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1.
A novel iodine-bridged mercury(Ⅱ) complex [Hg(L)(μ-I)(I)]2 was isolated by a reaction between HgI2 and the organic ligand tris[4-(1-pyrazolyl)phenyl]amine L, and the complex and ligand were both characterized by FT-IR spectroscopy, ^1H NMR and elemental analysis. The complex crystallizes in monoclinic space group P21/c with a = 9.579(5), b = 27.331 (5), c = 11.268(5) А, β= 105.624(5)°, Z = 2, Dc = 2.099 g·cm^-3 and μ= 7.620 mm^-1. The title complex C54H42Hg2I4N14 is a diplex bridged dinuclear complex consisting of two Hg(Ⅱ) ions, two ligands, two bridging I-anions, and two terminal I-anions. Universal hydrogen bonds in the complex with the partners of neighboring molecule have generated a supramolecular arrangement. Solid-state emission of the ligand and its complex have been investigated at room temperature.  相似文献   

2.
以四氯噻吩为原料,采用化学合成法制备了聚(3,4-二氯)噻吩.对影响合成材料结构规整度的溶剂极性进行了初步探讨,并采用元素分析、红外光谱、^13C NMR核磁谱等对目标产物进行了表征.结果表明,当采用极性较低的乙二醇二甲醚作溶剂时,可得到规整度较高的目标产物.  相似文献   

3.
Stannous-acetylacetonate was prepared efficiently and characterized by 1H NMR and FT-IR. Its catalytic activity for poly(trimethylene terephthalate) (PTT) synthesis was investigated. By this catalyst, the degree of esterification of pure terephthalic acid was up to 91.7% after reaction at 260°C for 2 h, while the intrinsic viscosity and content of ter- minal carboxyl groups of the corresponding PTT polymerized at 260°C, 60 Pa for 2 h was 0.8816 dL/g and 17 mol/t, respectively. Stannous-acetylacetonate was more active and promising than tetrabutyl titanate and stannous octoate for PTT synthesis.  相似文献   

4.
Blends of poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBHHx) and poly(butylene succinate-adipate) (PBSA), both biodegradable semicrystalline polyesters, were prepared with the ratio of PHBHHx/PBSA ranging from 80/20 to 20/80 by melt mixing method. Differential scanning calorimetry (DSC), thermogravimetry analysis (TGA), dynamic mechanical thermal analysis (DMA), polarizing optical microscopy (POM) and wide angle X-ray diffractometer (WAXD) were used to study the miscibility and crystallization behavior of PHBHHx/PBSA blends. Experimental results indicate that PHBHHx is immiscible with PBSA as shown by the almost unchanged glass transition temperature and the biphasic melt.  相似文献   

5.
本文综述了手性亚膦(磷)酸联二萘酚酯及手性亚膦(磷)酸联二萘酚胺酯配体在不对称催化应用中的最新进性。  相似文献   

6.
采用溶剂热法,丁烷四羧酸(H4L)与水合乙酸钴经配位聚合反应合成了一个新型的双核Co(Ⅱ)聚合物[Co2L(MeOH)(H2O)4]n.nH2O(1),其结构经元素分析和单晶X-射线衍射表征。1属单斜晶系,C2/c空间群,晶胞参数a=2.802 6(3)nm,b=0.816 32(11)nm,c=1.630 1(2)nm,β=119.793(2)°,V=3.236 5(7)nm3,Z=8,Dc=1.925 Mg.cm-3,R1=0.097 5,wR2=0.223 1。1通过H4L桥联形成一维链,通过O-H┈O氢键作用形成了无限延伸的二维网络结构;在1中存在的分子内及分子间氢键使1具有三维网络结构。  相似文献   

7.
在生物活性肽研究中,通过在肽主链中引入特定结构的氨基酸,得到其活性类似物,可以使人们进一步认识肽结构与生物活性之间的关系,发展高活性、低副作用的肽类药物。蛋白氨基酸的结构都是一定的,不能满足研究工作的需要,所以需要设计合成特定结构的非蛋  相似文献   

8.
赵琨  林一超 《应用化学》1990,7(5):45-48
本文研究了乙胺等四种正胺配体与Cu(ClO_4)_2的配位络合物溶液的低温(77K)ESR谱。用超精细耦合常数和g值计算了σ键强度以及配位场分裂能次序。结果表明:σ键强度随着配位胺分子碳链增长而增强,至正戊胺配位络合物开始减弱;在这些Cu(Ⅱ)-正胺络合物中氨基以与氨不同的键性和Cu(Ⅱ)离子键合。  相似文献   

9.
利用溶剂热法合成了一维配位聚合物[Er(CCA)3(H2O)2]n·2nH2O(HCCA=香豆素-3-羧酸),通过元素分析和IR对配合物进行了表征,用X-射线单晶衍射技术测定了其晶体结构.标题配合物晶体属于单斜晶系,P21/c空间群:a=0.6310(1)nm,b=1.4165(2)nm,c=3.1731(3)nm;β...  相似文献   

10.
The polymerization of n-hexyl isocyanate (HNCO) was carried out in the presence of a novel single initiator, rare earth tris (2,6-di-tert-butyl-4-methylphenolate) [Ln(OAr)3]. The influences of reaction conditions such as the monomer concentration, the polymerization temperature and time, and the types of solvents on the polymerization of HNCO were studied. Polymerizations of phenyl, i-propyl, p-tolyl, n-butyl and n-octyl isocyanates with La(OAr)3 were also examined.  相似文献   

11.
A facile, efficient technique was built to synthesize a supramolecular material containing quadruple hydrogen bonding sites. The current approach presented here involves a single-step reaction between the amine of precursor, e.g. methyl isocytosine (MIC) and the epoxy group of polymer, e.g. poly(ethylene glycol diglycidyl ether) (PEG DGE, Mn = 526 g/mol, as verified using 1H NMR and FT-IR spectroscopy. Wide angle X-ray scattering (WAXS), UV/visible spectroscopy and differential scanning calorimeter (DSC) clearly show that the product is not a simple mixture of two components, but the supramolecular polymer containing quadruple hydrogen bonding sites. Complex melt viscosities reveal that mechanical properties of the supramolecular polymer are enhanced by more than 104 times compared to the pristine low molecular weight polymer, giving rise to the significant change of physical state from liquid to solid. Current approach also illustrates an advantageous route because it does not need the selective use of monofunctionalized precursor and not produce a dead, difunctionalized precursor.  相似文献   

12.
The monomer 2,6,12-triaminotriptycene was synthesized and the structure was confirmed by IR and 1H NMR spectra. Hyperbranched polyimides modified with different terminal groups were obtained from precursors, anhydride- and aminoterminated hyperbranched poly(amic acid)s from polymerization of A2 + B3 system. From gel permeation chromatograrn (GPC) characterization, representative products had high molecular weight. All polymers had good solubility in CHCl3, DMF and tetrahydrofuran (THF), and performed no detective Tgs in the range of 50-300 ℃ and high Tds above 455 ℃ when 5% weight loss.  相似文献   

13.
A supramolecular material containing quadruple hydrogen bonding sites was prepared by reacting the amines of methyl isocytosine and the epoxy groups of poly (ethylene glycol diglycidyl ether). This supramolecular polymer was complexed with metal salt, that is potassium iodide, to produce polymer electrolytes, and their physical properties, specific interactions, and conductivity behavior were investigated. The ionic conductivity of polymer electrolytes continuously increased with increasing salt concentration up to 0.4 of salt weight fraction, presenting usually high solubility limit of salt in the supramolecular polymer. Wide angle X‐ray scattering data also presented that the metal salt was completely dissolved in the supramolecular polymer up to 0.4 of salt weight fraction. Upon the introduction of metal salt, the mechanical properties of the supramolecular polymer were significantly enhanced by around 10 times and the glass transition temperature of the polymer increased by about 50 °C, as revealed by complex melt viscosities and differential scanning calorimetry. These unusual behaviors of salt solubility and mechanical properties for supramolecular polymer/metal salt complexes were attributed to the strong, additional metal ion coordination to hydrogen bonding sites as well as ether oxygens of polymer matrix, as supported by FTIR spectroscopy. © 2007 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 3181–3188, 2007  相似文献   

14.
A series of systematically varied ’rigid-rod’ octahedral ruthenium-acetylide complexes, bearing conjugated bis(acylamino)triazine (DAT) substituents capable of ADAD-DADA pairing, of general formula trans-[(dppe)2Ru(Cl)(CC-C6H4-DAT(R)2)] (R = Et, i-Pr, t-Bu, n-C5H11) have been synthesized and thoroughly characterized in solution by 1H NMR and in the solid state. trans-[Ru(-CC-C6H4-DAT(R)2)2(dppe)2] (R = n-C5H11) has also been designed to form discrete oligomeric chains in solution.  相似文献   

15.
[structures: see text] In this article we describe a rational approach for prefixing multiple cooperative binding sites in an ideal spatial arrangement on a structurally rigid backbone, constrained exclusively by intramolecular hydrogen bonding. The idea is exemplified by the ability of the self-assembling constructs 1a-e and 2a,b to form hydrogen-bonded dimers, whose structural preorganization has been solely effected by intramolecular hydrogen bonding. The readily accessible amidinourea backbone has been used as a common platform for the construction of a variety of such self-assembling systems. ESI mass spectrometry and single-crystal X-ray diffraction studies have been particularly effective in investigating the self-assembling propensities of these systems. Remarkably, most the H-bonded dimers reported herein undergo an unusual mode of self-assembly, using intermolecular four-membered ring hydrogen-bonded interaction, affording extended supramolecular networks.  相似文献   

16.
HSCH2CONHCH3 and HSCH2CON(CH3)2 containing a peptide bond are prepared for the synthesis of DNICs with/without intra-molecular hydrogen bonding, respectively. The IR ν(NO) bands of [(NO)2Fe(SCH2CONHCH3)2] (2) appears at 1751, 1700 cm−1. In complex 2, the presence of intramolecular [NH?S] hydrogen bonding was verified by the observation of IR spectroscopy with N−H stretching frequency 3334 cm−1 (CDCl3) and subsequently confirmed by single-crystal X-ray diffraction showing N−S distance of 2.94 Å. Complex 2 displays the rhombic EPR spectrum with g1 = 2.039, g2 = 2.031 and g3 = 2.013 at in frozen H2O. Complexes 2 and 3 rapidly release NO when exposed to light. The time needed for photolysis reactions of 2 is two times faster than that of 3 in less polar solvent. Representative time courses for the photolability of 2 and 3 in THF display the NO-off ability: 2 > 3.  相似文献   

17.
刘向阳 《高分子科学》2015,33(4):621-632
The effect of benzimidazole units on thermal imidizaiton was studied when they were introduced into the main chain of poly(amic acid)(PAA). The thermal imidization process of PAA-PABZ synthesized by 3,3',4,4'-biphenyltetracarboxylic dianhydride(BPDA) and 2-(4-aminophenyl)-5(6)-aminobenzimidazole(PABZ) was studied by TGA, DSC, DMA, FTIR and in situ FTIR. The results of FTIR and in situ FTIR indicate benzimidazole units act as an "in situ" catalyst to accelerate thermal imidization of PAA to polyimide(PI) when the temperature is lower than 170 °C. FTIR and 1H-NMR results demonstrate that in situ catalysis is caused by the hydrogen bonding interactions between C=N of benzimidazole and ―NH― in ―CONH― of PAA and the semi-ionization of the H in imidazole ring of benzimidazole. However, when the imidization temperature is higher than 170 °C, the thermal imidization process is inhibited. DMA and in situ FTIR results illustrate that the decreased mobility of PI-PABZ macromolecular chains and the reduced reactive ability of anhydride formed during the intramolecular breakdown of polymer chains lead to the inhibition of thermal imidization process.  相似文献   

18.
To realize the pH-targeting delivery of antitumor drug cis-dichlorodiammineplatinum(II) (cisplatin, CDDP), a tumor pH-responsive polymer-platinum(II) complex (Suc-HPMHO-CDDP) from carboxyl-modified hyperbranched polyether (Suc-HPMHO) and cisplatin was designed and prepared. Because of the existence of hydrophobic core and ionization of surface carboxylic acid, Suc-HPMHO showed reversible pH-response in aqueous solution, and its responding pH value could be readily adjusted by only changing the degree of carboxylation of Suc-HPMHO. With plenty of terminal carboxyl groups, Suc-HPMHO could form the complex with CDDP by substituting the chloride ions with carboxyls. Methyl tetrazolium (MTT) assay showed that Suc-HPMHO had low cytotoxicity, while Suc-HPMHO-CDDP complex presented a similar antitumor effect with the free CDDP. Under the tumor acidic pH (pH(e)), Suc-HPMHO-CDDP complex deposited around/in cells because of its pH-response. Therefore, the pH-targeting of Suc-HPMHO-CDDP complex to tumor tissue could be realized. All of these results show that the tumor pH-responsive Suc-HPMHO-CDDP complex is a potential pH-targeting drug delivery system in cancer therapy.  相似文献   

19.
The reactions of K3[Cu(CN)4], 3-acetylpyridine (3-Acpy) or 4-acetylpyridine (4-Acpy) in the presence of Me3SnCl in H2O/acetonitrile media at room temperature afford the 3D-supramolecular coordination polymers (SCPs)3[Cu2CN(μ-CN)·(3-Acpy)2] 1 and 3[Cu2CN(μ-CN)·(4-Acpy)2] 2. The structures of 1 and 2 consist of Cu2CN building blocks which are connected by CN groups, forming 1D-zig-zag chains. Each chain is bonded to another chain by hydrogen bonding into a 2D-layer, which is further stacked in an interwoven mode by π–π stacking interactions and hydrogen bonds in 1 and 2, as well as Cu···Cu interactions in 1, to create supramolecular 3D-network structures. The high dimensional topologies of 1 and 2 result mainly from extensive hydrogen bonding and π–π stacking. The long wavelength absorption band at 400–420 nm in the electronic spectra of 1 and 2 is assigned to a CT from copper(I) to the Acpy ligand. Compound 2 exhibits strong luminescence at 485 and 527 nm, corresponding to MLCT and metal-centered transitions, respectively.  相似文献   

20.
Hyperbranched poly(amido amine)s (HPAA) show weak photoluminescence, however, they have shown strong emission after short polyethylene glycol (PEG) chains have been linked onto HPAA macromolecule via Michael addition reaction. These PEGylated hyperbranched poly(amido amine)s show low cytotoxicity and potential application in cell imaging.  相似文献   

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