Synthesis and photophysical properties of novel organo-soluble polyarylates bearing triphenylamine moieties

Two series of new blue photoluminescent aromatic polyesters (polyarylates) were synthesized from 4,4′-dicarboxytriphenylamine and 4,4′-dicarboxy-4″-methyltriphenylamine with various bisphenols by the diphenylchlorophosphate (DPCP) activated direct polycondensation in a medium of pyridine and lithium chloride. These polymers were amorphous and readily soluble in various common organic solvents including DMAc, THF, and chloroform, and could be cast from their chloroform solutions into transparent films due to their excellent solubility. These polyarylates exhibited moderately high T _g values (186–264 °C) and thermal stability. In THF solution, these triphenylamine-containing polyarylates showed UV-Vis absorption bands at 359–365 nm and photoluminescence peaks around 427–451 nm in the blue region. Figure Two series of new blue photoluminescent aromatic polyesters (polyarylates) were synthesized from 4,4’-dicarboxytriphenylamine and 4,4’-dicarboxy-4”-methyltriphenylamine with various bisphenols by the diphenylchlorophosphate (DPCP) activated direct polycondensation in a medium of pyridine and lithium chloride. These polymers were amorphous and readily soluble in various common organic solvents including DMAc, THF, and chloroform, and could be cast from their chloroform solutions into transparent films due to their excellent solubility. These polyarylates exhibited moderately high Tg values (186-264 oC) and thermal stability. All the PL spectra of these polymers showed a blue shift when the solvent was changed from NMP to THF or chloroform. Solvation should increase the interaction between polymer chain and solvent, which may consume certain excitation energy and lead to increase on the emission wavelength.     

Synthesis and characterization of aromatic polyamides derived from various derivatives of 4,4’-oxydianiline

Three aromatic diamines, 2,2′-diiodo-4,4′-oxydianiline (DI-ODA 2), 2,2′-bis[p-(trifluoromethyl)phenyl]-4,4′-oxydianiline (BTFP-ODA 3) and 2,8-diaminodibenzofuran (DADBF 5) were synthesized by using 4,4-oxydianiline (4,4′-ODA) as the starting material. New aromatic polyamides 6, 7 and 8 were prepared from these three diamines and six commercially available aromatic diacids by direct polycondensation, respectively. Polyamides 6 and 7 contained bulky iodide and p-trifluoromethylphenyl substitutents that would hinder the chain packing and increase the free volume. They exhibited good optical transparency in visible light region and showed excellent solubility in organic solvents such as DMSO, DMAc, DMF and NMP. Polyamides 8 containing planar dibenzofuran moieties had the highest glass transition temperatures and decomposition temperatures among these polyamides. Polyamides 6 had the lowest decomposition temperatures due to the presence of weak carbon–iodine bond. All of these polyamides showed amorphous nature evidenced by wide angle X-ray diffraction. No endothermic peaks were observed from DSC thermograms up to their decomposition temperatures. High optical transparency and excellent solubility combined with good thermal stability make these polyamides attractive for potential soft electronics applications.     

Synthesis and characterization of novel polyamides derived from 1,4-bis((4-amino-2-(trifluoromethyl)phenoxy)methyl)cyclohexane and aromatic dicarboxylic acids

A new aromatic diamine with a trifluoromethyl pendent group, 1,4-bis((4-amino-2-(trifluoromethyl)phenoxy)methyl)cyclohexane, was successfully synthesized in two steps from 1,4-cyclohexanedimethanol and 2-chloro-5-nitrobenzotrifluoride as starting materials. And the newly obtained diamine with various aromatic dicarboxylic acids, including isophthalic acid (IPA), 2,2-bis(4-carboxy-phenyl)hexafluoropropane (6FA) and 4,4′-oxydibenzoic acid (OBA), were polymerized, respectively via the usual Yamazaki reaction to prepare a series of fluorinated polyamides. The resulting polymers had inherent viscosities ranging from 1.85 to 2.36 dL/g. All the polymers showed outstanding solubility and could be easily dissolved in amide-type polar aprotic solvents [e.g., N-methyl-2-pyrrolidone (NMP), DMAc, and DMF] and even dissolved in less polar solvents (e.g., pyridine, and tetrahydrofuran). These polymers could also be easily be cast into transparent, tough and flexible films with tensile strengths of 76.5–82.3 MPa, Young’s moduli of 1.64–1.85 GPa, and elongations at break of 10–12%. In addition, these polyamides films exhibited low dielectric constants of 2.37–2.53 at 100 MHz, low water absorptions in the range of 1.54–2.13%, and high transparency with an ultraviolet–visible absorption cut-off wavelength in the 326–333 nm range. Furthermore these polyamides still retained good thermal stability. These combined outstanding features make these obtained polyamides competitive for advanced microelectronic applications.     

New soluble triphenylamine-based amorphous aromatic polyamides for high performance blue-emitting hole-transporting and anodically electrochromic materials

A newly 4-methoxy-substituted triphenylamine-containing aromatic diacid monomer, 4,4′-dicarboxy-4″-methoxytriphenylamine 2, with blue light (454 nm) fluorescence quantum efficiency 45% was successfully synthesized by the sodium hydride-mediated condensation of 4-methoxyaniline with 4-fluorobenzonitrile, followed by alkaline hydrolysis of the intermediate dicyano compound. A series of novel aromatic polyamides having strong fluorescence emissions in the blue region with high quantum yields up to 40% and one reversible oxidation redox couples at 1.08 V vs. Ag/AgCl in acetonitrile solution have been synthesized and characterized. They exhibited good thermal stability with 10% weight-loss temperatures above 460 °C under a nitrogen atmosphere with relatively high glass-transition temperatures (267-307 °C). All obtained polyamides revealed excellent stability of electrochromic characteristics, changing color from original pale yellowish to blue.     

Synthesis of high refractive index polyamides containing thioether unit

Two kinds of aromatic dibenzoyl chloride monomer containing thioether unit 4,4′-Bis(4-chloroformylphenylthio)benzophenone (BP-DC) and 4,4′-thiodibenzoyl chloride (T-DC) were synthesized with two steps, which was reacted with diamine monomer containing thioether and amide unit to prepare a new kind of polyamide containing high quantity thio-ether group. The intrinsic viscosity of the polyamides was 0.76–0.90 dl/g obtained with optimum synthesis conditions. The polymers were found to have good optical properties: the optical transmittance of the aromatic polyamide film at 450 nm is higher than 80%, meantime the high quantity thio-ether unit provided the polymer with a high refractive index ranging from 1.691 to 1.696 and low birefringence of 0.007–0.008. At the same time the polymers had excellent thermal performance with glass transition temperature (T_g) of 226 °C–278 °C, initial degradation temperature (T_d) of 427 °C–439 °C. They showed improved solubility in polar aprotic solvents.     

Highly Regioselective and Active Rhodium/Bisphosphite Catalytic System for Isomerization–Hydroformylation of 2-Butene

Abstract  

The formation of linear aldehyde from isomerization–hydroformylation of 2-butene represents an important subject and current task in industry. Both high activity and excellent regioselectivity were achieved in the rhodium-catalyzed 2-butene isomerization–hydroformylation with 2,2′-bis(dipyrrolylphosphinooxy)-1,1′-(±)-binaphthyl (1) as ligand. Bulky phosphite with electron-withdrawing pyrrol groups dramatically improved the selectivity of linear product, and a good yield of 90.5% aldehydes was obtained with an excellent linear aldehyde regioselectivity of 95.3% under optimized condition.     

Novel soluble fluorine-containing polyamides derived from 2-(4-trifluoromethylphenoxy)terephthalic acid and trifluoromethyl-substituted aromatic bis(ether amine)s

A series of new fluorine-containing polyamides were prepared directly by polycondensation of 2-(4-trifluoromethylphenoxy)terephthalic acid with four trifluoromethyl-substituted aromatic bis(ether amine)s in N-methyl-2-pyrrolidone (NMP) solution containing dissolved calcium chloride using triphenyl phosphite and pyridine as condensing agents. All the polymers showed excellent solubility in solvents such as NMP, N,N-dimethylacetamide, N,N-dimethylformamide, dimethyl sulfoxide, pyridine, tetrahydrofuran, and acetone at room temperature. These polymers had inherent viscosities between 0.67 and 1.09 dL/g, and their weight-average molecular weights and number-average molecular weights were in the range of 48,200–68,000 and 29,500–39,400, respectively. The resulting polymers showed glass-transition temperatures between 189 and 214 °C and 10% weight loss temperatures ranging from 475 to 483 °C, and char yields at 800 °C higher than 50% in nitrogen. All polymers were amorphous and could be cast into transparent, flexible, and strong films from DMAc solutions with tensile strengths of 71–115 MPa, elongations at break of 6–9%, and tensile moduli of 2.7–3.2 GPa. These polymers had low dielectric constants of 3.14–3.31 (1 MHz), low moisture absorption in the range of 0.88–1.60%, and high transparency with an ultraviolet–visible absorption cut-off wavelength in the 320–340 nm range.     

新型可溶性透明聚芳酰胺的合成与表征

以2-氯-5-硝基三氟甲苯和1,4-环己二醇为起始原料,通过两步有机反应合成了一种新的含氟二胺单体：1,4-双[4-胺基-2-(三氟甲基)苯氧基]环己烷;并由该二胺单体和对苯二甲酸、间苯二甲酸、4,4'-二苯醚二甲酸和2,2-双(4-羧基苯基)六氟丙烷经缩聚反应制备了一系列新型聚芳酰胺,其特性黏度在0.89~1.29 dL/g之间。该类聚芳酰胺表现出了优良的溶解性能和光学性能,室温下不仅可以溶于N-甲基-吡咯烷酮、N,N-二甲基乙酰胺、N,N-二甲基甲酰胺等强极性溶剂中,还能溶于低沸点的四氢呋喃、氯仿、二氯甲烷等溶剂中;由该类聚合物溶液所制的薄膜无色透明,截断波长在335~357 nm,在400 nm后具有高透明性。此外,该聚芳酰胺还表现出了良好的热学性能,玻璃化转变温度在202~223 ℃,氮气中10 %热失重温度在330~364 ℃。     

Syntheses and Characterizations of Three Cu(II) Complexes with 2,2′-Bipyridine-3,3′-dicarboxylate and <Emphasis Type="Italic">N</Emphasis>-Donor Ancillary Ligands

Abstract  

Three novel inorganic–organic hybrid frameworks of [Cu(BPDC)(2,2′-bipy)] (1), [Cu(BPDC)(BIB)₂ ·H₂O]_n (2) and [Cu(BPDC)(4,4′-bipy)]_n (3) (BPDC²⁻ = 2,2′-bipyridine-3,3′-dicarboxylate; 2,2′-bipy = 2,2′-bipyridine; BIB = 1,2-bis(imidazol-1-ylmethyl)benzene; 4,4′-bipy = 4,4′-bipyridine) were prepared. The three complexes have been characterized by the elemental analyses, IR spectra, TGA and the single crystal X-ray diffraction. Two intramolecular Cu(II) centers of 1 are encircled by two BPDC²⁻ ligands forming an 18-membered ring, which is further assembled into a three-dimensional (3D) supramolecular architecture through the C–H···O hydrogen-bonding interactions. Complex 2 possesses a two-dimensional layer network, while complex 3 is a three-dimensional polymer composed of Cu-BPDC helical chains bridged by 4,4′-bipy. In addition, the electrochemistry of complex 1 was investigated.     

Synthesis and characterization of soluble polyamides from bis-[(4′-aminobenzyl)-4-benzamide] ether and various diacids

New aromatic diamine containing preformed amide, ether, and methylene; bis-[(4′-aminobenzyl)-4-benzamide] ether (BABE), was synthesized and characterized by FT-IR, NMR, and mass spectrometry. Aromatic–aliphatic polyamides were prepared from BABE with aliphatic/aromatic diacids via Yamazaki’s polymerization. The polyamides were characterized by FT-IR, ¹H NMR, inherent viscosity [η_inh], solubility tests, differential scanning calorimetry [DSC], thermogravimetric analysis [TGA], and X-ray diffraction [XRD]. Polyamides had inherent viscosities 0.35–0.84 dL/g, soluble in aprotic polar solvents like N-methyl-2-pyrrolidone, N, N-dimethyl acetamide and dimethyl sulphoxide containing LiCl due to an amorphous to partially crystalline morphology; as XRD patterns indicated. DSC analysis of polyamides showed glass transition temperatures 166–268 °C. Polyamides showed high thermal stability as they did not degrade below 300 °C, had 10% weight loss temperature higher than 375 °C, and the char yields at 900 °C were 22–55%; indicating potential applications as engineering materials.     

Synthesis and properties of polyimides based on isomeric (4, 4′-methylenediphenoxyl) bis (phthalic anhydride)s (BPFDAs)

Isomeric (4, 4′-methylenediphenoxyl) bis (phthalic anhydride)s (BPFDAs)were synthesized and their structures were determined via IR spectra and ¹H NMR. Polyimides were then prepared from isomeric BPFDAs and aromatic diamines in N, N-Dimethylacetamide (DMAc) via the conventional two-step method. Polyimides based on 3, 3′-BPFDA are soluble in common organic solvents at room temperature, while polyimides based on 4, 4′-BPFDA were only partially soluble in high-boiling-point solvent even upon heating. The 5% weight-loss temperatures (T _5% ) of these polyimides were in the range of 430–500 °C in air. Dynamic mechanical thermal analysis (DMTA) indicated that the glass-transition temperatures of polyimides from 3, 3′-BPFDA are around 10–20 °C higher than those of polyimides from 4, 4′-BPFDA. The wide-angle X-ray diffraction showed that all polyimides are amorphous.     

Polyimides based on furanic diamines and aromatic dianhydrides: synthesis,characterization and properties

Novel polyimides containing furan moieties were prepared from the resulting furanic diamine monomers with various aromatic dianhydrides including 1,2,4,5-benzene-tetracarboxylic dianhydride, 3,3′,4,4′-biphenyltetracarboxylic dianhydride, 4,4′-oxydiphthalic anhydride, and hexafluoroisopropylidene 2,2-bis(phthalic anhydride), via a two-step process. The resulting polyimides were characterized by solubility tests, viscosity measurements, FTIR, ¹H NMR spectroscopy, differential scanning calorimetric (DSC), and thermogravimetric analysis (TGA) analysis. The polyimides with inherent viscosities in the range of 0.048–0.095 L/g showed excellent solubility in aprotic amide and organic solvents, such as N,N-dimethylacetamide, N-methyl-2-pyrrolidinone, dimethylformamide and acetone, chloroform, etc. DSC showed glass transition temperatures (T _g) in the range of 116–143 °C. These polymers showed excellent thermal stability up to 390 °C.     

Synthesis,characterization, and properties of novel aromatic polyamides containing phthalazinone moiety

A unsymmetrical and kink non-coplanar heterocyclic dicarboxylic acid monomer, 4-[4-(4-carboxy phenoxy)-naphthyl]-2-(4-carboxyphenyl)phthalazin-1-one (3) was successfully synthesized with high purity and high yields. A series of novel polyamides containing phthalazinone were prepared from the newly synthesized dicarboxylic acid with various aromatic diamines by means of the phosphorylation polycondensation reaction. Molecular weights of the obtained polyamides were evaluated viscometrically, and the inherent viscosities (η_inh) measured were in the range 0.54–0.69 dL/g. These polyamides were amorphous and readily soluble in many organic solvents, such as N-methyl-2-pyrrolidone, N,N-dimethylacetamide, N,N-dimetheylformamide, dimethyl sulfoxide, pyridine, and m-cresol etc., and they could easily be solution-cast into transparent, flexible films with good mechanical properties, with tensile strength ranging from 63.9 to 81.6 MPa and elongation at break from 7.2 to 11.4%. These polymers still kept good thermal stability with high-glass transition temperatures in the range of 283–338 °C, and the decomposition temperature in nitrogen for a 10% weight-loss temperatures in excess of 490 °C, and char yield at 800 °C in nitrogen ranged from 56 to 63%. Furthermore, the polyamides films were essentially colorless; their cut-off wavelengths were between 365 and 379 nm.     

Synthesis and Polymerization of Cationic bis(cyclopentadienyliron)arene Complexes Containing Arylazo Dyes

The synthesis of the title complexes was achieved via the reaction of -p-dichlorobenzene- -cyclopentadienyliron cations with 4,4′-bis(4-hydroxyphenyl)valeric acid to produce the diiron complexes which were then reacted with a number of arylazo dyes to give cationic bis(cyclopentadienyliron)arene complexes containing the arylazo dyes. These iron-containing monomers were subsequently polymerized via nucleophilic aromatic substitution using 1,8-octanedithiol, 4,4′-thiobisbenzenethiol, or bisphenol A to produce the desired coloured cationic organoiron polymers. The weight – average molecular weights were estimated to range from 11,800 to 31,600. UV–vis studies conducted in dimethylformamide (DMF) showed that the metallated polymers exhibited of 412–491 nm. Addition of HCl to the polymer solution caused a bathochromic shift into the range of 515–530 nm. Thermogravimetric analysis (TGA) revealed that the iron moieties were cleaved between 205 and 248 °C while the polyether/thioether backbone degraded between 380 and 613 °C. Differential scanning calorimetry (DSC) showed that the polymers exhibited glass transition temperatures (Tg) ranging from 106 to 184°C.This paper is dedicated to Professor Richard J. Puddephatt in recognition of his outstanding contribution to the field of metal-containing polymers.     

Hydrothermal Synthesis of Cd(II), Mn(II) and Ni(II) Coordination Polymers Derived from Benzopenone-2,4′-carboxylate and N-door Ligands

Three new coordination polymers [Cd(L)(4,4′-bipy)_0.5]_n (1), {[Mn(L)(bpp)]·H₂O}_n (2) and [Ni(L)(2,2′-bipy)(H₂O)₂]_n(3) [H₂L = Benzopenone-2,4′-dicarboxylic acid, 4,4′-bipy = 4,4′-bipy ridine, bpp = 1,3-di(4-pyridyl) propane and 2,2′-bipy = 2,2′-bipyridine] have been synthesized and structurally characterized by elemental analysis, IR and X-ray diffraction. Single-crystal X-ray analyses revealed that the H₂L ligand acts as a bridge, exhibiting three coordination modes to link metal ion: bidentate chelating, bis-monodentate, monodentate. Compound 1 has 3-connected metal–organic framework with the (6³) topology notation; Compounds 2 and 3 are one-dimensional chain structures. The luminescent properties for compound 1 was investigated.     

Syntheses and Crystal Structures of Two Inorganic–Organic Hybrid Frameworks Constructed from Pyridine-2,5-Dicarboxylic Acid

Two novel inorganic–organic hybrid frameworks of [Co(2,5-pydc)(4,4′-bipyo)_0.5(H₂O)₃ · 3H₂O] _n (1) and [Cu_1.5Gd(2,5-pydc)₃(2,2′-bipyo)(H₂O)₄ · 2H₂O] _n (2) (2,5-pydc = pyridine-2,5-dicarboxylic acid; 4,4′-bipyo = 4,4′-bipyridine-N,N′-dioxide; 2,2′-bipyo = 2,2′-bipyridine-N,N′-dioxide) were prepared. Both compounds have been characterized by the elemental analyses, IR spectra, TG analysis and the single crystal diffraction. The salient structural feature for both compounds 1 and 2 is that the 1D chain and the mononuclear fragment are connected by strong hydrogen bond interactions to form 2D structure.     

Heat stable and organosoluble polyimides containing laterally-attached phenoxy phenylene groups

In this research a diamine monomer containing two phenoxy phenylene lateral groups, 2,2′-bis[(p-phenoxy phenyl)]-4,4′-diaminodiphenyl ether (PPAPE) was used to prepare novel wholly aromatic polyimides by thermal or chemical two-step polycondensation reactions. Comonomers including pyromellitic dianhydride (PMDA), 4,4′-oxydiphthalic anhydride (ODPA), and 3,3′,4,4′-benzophenonetetracarboxylic dianhydride (BTDA) were used for the polyimidization reactions. A reference polyimide was also prepared by the reaction of 4,4′-diaminodiphenyl ether (DADPE) with pyromellitic dianhydride (PMDA). The limited viscosity numbers as well as [`(M)]<sub>n</sub> \overline{M}_n and [`(M)]_w \overline{M}_w values of the resulting polymers were determined. All PPAPE-resulted polyimides had excellent organosolubility in common polar solvents. A low crystallinity extent was only observed using their wide-angle X-ray diffractograms (WAXD). The prepared hinged polyimides could also be cast into transparent and flexible films. The glass transition temperatures of the resulting polyimides were determined by differential scanning calorimetry (DSC) analyses. The thermograms obtained from thermogravimetric analyses (TGA) showed that the phenoxy phenylene lateral groups attached to the macromolecular backbones had no substantial diminishing effect on the thermal stability of these structurally-modified polyimides.     

Synthesis and Characterization of ZnO Nanoparticles via Thermal Decomposition of Two Zinc(II) Supramolecular Compounds

A new nano-sized Zn(II) complex, [Zn(5,5′-dtbu-2,2′-bipy)Cl₂] _n (1) was synthesized and its structure determined by X-ray crystallography. The new nano-sized complex was prepared at oleic acid as a surfactant at 280 °C and characterized by scanning electron microscopy, elemental analyses and IR spectroscopy. The ZnO nano-particles were synthesized from thermolysis of nano-compound 1 at 600 °C and similar compound, [Zn(5,5′-dimethyl-2,2′-bipy)Cl₂] _n (2), at two different methods. SEM images show the average size of ZnO nano-particles are 78 and 50 nm for the compounds 1 and 2, respectively.     

Main-chain azo polyaramides with high thermal stability and liquid crystal properties

Two novel main-chain aromatic polyamides containing azobenzene were synthesized by polycondensation of trans-azobenzene-4,4′-dicarbonyl chloride with various aromatic diamines under low temperature. Their molecular structures were identified to be symmetric and regular by Fourier transform infrared spectroscopy, proton nuclear magnetic resonance spectroscopy and elemental analysis. Polymers exhibited not only high thermal stability, but also lyotropic liquid crystal (LC) phases in N,N-dimethylacetamide solution which is due to hydrogen bonding and an ordered rigid structure. The crystal behaviours of the polymers were studied with X-ray diffraction analysis, and the photochromism was investigated with an ultraviolet–visible spectrophotometer with 365 nm ultraviolet irradiation. An abnormal change of the crystal behavior and thermal stability of polymer was found to be related with molecular structure containing ether linkage. The azo polyaramides can be applied in fields of optical techniques and potential photochromics fibres spinning in wide temperature ranges     

Synthesis and characterization of polyamides and poly(amide-imide)s based on ether-sulfone-diamines

A series of polyamides and poly(amide-imide)s were prepared by the direct polycondensation of 4,4′-[sulfonylbis(1,4-phenyleneoxy)]dianiline or 4,4′-[sulfonylbis(2,6-dimethyl-1,4-phenyleneoxy)]dianiline with aromatic dicarboxylic acids and phthalimide unit-bearing dicarboxylic acids in a N-methyl-2-pyrrolidone (NMP) solution containing dissolved calcium chloride using triphenyl phosphite and pyridine as condensing agents. The inherent viscosities of the resulting polymers were above 0.45 dL/g and up to 1.70 dL/g. Except for the polyamides derived from terephthalic acid and 4,4′-biphenyldicarboxylic acid, all the other polyamides and all poly(amide-imide)s were readily soluble in polar organic solvents such as NMP, N, N-dimethylacetamide (DMAc), N,N-dimethylformamide (DMF), dimethyl sulfoxide (DMSO), and m-cresol, and afforded transparent and tough films by solution-casting. Most of the polymers showed distinct glass transition on their differential scanning calorimetry (DSC) traces and their glass transition temperatures (T_g) stayed between 140–264 °C. The methyl-substituted polymers showed higher T_gs than the corresponding unsubstituted counterparts. The results of the thermogravimetry analysis (TGA) revealed that all the methyl-substituted polymers showed lower initial decomposition temperatures than the unsubstituted ones.