2011     

Synthesis and characterization of poly(arylene ether)s derived from 4,4′‐bishydroxybiphenyl and 4,4′‐bishydroxyterphenyl

A series of poly(arylene ether)s were successfully prepared by aromatic, nucleophilic substitution reactions with various perfluoroalkyl‐activated bisfluoromonomers with 4,4′‐bishydroxybiphenyl and 4,4′‐bishydroxyterphenyl. 4,4′‐Bishydroxyterphenyl was synthesized through the Grignard coupling reaction of magnesium salt of 4‐bromoanisole with dibromobenzene followed by demethylation with pyridine–hydrochloride. The products obtained by the displacement of fluorine atoms exhibited good inherent viscosity, up to 0.77 dL/g, and number‐average molecular weights up to 69,300. These poly(arylene ether)s showed very good thermal stability, up to 548 °C for 5% weight loss according to thermogravimetric analysis under synthetic air, and high glass‐transition temperatures, up to 259 °C according to differential scanning calorimetry, depending on the exact repeat unit structure. These polymers were soluble in a wide range of organic solvents, such as N‐methylpyrrolidone, dimethylformamide, tetrahydrofuran, toluene, and CHCl₃, and were insoluble in dimethyl sulfoxide and acetone. Thin films of these poly(arylene ether)s showed good transparency and exhibited tensile strengths up to 132 MPa, moduli up to 3.34 GPa, and elongations at break up to 84%, depending on their exact repeating unit structures. These values are comparable to those of high‐performance thermoplastic materials such as poly(ether ether ketone) (PEEK) and Ultem poly(ether imide) (PEI). These poly(arylene ether)s exhibited low dielectric constants. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 40: 55–69, 2002     

Enolethers. XXI. Synthesis of 5,5′-disubstituted 4,4′-bipyrimidines

1,6-Dialkoxy-3,4-diones 3 are easily accessible by acylation of enol ethers 1 with oxalyl chloride and subsequent elimination of hydrogen chloride using triethylamine. The open-chain 2,5-dimethyl derivative 3b is converted with amidines 4a-c and S-methylisothiourea (4d) , respectively, to give 2,2′-disubstituted 5,5′-dimethyl-4,4′-bipyrimidines 5a-d . The dihydrofuran and dihydropyran derivatives 3c and 3d , however, react with benzamidine (4c) in dimethylformamide only in the presence of calcium hydride as condensation agent yielding 5,5′-bis(2-hydroxyethyl)- and 5,5′-bis(3-hydroxypropyl)-2,2′-diphenyl-4,4′-bipyrimidine 6a and b.     

Mass spectral fragmentation pattern of 4,4′-bipyridines. Part II. 4,4′-oxybispyridine and 4,4′-thiobispyridine

The mass spectra of 4,4′-oxybispyridine and 4,4′-thiobispyridine are reported. In the former the base peak is due to the molecular ion and the fragmentation routes involve loss of H, CO, HCN, C₂H₂N and C_sHO from the molecular ion as well as rupture of the central bonds. In the latter the base peak is also due to the molecular ion and the fragmentation routes involve loss of H, CS, S, HCN and C₂HS as well as central bond rupture.     

Synthesis,characterization, and electrical properties of a diazodiphenylene‐bridged Cu–phthalocyanine polymer

A diazodiphenylene‐bridged Cu–phthalocyanine polymer was synthesized from the diazonium salt of bensidine and the Cu(II) 1,8,15,22‐tetraaminophthalocyanine complex and characterized with Fourier transform infrared, ultraviolet–visible spectroscopy, and elemental analysis. The polymer was partially soluble in organic solvents such as dimethylformamide and tetrahydrofuran. The molecular weight of the soluble part of the polymer was investigated with ebullioscopy and viscosimetry methods in tetrahydrofuran. Both methods showed that the molecular weight of the polymer was much larger than that of the complex. The conductivity of the samples was measured with a four‐prop conductivity measuring device. Iodine and hydrogen chloride were doped to the polymer, and an increase of about 10⁴ S cm^?1 in the electrical conductivity was observed. The cyclic voltammogram of the diazodiphenylene‐bridged Cu–phthalocyanine polymer in contact with a LiClO₄ electrolyte exhibited two reductions and two reoxidations with high reversibility and electrochemical stability. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 5692–5698, 2006     

Synthesis and characterization of photosensitive polyimides from methylthiomethyl-substituted 4,4′-diaminodiphenylmethanes and 3,3′,4,4′-benzophenonetetracarboxylic dianhydride

A series of novel polyimides are synthesized by the reaction of 3,3′,4,4′-benzophenonete-tracarboxylic dianhydride (BTDA) with four methylthiomethyl-substituted aromatic diamines: 3-methylthiomethyl-4,4′-diaminodiphenylmethane ( I ), 3,3′-dimethylthiomethyl-4,4′-diaminodiphenylmethane ( II ), 3,3′,5-trimethylthiomethyl-4,4′-diaminodiphenylmethane ( III ), and 3,3′,5,5′-tetramethylthiomethyl-4,4′-diaminodiphenylmethane ( IV ) in refluxing m-cresol. The polyimide of diamine I and BTDA carrying only one pendant methylthiomethyl group in a repeating unit is readily soluble in m-cresol, chloroform, and polar aprotic solvents. Increasing the number of the pendant group results in higher solubility. These fully imidized polyimides are also intrinsically photosensitive. The fraction of photoreactive benzophenone sites that relates to the rate and degree of completion of photocrosslinking reaction increases systematically with the increase of the pendant group content. As the average number of the pendant group in a repeating unit reaches 3, 63% of benzophenone sites are found to be photoreactive. These methylthiomethyl-substituted polyimides possess moderate tensile strength which falls in the range of 67–81 MPa. As a result of the increase of methylthiomethyl content, this type of polyimide reveals higher glass transition temperature but lower thermal stability due to the considerable dimension of the pendant group and the ready cleavage nature of the C? S bond. © 1993 John Wiley & Sons, Inc.     

The synthesis and thermal polymerization of 4,4′-diethynylphenyl ether

Diethynylphenyl ether (DEPE) was synthesized and its thermal polymerization studied by NMR, IR, and DSC techniques. DEPE is a crystalline solid that melts at 72–73°C and undergoes polymerization beginning at about 150°C. The heat of polymerization measured by DSC was 53 ± 2 kcal/mole. Thermomechanical analysis (TMA) of the fully cured resin showed softening behavior at temperatures in excess of 400°C. Weight loss up to 720°C was only 21%. A mechanism of polymerization based on the analysis of IR and NMR data for party polymerized material below 300°C is proposed.     

Biselenienyl series. II. Synthesis and resolution of 2,2′-dinitro-3,3′-biselenienyl-4,4′-dicarboxylic acid

2,2′-Dinitro-3,3′-biselenienyl-4,4′-dicarboxylic acid (VI), the first recorded compound of the 3,3′-biselenienyl series, has been prepared and resolved into its optical antipodes by fractional crystallization of its brucine salt. On the basis of the quasi-racemate method of Fredga and the O.R.D. spectra, to the dextrorotatory acid is assigned the R configuration.     

Synthesis and properties of polyimides from 4,4′-binaphthyl-1,1′,8,8′-tetracarboxylic dianhydride

4,4′-Binaphthyl-1,1′,8,8′-tetracarboxylic dianhydride was synthesized from 4-chloro-1,8-naphthalic anhydride and polymerized with aromatic and pliphatic diamines in m-cresol or N-methyl-2-pyrrolidinone (NMP). The polyimides, except for two derived from p-phenylenediamine and hydrazine, are soluble in 1,1,2,2-tetrachloroethane and NMP. Their intrinsic viscosities ranged from 0.36 to 2.20 dL/g. The polymers showed excellent thermal and thermooxidative stabilities and displayed weak glass transition temperatures. Young's moduli of some polymer films were in the range of 2.5 and 5.4 GPa at 30°C. The aliphatic polyimides exhibited a stronger fluorescence than the aromatic polyimides. © 1995 John Wiley & Sons, Inc.     

Mass spectra of some tetrasubstituted 4,4′-biisoxazoles and 4,4′-methylendiisoxazoles

The behaviour of some tetrasubstituted 4,4′-biisoxazoles and 4,4′-methylendiisoxazoles under electron impact has been investigated by means of high and low resolution mass spectrometry. The determination of metastable transitions and accurate masses of important fragment ions has led to the construction of fragmentation schemes. Specific skeletal rearrangement processes are discussed and it is proposed that they proceed through azirine and oxazole intermediates.     

Synthesis,Characterization, and Magnetic Behaviour of Dinuclear Nickel(II) Complexes of N,N′‐Substituted Dithiooxamides derived from α‐Amino Acids

New dinuclear complexes of the types [Ni₂(L)(H₂O)₂] and [Ni₂(L)(H₂O)₆] [H₄L = N,N′‐bis(carboxymethyl) dithiooxamide (H₄GLYDTO), N,N′‐bis(1‐carboxyethyl) dithiooxamide (H₄ALADTO), N,N′‐bis(1‐carboxy‐2‐methylpropyl) dithiooxamide (H₄VALDTO) and N,N′‐bis(1‐carboxy‐3‐methylbutyl) dithiooxamide (H₄LEUDTO)] have been prepared and characterized by IR and electronic absorption spectroscopy, and the structure of [Ni₂(ALADTO)(H₂O)₆] crystals has been determined by single crystal X‐ray analysis. This compound is composed of discrete dinuclear units in which two Ni^II atoms with NO₄S kernels are linked by a single [ALADTO]^4– group that coordinates through its carboxylato oxygen, amino nitrogen and thiolato sulphur atoms. In each dimer unit the two nickel(II) ions in distorted octahedral coordination are separated by 5.863(2) Å The temperature dependence of the magnetic susceptibility of the new compounds was measured over the range 2 to 300 K. In the complexes of [GLYDTO]^4– and [ALADTO]^4– the two Ni atoms are antiferromagnetically coupled, with J = –23.51(4) and –20.95(8) cm^–1, respectively. By constrast, [Ni₂(VALDTO)(H₂O)₂], [Ni₂(VALDTO)(H₂O)₆] and [Ni₂(LEUDTO)(H₂O)₂] remain paramagnetic down to 2 K, with magnetic moment values between 2.8 and 3.3 M.B.     

Diheterocyclic compounds from dithiocarbamates and derivatives thereof. V. 4,4′-dioxo-2,2′-dithioxo(dioxo)-6,6′-biquinazolines

The title compounds 3, 5 and 9 were synthesized in a one step procedure from dithiocarbamates 2 or dithiocarbonimidates 7 in medium to high yields. The usefulness of 2 and 7 as synthetic equivalents of unstable or unavailable isocyanates and isothiocyanates is also discussed.     

Heat-curable polyaromatic keto-ether-sulfones. XIV. More polymers with 2,2′-diphenylethynyl-4,4′-diphenyl units and their rearrangement products

Polymers were prepared from 4,4′-diphenoxydiphenylsulfone, isophthaloyl dichloride, and bis-p-phenoxyphenyl-4,4′-(2,2′-dibromodiphenyl)ketone, 2,2′-dibromodiphenyl-4,4′-dicarbonyl dichloride, or bis-p-phenoxyphenyl-4,4′-(2,2′-diphenylethynyldiphenyl)ketone in Friedel-Crafts type of polymerization. Bromine groups were subsequently replaced with phenylacetylene residues, and the polymers were cured at high temperatures, with the apparent formation of benzanthracene linkages. Cured polymers exhibited higher softening points, decreased solubilities, and, in some instances, higher melting points than their uncured precursors. Significant weight losses occurred during isothermal aging tests.     

Synthesis of difurazanyl ethers from 4,4′‐dinitroazoxyfurazan

Nonselective attacks at the carbon bonded to a nitro group and carbon bonded to the N(O) atom of the azoxy group were observed in the reactions of 4,4′‐dinitroazoxyfurazan with bases and nucleophiles. A mechanism is presented to account for both of the pathways to products. A series of new difurazanyl ether derivatives was synthesized. © 2000 John Wiley & Sons, Inc. Heteroatom Chem 11:48–56, 2000     

The First Total Synthesis of 4,4′-Biisofraxidin

Ｉｎｔｒｏｄｕｃｔｉｏｎ　　 4 ,4′ Ｂｉｉｓｏｆｒａｘｉｄｉｎ (1) ,ａｎｅｗｂｉｓｃｏｕｍａｒｉｎ ,1ｗａｓｉｓｏｌａｔｅｄｂｙＷａｎｃｈａｉＤｅ Ｅｋｎａｍｋｕｌａｎｄｈｉｓｃｏ ｗｏｒｋｅｒｓｆｒｏｍｔｈｅｒｏｏｔｃｕｌｔｕｒｅｓｏｆｉｍｐａｔｉｅｎｓｂａｌｓａｍｉｎａＬ . (Ｂａｌ ｓａｍｉｎａｃｅａｅ) ,ｗｈｉｃｈｈａｓｌｏｎｇｂｅｅｎｕｓｅｄｉｎＴｈａｉｌａｎｄａｓａｔｒａｄｉｔｉｏｎａｌｆｏｌｋｍｅｄｉｃｉｎｅ .ＴｈｅｌｅａｖｅｓｏｆＢａｌｓａｍｉｎａｃｅａｅａｒｅｕｓｕａｌｌｙｕｓｅｄｆ…