Synthesis and properties of poly(ether imide)s derived from 2,6-bis(3,4-dicarboxyphenoxy)naphthalene dianhydride and aromatic diamines

A new naphthalene unit-containing bis(ether anhydride), 2,6-bis(3,4-dicarboxyphenoxy)naphthalene dianhydride, was synthesized in three steps starting from the nucleophilic nitrodisplacement reaction of 2,6-dihydroxynaphthalene and 4-nitrophthalonitrile in N,N-dimethylformamide (DMF) solution in the presence of potassium carbonate, followed by alkaline hydrolysis of the intermediate bis(ether dinitrile) and subsequent dehydration of the resulting bis(ether diacid). High-molar-mass aromatic poly(ether imide)s were prepared using a conventional two-step polymerization process from the bis(ether anhydride) and various aromatic diamines. The intermediate poly(ether amic acid)s had inherent viscosities of 0.65–2.03 dL/g. The films of poly(ether imide)s derived from two rigid diamines, i.e. p-phenylenediamine and benzidine, crystallized during the thermal imidization process. The other poly(ether imide)s belonged to amorphous materials and could be fabricated into transparent, flexible, and tough films. These aromatic poly(ether imide) films had yield strengths of 104–131 MPa, tensile strengths of 102–153 MPa, elongation to break of 8–87%, and initial moduli of 1.6–3.2 GPa. The glass transition temperatures (T_g's) of poly(ether imide)s were recorded in the range of 220–277°C depending on the nature of the diamine moiety. All polymers were stable up to 500°C, with 10% weight loss being recorded above 550°C in both air and nitrogen atmospheres. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 1657–1665, 1998     

Comparison of the electronic structure of different perylene‐based dye‐aggregates

Aggregates of functionalized polycyclic aromatic molecules like perylene derivatives differ in important optoelectronic properties such as absorption and emission spectra or exciton diffusion lengths. Although those differences are well known, it is not fully understood if they are caused by variations in the geometrical orientation of the molecules within the aggregates, variations in the electronic structures of the dye aggregates or interplay of both. As this knowledge is of interest for the development of materials with optimized functionalities, we investigate this question by comparing the electronic structures of dimer systems of representative perylene‐based chromophores. The study comprises dimers of perylene, 3,4,9,10‐perylene tetracarboxylic acid bisimide (PBI), 3,4,9,10‐perylene tetracarboxylic acid dianhydride (PTCDA), and diindeno perylene (DIP). Potential energy curves (PECs) and characters of those electronic states are investigated which determine the optoelectronic properties. The computations use the spin‐component‐scaled approximate coupled‐cluster second‐order method (SCS‐CC2), which describes electronic states of predominately neutral excited (NE) and charge transfer (CT) character equally well. Our results show that the characters of the excited states change significantly with the intermolecular orientation and often represent significant mixtures of NE and CT characters. However, PECs and electronic structures of the investigated perylene derivatives are almost independent of the substitution patterns of the perylene core indicating that the observed differences in the optoelectronic properties mainly result from the geometrical structure of the dye aggregate. It also hints at the fact that optical properties can be computed from less‐substituted model compounds if a proper aggregate geometry is chosen. © 2012 Wiley Periodicals, Inc.     

A novel positively thermo-sensitive hydrogel based on ethylenediaminetetraacetic dianhydride and piperazine: Design, synthesis and characterization

A new positively thermo-sensitive hydrogel was designed and synthesized by a condensation polymerization reaction of ethylenediaminetetraacetic dianhydride（EDTAD） and piperazine（PA） to give poly（ethylenediaminetetraacetic dianhydride-copiperazine） （PEP）.The obtained polymers’ structure was characterized by FTIR and ¹³C NMR.The backbone of the polymer linked by amide bond and abundant of carboxyl groups as pendant group could form strong intermolecular and intramolecular hydrogen bond at lower temperature and dissociate at higher temperature,resulting in the polymer with thermo-sensitivity.The aqueous solution of PEP at lower temperature（<20℃） showed micro-gel formation and transformed to transparent solution at higher temperature（>40℃）.Transition temperature shifted to higher value with the increasing of concentration.The hydrogel exhibited reversible phase transition and the transmittance change was not weakened by multiple temperature changes.     

溴代1,4,5,8-萘四甲酸酐的选择性合成

在常压下, 以溴化钠和发烟硫酸(含质量分数为40%的SO₃)为溴化试剂, 通过控制反应温度、 反应时间和溴化钠的投料比选择性地合成了2-溴-1,4,5,8-萘四甲酸酐和2,6-二溴-1,4,5,8-萘四甲酸酐. 本研究提供了一种合成溴代1,4,5,8-萘四甲酸酐衍生物的新方法.     

HETEROAROMATIC POLYMERS - HIGH TEMPERATURE POLYPYRROLONES DERIVED FROM 2,6-BIS(3′,4′-DIAMINOPHENYL)-4-BIPHENYLPYRIDINE AND VARIOUS AROMATIC DIANHYDRIDES

A new type of aromatic tetraamine containing biphenyl moiety in the side chain was synthesized via a modified Chichibabin's reaction. 3-Nitro-4-acetamidoacetophenone was reacted with 4-phenyl benzaldehyde in the presence of ammonium acetate to obtain 2,6-bis(3′,4′-diaminophenyl)-4-biphenyl pyridine (DPPA). A series of polypyrrolones (PPys)were prepared using tetraamine and various aromatic dianhydrides via a two-step cyclization procedure. All the PPys show excellent high temperature stabilities with the initial decomposition temperatures of 530-549℃ and residual weight ratio of 49%-80% at 750℃ in nitrogen. The polymers exhibit no apparent glass transition temperatures (Tgs) except PPy-1(Tg = 327℃), which is derived from tetraamine DPPA and 2,2-bis[4-(3′,4′-dicarboxyphenoxy)-phenyl]propane dianhydride (BPADA). In addition, the polymers have acceptable mechanical properties with the tensile strength of 65-94 MPa. The PPy films show excellent hydrolysis-resistance in alkaline aqueous medium and could maintain most of the properties even after boiling in 10% aqueous sodium hydroxide solution for a week.     

联萘衍生物作为手性固定相在高效液相色谱中的应用

光学活性的联萘衍生物以其独特的立体化学性质作为优异的C2轴手性诱导源,已被广泛地应用到不对称催化反应和手性识别中。综述了联萘衍生物作为手性固定相在高效液相色谱中的应用。引用文献54篇。     

(S, R)联萘酚磷酰胺包合物的合成及晶体结构

本文合成了主体分子(S, R)-1, 1'-联萘-2, 2'-二羟基磷酰(N-α-苯乙基)胺及8种包合物, 经熔点、结晶形状及元素分析确定了它们的组成; 并经过X-射线衍射分析确定了其乙醇包合物的单晶结构, 晶体属单斜晶系, 空间群P2~1,a=0.9365(1)nm, b=1.2825(7)nm, c=1.1640(3)nm, β=111.71°, Z=2,R=0.0469。其中主体分子形成层状结构, 客体分子处于相邻的层间。     

Syntheses and properties of organosoluble poly(ether imide)s from 1,1‐bis[4‐(3,4‐dicarboxyphenoxy)phenyl]cyclohexane dianhydride and aromatic diamines

A bis(ether anhydride) monomer, 1,1‐bis[4‐(3,4‐dicarboxyphenoxy)phenyl]cyclohexane dianhydride ( IV‐A ), was synthesized from the nitro displacement of 4‐nitrophthalodinitrile by the phenoxide ion of 1,1‐bis(4‐hydroxyphenyl)cyclohexane ( I‐A ), followed by alkaline hydrolysis of the intermediate bis(ether dinitrile) and dehydration of the resulting bis(ether acid). A novel series of organosoluble poly(ether imide)s ( VI _a–i )(PEIs) bearing cyclohexylidene cardo groups was prepared from the bis(ether anhydride) IV‐A with various aromatic diamines V _a–i via a conventional two‐stage process. The PEIs had inherent viscosities in the range of 0.48–1.02 dL/g and afforded flexible and tough films by solution‐casting because of their good solubilities in organic solvents. Most PEIs showed yield points in the range of 89–102 MPa at stress‐strain curves and had tensile strengths of 78–103 MPa, elongations at breaks of 8–62%, and initial moduli of 1.8–2.2 GPa. The glass‐transition temperatures (T_g's) of these PEIs were recorded between 200–234 °C. Decomposition temperatures of 10% weight loss all occurred above 490 °C in both air and nitrogen atmospheres, and their residues were more than 43% at 800 °C in nitrogen atmosphere. The cyclohexane cardo‐based PEIs exhibited relatively higher T_g's, better solubilities in organic solvents, and better tensile properties as compared with the corresponding Ultem® PEI system. © 2001 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 39: 788–799, 2001     

Synthesis of novel poly(thioether‐naphthalimide)s that utilize hydrazine as the diamine

A series of bis(4‐thio‐1,8‐naphthalic anhydride)s and the corresponding bis(N‐amino naphthalimide) derivatives were synthesized from readily available compounds in high yield. A series of novel poly(thioether‐naphthalimide)s, which utilized hydrazine as the diamine, were synthesized by a one‐step polymerization reaction in m‐cresol. Poly(thioether‐naphthalimide)s with inherent viscosities of 0.57–1.73 dL/g were obtained. The polymers were soluble in CHCl₃ and were determined to have high molecular weights by means of gel permeation chromatographic analysis. They were soluble in m‐cresol and could be cast into tough films from m‐cresol solution. The glass‐transition temperature (T_g) values of the polyimides ranged from 320 to 353 °C. Polyimides from the bisphenol dianhydride, derived from 9,9‐bis(4‐hydroxyphenyl)fluorene, did not show a clear transition in the DSC analysis. Degradation temperatures for 5% weight loss all occurred above 430 °C in nitrogen. The series of monomers were successfully copolymerized with each other. Monomers 6a and 7a , containing the bisphenol A moiety, could also be copolymerized with perylenetetracarboxylic dianhydride. These copolymers had high T_g's and were thermally stable. The UV–vis absorption properties of the polymers were also examined. © 2001 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 39: 1040–1050, 2001     

Synthesis of Chiral Crownophanes Having Two Phenolic Groups via Tandem Claisen Rearrangement and Their Chiral Recognition

Asymmetric crownophanes having a chiral binaphthyl unit and two phenolic hydroxyl groups were thermally synthesized from the corresponding macrocyclic ethers via tandem Claisen rearrangement. Circular dichroism (CD) spectroscopic studies and HPLC experiments confirmed that little racemization of these crownophanes occurred during the thermal rearrangement. The association constants for the interaction of the chiral crownophanes with the enantiomers of phenylethylamine, phenylglycinol, and phenylalaninol were determined by a ¹H NMR titration method in CD₂Cl₂. As a result, the 27 membered crownophane has some chiral recognition for phenylglycinol.