Synthesis and electrochemical characterization of dipyrroles separated by diphenyleneoxide and diphenylenesulfide spacers via the Trofimov reaction

4,4′-Bis[2-(1-vinylpyrrolyl)]diphenyloxide, 4,4′-bis(2-pyrrolyl)diphenylsulfide, 4-(2-pyrrolyl)-4′-[2-(1-vinylpyrrolyl)]diphenylsulfide and 4,4′-bis[2-(1-vinylpyrrolyl)]diphenylsulfide have been synthesized in a one-pot procedure from oximes of corresponding diacetylphenylenoxide and -sulfide through their reaction with acetylene in the MOH-DMSO systems (M=Li, K) at 80-130 °C under pressure of 10-15 atm, thus illustrating applicability and general character of the reaction of synthesis of diverse dipyrrole-phenylene assemblies and their N-vinyl derivatives. Two of the pipyrroles are promising for creating new conducting polymers with sulfur and oxygen atoms in the conjugation chain and for the study of the influence of the diphenyleneheteroatom moiety on conductivity of final polymer products. For the dipyrroles with the diphenyleneheteroatom moieties and 1,4-phenylene spacer the luminescence characteristics were determined.     

Localization of electronic excitation energy in Ru(2,2′-bipyridine)2(2,2′-bipyridine-4,4′-dicarboxylic acid)2+ and related complexes

The absorption spectra of Ru(2,2′-bipyridine)₂ (2,2′-bipyridine-4,4′-dicarboxylic acid)²⁺ (I) and its diethyl ester (II) are closely related and are both significantly different from the spectra of the mono-protonated (Ia) and deprotonated (Ib) complexes. Luminescence polarization measurements show that for I and II the luminescent states have the transferred electron in the bipy-4,4′(COOH)₂ and bipy-4,4′(COOEt)₂ ligands, respectively, rather than in the unsubstituted bipy ligands.     

Characterization of cobalt-modified polyimides

Modified polyimide films containing cobalt have been prepared by the addition of cobalt(II) chloride to a solution containing one of the diamines 4,4′-oxydianiline (ODA) or 4,4′-diaminodiphenylsulfide (DDS) and one of the dianhydrides 3.3′, 4,4′-benzophenonetetracarboxylic dianhydride (BTDA) or 4,4′-bis(3,4-dicarboxyphenoxy)diphenylsulfide dianhydride (BDSDA) and characterized by thermal methods, UV-visible spectra, room-temperature direct-current electrical resistivity measurements, and X-ray photoelectron and Auger electron spectroscopy. A principal goal of this work was to establish if there was coordination of the potential donor atoms of the polymide to cobalt. UV-visible spectra of the modified polyamic acid solutions and polyimide films and a titration study of a model system do not show any appreciable coordination with either the polyamic acid or the polyimide; rather, the cobalt(II) appears to be coordinated to the solvent, N,N-dimethylacetamide (DMAc), as [Co(DMAc)₄]²⁺, until the temperature is raised above 200°C. X-ray photoelectron spectra of films cured only to 200°C also do not show significant shifts in the binding energies of the potential donor atoms from those binding energies of the undoped polymers, confirming little direct coordination of the cobalt to atoms of the polyimide. Heating the films to 300°C in a forced-air oven causes the formation of a cobalt oxide layer on the air side of the polymer. Direct-current electrical resistivity measurements on this surface show a 10⁴–10⁶ reduction in resistivity due to this layer.     

4,4′-[1,n-亚烷基双[(E)-2-(4-氧苯基)乙烯基]]双吡啶的光化学性质

通过E-[4-[2-(4-羟基苯基)乙烯基]吡啶与1,n-二溴烷烃亲核取代反应合成了4,4′-[1,n-亚烷基双[(E)-2-(4-氧苯基)乙烯基]]双吡啶[n=2(Ia),3(Ib),4(Ic),6(Id)].用元素分析、红外、紫外和质子核磁共振谱鉴定了Ia～Id的结构.将Ia～Id的稀溶液用中压汞灯和低压汞灯交替照射,发现其分子内光环加成反应的存在,并且随着亚烷基碳链的延长,反应速度加快.研究还发现锌离子可以与吡啶环上氮原子发生螯合作用使分子内光环加成反应加快.本文化合物荧光很弱,在较高浓度下有较强分子间激基缔合物荧光.     

Rigid-rod polymers with polysiloxane side chains. 2. Synthesis and characterization of aromatic polybenzobisoxazoles with polysiloxane side chains and composite formation with polysiloxane matrices

Aromatic polybenzobisoxazoles, having polydimethylsiloxane side chains (SCPBOs), were prepared using terephthaloyl chloride-terminated polydimethylsiloxane macromonomers and 3,3′-bis(trimethylsiloxy)-4,4′-bis(trimethylsilylamino)biphenyl for the purpose of dispersing rigid-rod molecules in silicone matrices for molecular reinforcement. The degree of polymerization of the side chain was varied from 7.8 to 45.4, and a small amount of (3-butenyloxy)terephthaloyl chloride was copolymerized to give the polymers a functionality that can be linked to the matrices. For all the SCPBOs, the WAXD pattern showed only diffuse reflections, suggesting limited structural regularity, although the polymers were optically anisotropic. No melting transition was observed below the side chain decomposition temperature, 350°C. A polydimethylsiloxane/polybenzobisoxazole composite elastomer was obtained first curing the polysiloxane matrix containing the prepolymer of the SCPBO, followed by in situ thermal ring closure of the prepolymer. Some reinforcement was observed, but the presence of plasticizing effect by the unbound SCPBO was suggested at the same time. © 1995 John Wiley & Sons, Inc.     

Thermal degradation of polyurethanes by hexamethyldisilazane: Syntheses of polyhexamethyleneurea with organosilicon reagents

Representative aliphatic and aromatic polyurethanes undergo degradation upon treatment with hexamethyldisilazane (HMDS) at elevated temperatures. The course of the reaction is dependent on the nature of the polyurethane. Thus heating poly-[ethylene methylene bis(4-phenylcarbamate)] with HMDS in a sealed tube at 197°C gives high yields of 4,4′-diaminodiphenylmethane, trimethylisocyanatosilane, and 1,2-bis(trimethylsiloxyethane) along with lesser amounts of hexamethyldisiloxane, bis-(trimethylsilyl)carbodiimide, and ammonia. Under the same conditions, poly(ethylene N,N′-hexamethylenedicarboxylate) gives no diamine, but good yields of polyhexamethyleneurea and 1,2-bis(trimethylsiloxy)ethane together with smaller quantities of the other named products are obtained. In the course of this study, two novel routes to polyalkyleneureas were developed. For example, polyhexamethyleneurea is obtained in good yield by treatment of 1,6-hexanediamine with trimethyklisocyanatosilane at elevated temperatures in a sealed tube. The reaction of 1,1′-hexamethylenediurea with HMDS under these conditions results in formation of the same product. A mechanism rationalizing the foregoing results is proposed which involves initial nucleophilic attack by HMDS on the polyurethane to give an intermediate disilylated urea. Thermal decomposition of this intermediate by alternative routes would give the observed products.     

Synthesis of 4,4′-bis(dichloroamino)- and 4,4′-bis(chloroamino)-3,3′-azofurazans,the first representatives of dichloroamino- and chloroaminofurazans

First representatives of dichloroamino- and chloroaminofurazans, viz., 4,4′-bis(dichloroamino)- and 4,4′-bis(chloroamino)-3,3′-azofurazans, were synthesized by the chlorination of 4,4′-diamino-3,3′-azofurazan with sodium hypochlorite in the CH₂Cl₂—H₂O mixture.     

Far-IR spectra of charge-transfer complexes between IX (X = Cl,Br or I) and trans-1,2-bis(4-pyridyl)ethylene, 1,2-bis(4-pyridyl)ethane and 4,4′-

Far-IR spectra of charge-transfer complexes of trans-1,2-bis(4-pyridyl)ethylene (Bpe), 1,2-bis(4-pyridyl)ethane (Bpa) and 4,4′-bipyridyl (4,4′-     

Synthesis and properties of luminophores derived from fluorinated biphenyls

A procedure was developed for the synthesis of dimethyl 2-fluoro-and 2,2′-difluorobiphenyl-4,4′-dicarboxylates. The latter were converted into fluorinated 4,4′-bis[(E)-2-(1,3-benzoxazol-2-yl)ethenyl]-and 4,4′-bis[5-(4-octyloxyphenyl)-1,3,4-oxadiazol-2-yl]biphenyls which showed strong luminescence in the crystalline state and in solution; their spectral properties were examined.     

Polymerization systems driven by aromatization energy: Anionic polymerization of 4-allylidene-2,6-dimethyl-2,5-cyclohexadien-1-one and spiro[2,5]octadienone derivatives

To investigate the polymerization systems driven by aromatization energy, 4-allylidene-2,6-dimethyl-2,5-cyclohexadien-1-one ( Ia ), 5,7-dimethyl-1-vinylspiro[2,5]octa-4,7-dien-6-one ( Ib ), 4,7-dimethyl-1-vinylspiro[2,5]octa-4,7-dien-6-one [ Ic ], 2-vinyl-2′-methylspiro[cyclopropane-1,4′-(1′-naphthalenone)] ( Id ), and 2-phenyl-2′-methylspiro[cyclopropane-1,4′-(1′-naphthalenone)] ( Ie ) were prepared and polymerized with sodium cyanide in N,N-dimethylformamide. Monomer Ia was highly polymerizable even at ?65°C. Monomers Ib–Ie also polymerized well, giving powdery polymers that were soluble in common solvents. All the polymerizations took place through the aromatization of the cyclohexadienone ring, suggesting that the aromatization energy is the driving force for the polymerization of these monomers.     

巯甲基二苯甲酮的合成

以NaI为催化剂,以4-溴甲基二苯甲酮或4,4’-二(溴甲基)二苯甲酮为原料,采用硫脲法合成了4-巯甲基二苯甲酮(新化合物,产率75%)或4,4’-二(巯甲基)二苯甲酮(产率83%),其结构经1H NMR,13C NMR,IR和元素分析表征。     

N-methyl-substituted aromatic polyamides

A series of N-methyl-substituted aromatic polyamides derived from the secondary aromatic diamines 4,4′-bis(methylamino)diphenylmethane, 3,3′-bis(methylamino)diphenylmethane, 4,4′-bis(methylamino)benzophenone or 3,3′-bis(methylamino)benzophenone and isophthaloyl dichloride, and terephthaloyl dichloride or 3,3′-diphenylmethane dicarboxylic acid dichloride was prepared by high-temperature solution polymerization in s-tetrachloroethane. Compared with analogous unsubstituted and partly N-methylated aromatic polyamides, the full N-methylated polyamides exhibited significantly lower glass transition temperatures (T_g), reduced crystallinity, improved thermal stability, and good solubility in chlorinated solvents.     

Synthesis and properties of poly(imide-sulfonate)s

Polycondensations of N,N′-bis(hydroxyalkyl)pyromellitic diimides, N,N′-bis(hydroxyphenyl)-pyromellitic diimides, N,N′-bis(hydroxyalkyl)-3,3′,4,4′-benzophenonetetracarboxylic diimides and N,N′-bis(hydroxyphenyl)-3,3′-4,4′-benzophenonetetracarboxylic diimides with aromatic disulfonyl chlorides were carried out in pyridine to produce poly(imide-sulfonate)s. The resulting polymers had inherent viscosities in the range of 0.25–0.38 dL/g. These poly(imide-sulfonate)s were insoluble in common organic solvents and had relatively good thermal stability. The TGA data showed 10% weight losses at 253–365°C and residual weights at 500°C were 22–72% in nitrogen.     

Synthesis and Characterization of Poly(Aryl Ether-Bissulfone)s

A series of poly(aryl ether-bissulfone)s were synthesized from bis-phenols, 4,4′-bis(4-chlorophenylsulfonyl)biphenyl, and 4,4′-bis(4-fluorophenylsulfonyl)biphenyl. The bishalide monomers were synthesized by reaction of 4,4′-bis(chlorosulfonyl)biphenyl with a suitable aryl halide. Potassium carbonate mediated reaction in di-methylacetamide gave high molecular weight polymers in excellent yield. The polymers are soluble in dipolar aprotic solvents. Unlike the corresponding monosulfone analogues, the poly(aryl ether-bissulfone)s exhibited poor solubility in chlorinated hydrocarbons. The glass transition temperatures of the polymers are among the highest known for poly(aryl ether)s (241-271 °C). In addition, the polymers exhibit excellent thermal stability and they produce clear, colorless tough films by solution casting or compression molding.     

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.     

Synthesis of polymer intermediates containing the hexafluoroisopropylidene group via functionalization of 2,2-diphenylhexafluoropropane

The title compound was synthesized by hydrogenolysis of its precursor 2,2-bis(4-trifluoromethanesulfonatophenyl)hexafluoropropane ( 2 ) in the presence of a base. 2,2-Diphenylhexafluoropropane ( 6 ) can be appropriately functionalized at the 3,3′-positions to give the diamino ( 7 ), dibromo ( 11 ), dicarboxaldehydo ( 13 ), 3-ethynyl-3′-carboxaldehydo ( 14 ) derivatives which are important monomers in the synthesis of various high-temperatures resistant polymers and oligomers containing the hexafluoroisopropylidene (6F) group. 2,2-Bis(4-triflatophenyl)hexafluoropropane ( 2 ) undergoes quantitative dinitration at the 3,3′-positions to yield 2,2-bis(3-nitro-4-triflatophenyl)hexafluoropropane ( 3 ) which ultimately leads to the 3,3′-diamino-4,4′-bis(arylamino) ( 5 ) and 3,3′-diamino-4,4′-dihydroxy ( 8 ) derivatives which are specifically designed for phenylbenzimidazole, benzimidazoquinazoline, and benzoxazole polymers and oligomers.     

Synthesis,structure, and complexing ability of fluoroalkyl-containing 2,2′-(biphenyl-4,4′-diyldihydrazono)bis(1,3-dicarbonyl) compounds

New fluoroalkyl-containing 2,2′-(biphenyl-4,4′-diyldihydrazono)bis(1,3-diketones) and 2,2′-(biphenyl-4,4′-diyldihydrazono)bis(3-oxopropionates) were synthesized by azo coupling of the corresponding 1,3-dicarbonyl compounds with biphenyl-4,4′-bis(diazonium) dichloride. Complexing ability of the obtained bis-hydrazones was studied, and new coordination compounds of the general formula M₂L₂ [where M = Ni(II), Cu(II); L = fluoroalkyl-containing 2,2′-(biphenyl-4,4′-diyldihydrazono)bis(1,3-diketone)] were obtained.     

Design of postmetallocene Schiff base-like catalytic systems for polymerization of olefins: XII. Synthesis of tetradentate bis-salicylaldehyde imine ligands

Reactions of salicylaldehyde, 3-tert-butylsalicylaldehyde, and 3,5-di-tert-butylsalicylaldehyde with 1,4-diaminobutane, 1,6-diaminohexane, 4,4′-diaminodiphenylmethane, 4,4′-diamino-3,3′,5,5′-tetramethyldiphenylmethane, 4,4′-diamino-5,5′-dicyclopentyl-3,3′-dimethyldiphenylmethane, 4,4′-diamino-5,5′-dicyclohexyl-3,3′-dimethyldiphenylmethane, bis(4-aminophenyl) sulfone, o,o′- and p,p′-diaminodiphenyl ethers, 1,4-bis(4-aminophenoxy)benzene, 2,2-bis[4-(4-aminophenoxy)phenyl]propane, and 4,4″-diamino-p-terphenyl gave a series of the corresponding Schiff bases which can be used as tetradentate ligands for the synthesis of titanium and zirconium complexes.     

Reaction of guanosine derivatives with phosphorus trichloride in acetone

2′, 3′-Di-O-protected guanosine derivatives (Ia and Ib) were allowed to react with phosphorus trichloride in acetone to give the N²-(1-methyl-1-phosphono)ethylguanosine derivatives (IIIa and IIIb).     

Addition polyimides. III. Thermal behavior of bismaleimides

This article describes the synthesis of N,N′-bis(3,3′-maleimidophenyl) sulfone (S) and its Michael addition products with (4,4′-diaminodiphenyl) methane (S-M), 4,4′-diaminodiphenyl ether (S-E), (3,3′-diaminodiphenyl) sulfone (S-DDS_m), (4,4′-diaminodiphenyl) sulfone (S-DDS_p), (3,3′,3″-tris aminophenyl) phosphine oxide (S-TAP), and 9,9-bis(p-aminophenyl) fluorene (S-B). Curing behavior of these bisimides was investigated by differential scanning calorimetry. Activation energy of curing reaction was determined by using isothermal and multiple heating rate method. Thermal stability of bisimides was evaluated by thermogravimetric analysis. Better char yields were obtained in S-TAP resins.