New polymer syntheses. CXI. Aliphatic polyesters by the ring‐opening polycondensation of glutaric anhydride with ethylene or trimethylene carbonate

Several polycondensations of ethylene carbonate with succinic anhydride or glutaric anhydride (GA) were conducted in bulk. Low molar mass polyesters were obtained with pyridine‐type catalysts and GA. Analogous polycondensations of trimethylene carbonate (TMC) and GA were successful when quinoline, 4‐(N,N‐dimethylamino)pyridine, or BF₃ · OEt₂ was used as a catalyst. Matrix‐assisted laser desorption/ionization time‐of‐flight mass spectra revealed the formation of cyclic oligoesters and polyesters by backbiting degradation. Monomer mixtures containing an excess of TMC yielded copoly(ester carbonate)s with number‐average molecular weights up to 16,000 Da. Analogous copoly(ester carbonate)s were obtained from TMC and 3,3′‐tetramethylene glutaric anhydride. Furthermore, combined polycondensation/ring‐opening polymerization reactions of TMC and GA with L ‐lactide or ?‐caprolactone were studied. All copolymers were characterized by viscosity measurements and by IR, ¹H, and ¹³C NMR spectroscopy. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 4357–4367, 2002     

Investigation of catalyst‐transfer condensation polymerization for the synthesis of n‐type π‐conjugated polymer,poly(2‐dioxaalkylpyridine‐3,6‐diyl)

Kumada‐Tamao coupling polymerization of 6‐bromo‐3‐chloromagnesio‐2‐(3‐(2‐methoxyethoxy)propyl)pyridine 1 with a Ni catalyst and Suzuki‐Miyaura coupling polymerization of boronic ester monomer 2 , which has the same substituted pyridine structure, with ^tBu₃PPd(o‐tolyl)Br were investigated for the synthesis of a well‐defined n‐type π‐conjugated polymer. We first carried out a model reaction of 2,5‐dibromopyridine with 0.5 equivalent of phenylmagnesium chloride in the presence of Ni(dppp)Cl₂ and then observed exclusive formation of 2,5‐diphenylpyridine, indicating that successive coupling reaction took place via intramolecular transfer of Ni(0) catalyst on the pyridine ring. Then, we examined the Kumada‐Tamao polymerization of 1 and found that it proceeded homogeneously to afford soluble, regioregular head‐to‐tail poly(pyridine‐2,5‐diyl), poly(3‐(2‐(2‐(methoxyethoxy)propyl)pyridine) (PMEPPy). However, the molecular weight distribution of the polymers obtained with several Ni and Pd catalysts was very broad, and the matrix‐assisted laser desorption ionization time‐of‐flight mass spectra showed that the polymer had Br/Br and Br/H end groups, implying that the catalyst‐transfer polymerization is accompanied with disproportionation. Suzuki‐Miyaura polymerization of 2 with ^tBu₃PPd(o‐tolyl)Br also afforded PMEPPy with a broad molecular weight distribution, and the tolyl/tolyl‐ended polymer was a major product, again indicating the occurrence of disproportionation. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012     

Synthesis of some alkylaminothiophene derivatives from 3,4-dibromothiophene and their theoretical calculations

In this study, the copper catalyzed amination reactions of 3,4-dibromothiophene with some primary, cyclic and acyclic secondary amines were investigated to prepare novel electron rich-thiophenes which are expected to be used as novel N-containing donor type monomer candidates for conductive polymers. In order to obtain better yields, this S_NAr type amination reaction was optimized by studying the reaction conditions, such as the copper catalyst, the type of copper source, the presence of a base and the type of the solvent on the model reaction between 3,4-dibromothiophene and n-butylamine. A variety of 3,4-(N,N′-dialkylamino)thiophenes and 3-(N-alkylamino)thiophenes were synthesized in moderate yields under the optimized reaction conditions. In addition, two new heterocyclothiophene derivatives were successfully prepared from the cyclization reaction of 3,4-bis(N-butylamino)thiophene. The characterization of the isolated alkylaminothiophenes was performed by FTIR, ¹H and ¹³C NMR, GCMS and elemental analysis. The theoretical calculations for all alkylaminothiophenes were executed by using the DFT/B3LYP/6-311+G(2d,p) approach.     

Intramolecular Catalyst Transfer on a Variety of Functional Groups between Benzene Rings in a Suzuki–Miyaura Coupling Reaction

Suzuki–Miyaura coupling reaction of BrC₆H₄-X-C₆H₄Br 1 (X=CH₂, CO, N-Bu, O, S, SO, and SO₂) with arylboronic acid 2 was investigated in the presence of tBu₃PPd precatalyst and CsF/[18]crown-6 as a base to establish whether or not the Pd catalyst can undergo catalyst transfer on these functional groups. In the reaction of 1 (X=CH₂, CO, N-Bu, O, and SO₂) with 2 , aryl-disubstituted product 3 (Ar-C₆H₄-X-C₆H₄-Ar) was exclusively obtained, indicating that the Pd catalyst undergoes catalyst transfer on these functional groups. On the other hand, the reaction of 1 e (X=S) and 1 f (X=SO) with 2 afforded only aryl-monosubstituted product 4 (Ar-C₆H₄-X-C₆H₄-Br) and a mixture of 3 and 4 , respectively, indicating that S and SO interfere with intramolecular catalyst transfer. Furthermore, we found that Suzuki–Miyaura polycondensation of 1 (X=CH₂, CO, N-Bu, O, and SO₂) and phenylenediboronic acid 5 in the presence of tBu₃PPd precatalyst afforded high-molecular-weight polymer even when excess 1 was used. The polymers obtained from 1 (X=CH₂, N-Bu, and O) and 5 turned out to be cyclic.     

Effect of solvent on the reactivity of functional groups in polycondensation reactions

The effect of solvent on solution or interfacial polycondensations was investigated in terms of selectivity and control of functional groups such as amine or hydroxyl groups toward polycondensation reactions. Solution polycondensation of a mixture of resorcinol (RL) and m-xylyenediamine (m-XD) with isophthaloyl chloride was affected by solvents to such extent as to change the course of the polycondensation reaction, and hexamethylenephosphoramide (HMPA) caused the formation of amide-rich polymer, while tetrahydrofuran (THF) was a solvent favoring formation of a polyamide ester with a regular structure. Polycondensation of 3,3′-dihydroxybenzidine (DHB) with isophthaloyl chloride yielded exclusively a linear polyamide in HMPA solution, while with aldehyde as a solvent polyester was obtained owing to the preservation of the amine group. Thus, it was found that the course of polycondensation reactions of monomers having different functional groups could be controlled by selection of a suitable solvent.     

Studies on reactions of the N-phosphonium salts of pyridines. XIV. Wholly aromatic polyamides by the direct polycondensation reaction by using phosphites in the presence of metal salts

Poly-p-benzamide of high molecular weight (η_inh = ～ in H₂SO₄) was obtained by the direct polycondensation reaction of p-aminobenzoic acid (p-ABA) by means of diphenyl and triaryl phosphites in N-methylpyrrolidone (NMP)-pyridine solution containing lithium and calcium chlorides. Molecular weight of polymer varied with the amount of these salts, showing maximum values at the concentration of about 4 wt-% of LiCl or about 8 wt-% of CaCl₂ in the reaction mixture. The reaction temperature at around 80°C gave a polymer of the highest viscosity. The polycondensation reaction was also affected by monomer concentration, solvents, and tertiary amines like pyridine. Similarly, aromatic polyamides with high molecular weight (η_inh values up to 1.34 in H₂SO₄) were prepared from isophthalic acid and aromatic diamines, whereas terephthalic acid gave only low-viscosity polymers.     

Synthesis and characterization of tribenzyltin heteroaromatic carboxylates and crystal structure of tribenzyltin 4‐pyridinecarboxylate

Reaction of tribenzyltin chloride with 2‐furan‐, 2‐(2‐furanyl)‐vinyl‐, 2‐(5‐t‐butyl) furan‐, 2‐thiophene‐, 2‐pyridine‐, 3‐pyridine‐, 4‐pyridine‐, 3(1H)‐indole‐, 3(1H)‐indolylmethyl‐or 3‐[3(1H)‐indolyl]propyl‐carboxylate in 1:1 stoichiometry yielded tribenzyltin heteroaromatic carboxylate (PhCH₂)₃‐SnO₂CR. All compounds were characterized by elemental analysis, IR, ′H NMR and MS. The crystal structure of tribenzyltin 4‐pyridinecarboxylate was determined by single crystal X‐ray diffraction. In the crystal of tribenzyltin 4‐pyridinecarboxylate, the tin atoms are five‐coordinated in a trigonal bipyramidal structure with a linear polymer containing Sn–‐O bond with length of 0. 2142(2) nm and Sn–‐N bond with length of 0.2563(4) nm.     

Direct sulfhydrolysis of cyclic AMP: A one-step synthesis of the cyclic ribonucleotide of 6-mercaptopurine

Treatment of adenosine cyclic 3′,5′-phosphate with liquid H₂S in aqueous pyridine provided a convenient, one-step synthesis of 9-β-D-ribofuranosylpurine-6(1H) thione cyclic 3′,5′-phosphate.     

An Alternative Synthysis of Thieno[3,4-b]Thiophene

Thieno[3,4-b]thiophene has been obtained in greater than 50% yield starting from 3,4-dibromothiophene by a sequence of Pd^II-Cu^I-catalysed cross-coupling with trimethylsilylacetylene, bromine-lithium exchange, thiolation with elemental sulfur and ring-closure in aqueous medium.     

High-molecular-weight poly(p-phenyleneterephthalamide) by the direct polycondensation reaction with triphenyl phosphite

Poly(p-phenyleneterephthalamide) of high molecular weight was obtained when the polycondensation of terephthalic acid and p-phenylenediamine was carried out in N-methylpyrrolidone (NMP) that contained dissolved CaCl₂ and LiCl in the presence of pyridine. The molecular weight of the polymer obtained varied with the amount of pyridine relative to the metal salts and with the molar ratios of CaCl₂ to LiCl, the maximum η_inh value of 4.5 being obtained under the conditions Py/(CaCl₂ + LiCl) ≈ 2.5 (mol/mol), CaCl₂/LiCl ≈ 1.2 (mol/mol), and LiCl + CaCl₂ ≈ 4 g. Among the solvents tested, NMP was significantly effective for the reaction. Polycondensations of several combinations of other dicarboxylic acids and diamines were carried out with limited success.     

Chain-growth polycondensation of potassium 3-cyano-4-fluorophenolate derivatives for well-defined poly(arylene ether)s

Polycondensation normally proceeds in a step-growth reaction manner to give polymers with a wide range of molecular weights. However, the polycondensation of potassium 2-alkyl-5-cyano-4-fluorophenolate ( 1 ) proceeded at 150°C in a chain polymerization manner from initiator, 4-fluoro-4′-trifluoromethyl benzophenone ( 2 ), to give aromatic polyethers having controlled molecular weights and low polydispersities (M_w/M_n ⩽ 1.2). The resulting polycondensation of 1 had all of the characteristics of living polymerization and displayed a linear correlation between molecular weight and monomer conversion, maintaining low polydispersities. Sulfolane was a better solvent for chain-growth polycondensation of 1 than other aprotic solvents. The polyether from 1 with a low polydispersity showed higher crystallinity than that with a broad molecular weight distribution, obtained by the conventional polycondensation of 1 without 2 .     

Direct polycondensation of aromatic dicarboxylic acids and bisphenols with tosyl chloride and N,N-dimethylformamide in pyridine

A Vilsmeier adduct derived from arylsulfonyl chlorides and DMF in pyridine was successfully used as a new condensating agent for the synthesis of aromatic polyesters by the direct polycondensation of aromatic dicarboxylic acids and bisphenols and also of hydroxybenzoic acids. Polymers of high molecular weights (M?_w = 78,000) with relatively narrow molecular weight distribution (M?_w/M?_n ≈ 3.0) were prepared by reacting aromatic dicarboxylic acids with the adduct in pyridine, followed by addition of bisphenols. The polycondensation was significantly affected by the amount of DMF, the nature of the arylsulfonyl chlorides, the conditions of initial reaction of the acids with the adduct, and the rate of reaction with bisphenols. The process was adaptable to the direct polycondensation of hydroxybenzoic acids, affording polymers of high molecular weight (η_inh = 1.73).     

Enhancement of the Photovoltaic Performance of CH3NH3PbI3 Perovskite Solar Cells through a Dichlorobenzene‐Functionalized Hole‐Transporting Material

A dichlorobenzene‐functionalized hole‐transporting material (HTM) is developed for a CH₃NH₃PbI₃‐based perovskite solar cell. Notwithstanding the similarity of the frontier molecular orbital energy levels, optical properties, and hole mobility between the functionalized HTM [a polymer composed of 2′‐butyloctyl‐4,6‐dibromo‐3‐fluorothieno[3,4‐b]thiophene‐2‐carboxylate (TT‐BO), 3′,4′‐dichlorobenzyl‐4,6‐dibromo‐3‐fluorothieno[3,4‐b]thiophene‐2‐carboxylate (TT‐DCB), and 2,6‐bis(trimethyltin)‐4,8‐bis(2‐ethylhexyloxy)benzo[1,2‐b:4,5‐b′]dithiophene (BDT‐EH), denoted PTB‐DCB21] and the nonfunctionalized polymer [a polymer composed of thieno[3,4‐b]thiophene (TT) and benzo[1,2‐b:4,5‐b′]dithiophene (BDT), denoted PTB‐BO], a higher power conversion efficiency for PTB‐DCB21 (8.7 %) than that for PTB‐BO (7.4 %) is achieved because of a higher photocurrent and voltage. The high efficiency is even obtained without including additives, such as lithium bis(trifluoromethanesulfonyl)imide and/or 4‐tert‐butylpyridine, that are commonly used to improve the conductivity of the HTM. Transient photocurrent–voltage studies show that the PTB‐DCB21‐based device exhibits faster electron transport and slower charge recombination; this might be related to better interfacial contact through intermolecular chemical interactions between the perovskite and the 3,4‐dichlorobenzyl group in PTB‐DCB21.     

Intramolecular donor–acceptor copolymers containing side‐chain‐tethered perylenebis(dicarboximide) moieties for panchromatic solar cells

A series of side‐chain‐tethered copolymers containing the N‐(2‐ethylhexyl)‐N′‐(thiophene‐3‐yl)‐3,4:9,10‐perylenebis(dicarboximide) (thiophene‐PDI) moieties and 4,4‐diethylhexyl‐cyclopenta[2,1‐b:3,4‐b′]dithiophene unit were synthesized via Grignard metathesis polymerizations. With the incorporation of pendent perylenebis(dicarboximide) (PDI) moieties as acceptor side chains and thiophene as the donor backbone, the copolymers exhibited the intramolecular donor–acceptor characteristic and displayed a panchromatic absorption ranging from 290 to 1100 nm and ideal bandgaps of 1.49 to 1.52 eV. Due to the coplanarity of PDI moieties, the charge separation and transfer process were more effective and enhanced after photoexcitation. When increased the weight ratio of PC₆₁BM:polymer to 3, the J_sc could be raised significantly. The value of bandgap decreased slightly, and both V_oc and J_sc showed an upward trend with the increase of molar ratio of thiophene‐PDI unit from 50% (the copolymer P11) to 75% (the copolymer P13). The polymer/PC₆₁BM devices have shown a significant improvement from 0.45 to 1.66% with a judicious modulation. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52, 1978–1988     

Direct polycondensation of hydroxybenzoic acids with thionyl chloride in pyridine

The reaction promoted by thionyl chloride and pyridine could selectively activate carboxyl groups of hydroxybenzoic acids to give polyesters of high inherent viscosities up to 3.8. Favorable conditions were studied in terms of the temperatures for the initial reaction with the acids and subsequent aging at room temperature. Copolymers of several combinations of hydroxybenzoic acids with high molecular weights were obtained in quantitative yield by carrying out the polycondensation at 80°C for 3 h. The reaction could also produce high molecular polyesters in a simpler process without the initial activation of dicarboxylic acids by adding a mixture of these monomers to the condensing agent, and a tough film- and fiberforming polymer was obtained from 4,4′-dihydroxyphenylsulfone of low nucleophilicity whose polymer of high molecular weight is difficult to obtain. The process was also successfully applied to the direct copolycondensations of hydroxybenzoic acids, aromatic dicarboxylic acids, and bisphenols to produce polyesters of η_inh up to 5.6.     

Preparation of polyaryl esters by a new direct polycondensation reaction with arylsulfonyl chlorides in pyridine

Arylsulfonyl chlorides were successfully used as a new condensing agent for the synthesis of polyaryl esters by the direct polycondensation of aromatic dicarboxylic acids and bisphenols. High-molecular-weight polymers (M_w = 84,000) were prepared by reacting dicarboxylic acids with the sulfonyl chlorides in pyridine in the presence of LiCI, followed by treating with a pyridine solution of bisphenols. The polycondensation was significantly affected by factors, such as, the kind of arylsulfonyl chlorides, its amount, the conditions of initial reaction of the acids with the sulfonyl chlorides, the amounts of LiCI added, and dropwise addition of bisphenols.     

以2-(1-吡唑基甲基)吡啶类化合物为配体的羰基钼、钨衍生物的合成及结构

合成了2-[1-(3-叔丁基)吡唑基甲基]吡啶(CH2(Py)(3-ButPz)),并研究了羰基钼(钨)与该配体及其类似物2-(1-吡唑基甲基)吡啶(CH2(Py)(Pz))和2-[1-(3,5-二甲基)吡唑基甲基]吡啶(CH2(Py)(3,5-Me2Pz))的反应,合成了6个含双齿螯合的2-(1-吡唑基甲基)吡啶类配体的四羰基金属衍生物CH2(Py)(3-ButPz)M(CO)4,CH2(Py)(Pz)M(CO)4和CH2(Py)(3,5-Me2Pz)M(CO)4(M=Mo或W)。当用SnCl4处理CH2(Py)(3,5-Me2Pz)M(CO)4时,Sn-Cl键对金属中心发生氧化加成得到2个杂双核金属有机化合物CH2(Py)(3,5-Me2Pz)M(CO)3(Cl)SnCl3。所有新化合物均通过了红外和核磁的表征,CH2(Py)(3-ButPz)W(CO)4和CH2(Py)(3,5-Me2Pz)W(CO)3(Cl)SnCl3的结构还得到了X-射线单晶衍射的确证。用循环伏安法测定了四羰基金属衍生物的电化学性质。     

Chemoselective polyesterification by direct polycondensation

A convenient method for the synthesis of polyester‐containing amino substitutes on the aromatic rings of the backbone has been developed. This polyester was prepared by chemoselective polyesterification of isophthalic acid with bisphenol having an amino group in the presence of the condensing agent diphenyl(2,3‐dihydro‐2‐thioxo‐3‐benzoxazolyl)phosphonate ( 1 ) and 1,5‐diazabicyclo[4,3,0]‐5‐nonene as a base. The model reactions were carried out in detail to elucidate appropriate conditions of chemoselective polyesterification. Direct polycondensation of isopthalic acid with 4,4′‐[1‐(4‐aminophenyl)ethylidene]bisphenol proceeded smoothly under mild conditions and produced the desired polyester with a number average molecular weight of 11,000 and M_w/M_n of 2.22. The polymer obtained was characterized by IR, ¹H, and ¹³C NMR spectroscopies. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 39: 78–85, 2001     

Direct polycondensation in ionic liquids

Ionic liquids (ILs) are subject to an enormous research effort due to their unique properties, such as non-volatility, high solution and reactivity ability, etc. For the first time ILs have been used as a solvent for preparing polymers via direct polycondensation. The influence of IL's nature and reaction parameters upon the polymer formulation has been investigated. It is shown that direct polycondensation is successfully proceeded in ILs and triphenyl phosphite (condensing agent) without any additional extra components, such as LiCl and pyridine, using in similar reactions in ordinary molecular solvents. Various polyamides (η_inh=0.11-1.10 dl/g), polyamide imides (η_inh=0.48-1.41 dl/g), -hydrazides (η_inh=0.56-0.60 dl/g) and polyhydrazides (η_inh=0.71-1.32 dl/g) have been obtained in quantitative yield and high molecular weight.     

Nitration of dithieno[3,4-b:3′,2′-d]pyridine and dithieno[2,3-b:3′,2′-d]pyridine

The nitration of dithieno[3,4-b:3′,2′-d]pyridine ( 2 ) and dithieno[2,3-b:3′,2′-d]pyridine ( 3 ) has been studied. Nitration of 2 occurred in both positions of the c-fused thiophene ring, while 3 was predominantly substituted in the 2-position. The structures of the nitro derivatives were proven by extensive use of ¹H and ¹³C nmr spectroscopy.