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The title complex [Cd(IPA)L(H2O)]n(1,H2IPA = isophthalic acid,L = 1,4-bis(pyra-zole-1-ylmethyl)benzene) has been hydrothermally synthesized,and characterized by elemental analyses,IR spectroscopy,TGA and X-ray single-crystal diffraction.It crystallizes in the triclinic system,space group P1 with a = 9.3060(6),b = 10.2374(7),c = 11.9706(8) ,α = 73.804(6),β = 77.883(5),γ = 85.942(5)°,V = 1070.7(1) 3,Z = 2,C22H20CdN4O5,Mr = 532.82,Dc = 1.653 g/cm3,μ = 1.062 mm-1,λ(MoKα) = 0.71073 ,F(000) = 536,R = 0.0392 and wR = 0.0640 for 3751 observed reflections with I > 2σ(I).Crystal structure analysis showed that complex 1 has a 1D double chain structure,which is assembled together through strong O-H...O hydrogen bonding interactions between coordinated water molecules and carboxylate groups of isophthalate to form a 2D supramolecular network.In addition,the solid-state fluorescent spectrum of 1 exhibits strong emission at 364 nm. 相似文献
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Two new complexes, {[Co(INAIP) · H2O] · 2H2O}n ( 1 ), and {[Cu(INAIP)] · H2O}n ( 2 ) [H2INAIP = 5‐(isonicotinamido)isophthalic acid] were synthesized under hydrothermal conditions, and characterized by single‐crystal X‐ray structure determination, thermogravimetric analysis, X‐ray powder diffraction, and magnetic studies. In complex 1 both CoII atoms and INAIP2– ligands act as four‐connected node, whereas in 2 both CuII atoms and INAIP2– ligands act as three‐connected node. 相似文献
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Darwin P. R. Kint Antxon Martínez De Ilarduya Sebastin Muoz‐Guerra 《Journal of Polymer Science.Polymer Physics》2001,39(13):1553-1564
The microstructure and crystallization behavior of a set of poly(ethylene terephthalate‐co‐5‐nitroisophthalate) copolymers (PETNI) containing 5‐nitroisophthalic units in the 10–50 mol % range were examined and compared to those of poly(ethylene terephthalate) (PET) and poly(ethylene terephthalate‐co‐isophthalate) (PETI) copolymers. A 13C NMR analysis of PETNI copolymers in a trifluoroacetic acid solution indicates that they are random copolymers with average sequence lengths in accordance with ideal polycondensation statistics. Differential scanning calorimetry (DSC) studies show that PETNI containing 5‐nitroisophthalic units up to 20 mol % are able to crystallize and that crystallization takes place in these copolymers at much slower rates than in PET. Wide‐angle X‐ray diffraction from powder and fibers reveals that crystallizable PETNI adopts the same triclinic crystal structure as PET, with the nitroisophthalate units being excluded from crystallites. Fourier transform infrared in combination with cross‐polarization/magic‐angle spinning 13C NMR spectroscopy demonstrates the occurrence of a gauche–trans conversion encompassing the crystallization process. A correlation between DSC and spectroscopic data leads us to conclude that the content of trans conformer in the noncrystallized phase of PETNI is higher than in both PET and PETI copolymers and suggests that secondary crystallization in the homopolymer must proceed by a mechanism different than that in copolymers. © 2001 John Wiley & Sons, Inc. J Polym Sci Part B: Polym Phys 39: 1553–1564, 2001 相似文献
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Darwin P. R. Kint Antxon Martínez de Ilarduya Abdelilah Alla Sebastin Muoz‐Guerra 《Journal of polymer science. Part A, Polymer chemistry》2003,41(1):124-134
Poly(ethylene terephthalate‐co‐isophthalate‐co‐5‐tert‐butylisophthalate) (PETItBI) terpolymers were investigated with reference to poly(ethylene terephthalate) (PET) homopolymer and poly(ethylene terephthalate‐co‐isophthalate) (PETI) copolymers. Three series of PETItBI terpolyesters, characterized by terephthalate contents of 90, 80, and 60 mol %, respectively, with different isophthalate/5‐tert‐butylisophthalate molar ratios, were prepared from ethylene glycol and mixtures of dimethyl terephthalate, dimethyl isophthalate, and 5‐tert‐butylisophthalic acid. The composition of the terpolymers and the composition of the feed agreed. All terpolymers had a random microstructure and number‐average molecular weights ranging from 10,000 to 20,000. The PETItBI terpolyesters displayed a higher glass‐transition temperature and a lower melting temperature than the PETI copolymers having the same content of terephthalic units. Thermal stability appeared essentially unchanged upon the incorporation of the 5‐tert‐butylisophthalic units. The PETItBIs were crystalline for terephthalate contents higher than 80 mol %, and they crystallized at lower rates than PETI. The crystal structure of the crystalline terpolymers was the same as that of PET with the 1,3‐phenylene units being excluded from the crystalline phase. Incorporation of isophthalate comonomers barely affected the tensile modulus and strength of PET, but the brittleness of the terpolymers decreased for higher contents in 5‐tert‐butylisophthalic units. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 124–134, 2003 相似文献
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Benjamin S. Hsiao Kenncorwin H. Gardner Stephen Z. D. Cheng 《Journal of Polymer Science.Polymer Physics》1994,32(16):2585-2594
In a previous study, we have investigated the structure, crystallization, and morphology of poly(aryl ether ketone ketone), PEKK, copolymers prepared from diphenyl ether (DPE), terephthalic acid (T), and isophthalic acid (I) with T/I ratios from 100/0 to 50/50. These materials were considered as having -DPE-T-DPE-T- (TT) and/or -DPE-T-DPE-I- (TI) “phthalate diads.” In this work, we continue the study of this copolymer series with six different T/I ratios (40/60, 30/70, 20/80, 15/85, 10/90, and 0/100), which are viewed as having TI and/or -DPE-I-DPE-I- (II) “diads.” The I moieties (1,3-linked isomers) were always found to be incorporated in the crystals and acted as “entropy or symmetry” defects that effectively decreased the equilibrium melting temperature Tmo and the rate of crystallization. However, the retardation of crystallization in PEKK 0/100 (the homopolymer with pure II diads) was significantly less than expected, which was attributed to the segregation of I moieties between the chains leading to a reduction of total entropy in the unit cells. The evidence of segmental segregation in PEKK 0/100 was seen in x-ray diffraction patterns, where several extra reflections were seen that could only be indexed by the published unit cell modified with a larger c-axis dimension (3.048 nm, corresponding to the length of six phenyl residues or 1.524 nm, the length of three phenyl residues). The composition of 15/85 was found to have the lowest value of Tmo and the slowest crystallization rate. Upon heating, the “II” crystals (T/I from 30/70 to 0/100) exhibited the conventional double-melting behavior rather than the triple-melting behavior as in the “TI” crystals (50/50 to 40/60). No indication of the second polymorph form 2 was found in “II” crystals. © 1994 John Wiley & Sons, Inc. 相似文献
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WANG Shu-Pinga GAO Dong-Zhaoa LIAO Dai-Zhenga JIANG Zong-Huia② YAN Shi-Pinga LI Li-Cuna b a 《结构化学》2006,(2)
1 INTRODUCTION Pyridyl-substituted nitroxide radicals have at- tracted considerable attention in recent years due to the ability to coordinate with metal ions and act as magnetic couplers, giving rise to new functional ma- terials with particular magnetic and optical prope- rties as well as a variety of structural topologies[1~3]. Considerable efforts have been made in designing and preparing multi-dimensional materials with app- ropriate bridges, such as pseudohalide, dicyanide, dicyanoa… 相似文献
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1 INTRODUCTION donor due to the presence of the protonated carboxyl group; (d) it can form short bridges via one car- Coordination polymers are of great interest due to boxylato end or long bridges via the benzene ring[7]. their physical properties and potential applications in We believe that coordination functionality of isoph- functional materials[1~3]. Aromatic polycarboxylic acids thalate can lead to interesting structures. In this com- such as 1,2,4,5-benzenetetracarboxylic acid[4],… 相似文献
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Poly(propylene adipate) (PPA) and poly(propylene isophthalate/adipate) (PPI-PPA) random copolymers of various compositions were synthesized in bulk and characterized in terms of chemical structure and molecular weight. Furthermore, the thermal behavior was examined by thermogravimetric analysis and differential scanning calorimetry. All the polymers showed a good thermal stability. At room temperature they appeared as semicrystalline materials, except the copolymers containing 20 and 30 mol% of PI units: the main effect of copolymerization was a lowering in the amount of crystallinity and a decrease of melting temperature with respect to homopolymers. The crystalline phase of PPI and PPA was evidenced at high content of propylene isophthalate or propylene adipate units, respectively. Amorphous samples were obtained after melt quenching and an increment of Tg as the content of PI units is increased was observed. This behavior was explained as due to the stiff phenylene groups in the polymeric chain. The Wood equation was found to describe well Tg-composition data. Lastly, the presence of a rigid-amorphous phase was evidenced in the copolymers, differently from PPA homopolymer. 相似文献
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