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1.
通过引入2,7-萘二磺酸(2,7-NDA2-)阴离子作为结构导向剂,与五元瓜环(Q[5])和过渡金属离子(Co2+、Ni2+、Zn2+、Cd2+)在水热条件下制备了4种新颖的Q[5]基超分子自组装体(Q[5]-SA),即{[M(H2O)4(Q[5])]·(NDA)}·x H2O(M=Co (1)、Ni (2)、Zn (3))和{[Cd2Cl2(H2O)4(Q[5])]·(NDA)}·13H2O (4)。单晶X射线衍射测试结果表明,自组装体1~3同构,其中Q[5]仅一端的部分端口羰基氧原子与金属离子配位形成简单配合物;而4中Q[5]的2个端口均与金属离子Cd2+配位形成了一维配位链。在自组装体1~4中,配体2,7-H2NDA均全脱质子,形成2,7-NDA2-阴离子平衡体系电荷,但均未能与金属离子配位,而在2,7-NDA2-阴离子与Q[5]外壁之间的瓜环外壁作用下进一步形成...  相似文献   

2.
通过引入2,7-萘二磺酸(2,7-NDA2-)阴离子作为结构导向剂,与五元瓜环(Q[5])和过渡金属离子(Co2+、Ni2+、Zn2+、Cd2+)在水热条件下制备了4种新颖的Q[5]基超分子自组装体(Q[5]-SA),即{[M (H2O)4(Q[5])]·(NDA)}·xH2O (M=Co (1)、Ni (2)、Zn (3))和{[Cd2Cl2(H2O)4(Q[5])]·(NDA)}·13H2O (4)。单晶X射线衍射测试结果表明,自组装体1~3同构,其中Q[5]仅一端的部分端口羰基氧原子与金属离子配位形成简单配合物;而4中Q[5]的2个端口均与金属离子Cd2+配位形成了一维配位链。在自组装体1~4中,配体2,7-H2NDA均全脱质子,形成2,7-NDA2-阴离子平衡体系电荷,但均未能与金属离子配位,而在2,7-NDA2-阴离子与Q[5]外壁之间的瓜环外壁作用下进一步形成三维超分子结构。此外,还研究了自组装体14的荧光传感性能,结果表明它们都能够作为抗生素诺氟沙星(NFX)的比率型荧光探针。  相似文献   

3.
Three coordination polymers [Mn(Nip)(Pbim)] n (1), [Co(Nip)(Pbim)] n (2) and [Zn(Nip)(Pbim)] n (3) [5-nitroisophthalate (Nip) and 2-(2-pyridyl)benzimidazole (Pbim)] were synthesised and characterised by elemental analysis, IR and single-crystal X-ray diffraction. Single-crystal X-ray diffraction analysis reveals that 1, 2 and 3 have 1-D ladder chain structures constructed from μ3-bridge Nip ligands and metal atoms. All of these chain-like structures are finally packed into supramolecular networks through hydrogen bonds and π–π stacking interactions. Fluorescence spectral method has been used for the study on the interaction of film sperm DNA with complexes. The results show that the corresponding fluorescence spectrum appeared and the intensity was enhanced with the growth of the concentration of DNA. All of the results indicate that there exists strong interaction of the complexes with DNA.  相似文献   

4.
利用荧光光谱法研究了环丙沙星与母体β-环糊精(β-CD)及其2种修饰衍生物羟丙基-β-环糊精(Hp-β-CD)、甲基-β-环糊精(Me-β-CD)形成的超分子体系,同时测定了3种超分子体系的猝灭常数和热力学参数.结果表明:环丙沙星与3种环糊精之间常温下均形成稳定的包合物;环丙沙星与3种环糊精包结过程中△G<0和△H<0,这说明环丙沙星与3种环糊精的包结能够自发进行而形成超分子体系,且反应为放热过程.通过对3种环糊精与环丙沙星的热力学数包结能力进行了比较,初步探讨了作用机理和影响包结能力大小的可能因素.  相似文献   

5.
The synthesis and thermomechanical properties of a novel class of self‐healing perfluoropolyethers (PFPEs) is reported. By decoration of 2‐ureido‐4[1H]‐pyrimidone end groups on the termini of low molar mass PFPE, the formation of supramolecular polymers and networks held together via hydrogen bonding associations was achieved. These novel supramolecular polymer materials exhibit a combination of enhanced modulus and elasticity, along with self‐healing properties, where rapid self‐healing time was demonstrated using dynamic rheological measurements. These types of supramolecular PFPEs are anticipated to be useful for a number of emerging areas in lubrication. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2013, 51, 3598–3606  相似文献   

6.
7.
New star polypseudorotaxanes that include 4,4′-dipyridyl-terminated 4-arm-poly(ethylene glycol) (PC1) and cucurbit[7]uril (CB[7]) were easily synthesised. The 1H NMR, UV–vis and resonance light scattering (RLS) data show that the viologen units of the star polypseudorotaxanes could fall off from the hydrophobic cavity of CB[7] with the addition of 1-adamantylamine (ADA). The cyclic voltammograms results indicate that the star polypseudorotaxanes have the redox property with the addition of ADA compared with the non-redox property of the pure star polypseudorotaxanes. The biological toxicity experiment shows that the bactericidal activity of the star polypseudorotaxanes in Escherichia coli was aroused by adjusting CB[7] dethreading from the star polypseudorotaxanes with the addition of another competitive guest ADA, which has a very high affinity for CB[7].  相似文献   

8.
ABSTRACT

A new bimodal triazole-bridged pyrene-appended calix[4]arene 2g has been synthesised and characterised and complexation studies showed that the binding of Cd2+ and Zn2+ occurs as demonstrated by enhanced monomer and declining excimer emission fluorescence spectral changes. With several other metal ions, quenching of both monomer and excimer emissions occurred. The observed monomer formation in the fluorescence spectra seen with Zn2+ and Cd2+ is possibly linked not just to the diminished parallel orientations of the pyrene rings but with the magnitude of the resulting HOMO-LUMO gaps and other parameters measured by DFT calculations.  相似文献   

9.
Novel molecular clips with anthracene sidewalls (1 a-c) were synthesized; they form stable host-guest complexes with a variety of electron-deficient aromatic and quinoid molecules. According to single-crystal structure analyses of clip 1 c and 1,2,4,5-tetracyanobenzene (TCNB) complex 14@1 b, the clips' anthracene sidewalls have to be compressed substantially during the complex formation to provide attractive pi-pi interactions between the aromatic guest molecule and the two anthracene sidewalls in the complex. The compression and expansion of aromatic sidewalls are calculated by molecular mechanics to be low-energy processes, so the energy required for compression of the anthracene sidewalls during complex formation is apparently overcompensated by the gain in energy resulting from the attractive pi-pi interactions. The finding that complexes of the clips 1 a-c are more stable than those of the corresponding clips 2 a-c can be explained in terms of the larger van der Waals contact surfaces of the anthracene sidewalls in 1 a-c (relative to the naphthalene sidewalls in 2 a-c). Color changes resulting from charge-transfer (CT) bands are observed in complex formation by 1 a-c: from colorless to red or purple with TCNB (14), and from yellow to green with 2,4,7-trinitro-9-fluorenone TNF (17). Independently, the host 1 b and guest 14 fluoresce from their respective excited singlet states, whilst in the complex 14@1 b the charge-transfer state quenches the higher-energy singlet states of the two components, and as a result luminescence is only observed from this new CT state. To the best of our knowledge, complex 14@1 b is the first example of CT luminescence from a host-guest complex. The binding constant determined for the formation of the TCNB complex 14@1 b from a UV/Vis titration experiment (Ka = 12 400 m(-1)) agrees well with the value (K(a) = 12 800 m(-1)) obtained by 1H NMR titration.  相似文献   

10.
利用水热方法合成了一种一维超分子链状四核镍夹心的砷钨酸盐[enH2][Ni(en)2]4[Ni4(H2O)2(α-AsW9O34)2].10H2O(1)(en=ethylene diamine);借助元素分析、红外光谱和单晶X射线衍射对其进行了表征。结果表明,化合物1的分子结构单元由1个二支撑的四核镍夹心砷钨酸盐多阴离子{[Ni(en)2]2[Ni4(H2O)2(α-AsW9O34)2]}6-,2个游离的[Ni(en)2]2+配离子,1个游离的双质子化[enH2]2+阳离子和10个结晶水分子组成。有趣的是,相邻的四核镍夹心砷钨酸盐多阴离子{[Ni(en)2]2[Ni4(H2O)2(α-AsW9O34)2]}6-借助Ni…O弱相互作用构筑一维超分子链状结构[Ni…O距离分布在0.253 2~0.283 7nm之间]。  相似文献   

11.
Novel ditopic receptors for guanosine have been prepared and characterised. Their association constants with a lipophilic guanosine derivative are somewhat smaller than the expected values for a guanosine-cytidine base pair, but remain in a useful range for building supramolecular structures.  相似文献   

12.
The interaction of toluidine blue (TB) with cyclodextrins (CDs), including β-cyclodextrin (β-CD) and carboxymethyl-β-cyclodextrin (CM-β-CD), and calf thymus DNA in aqueous solution is studied by ultraviolet-visible absorption and steady-state fluorescence technique. The interactive model of TB with double-stranded DNA has been investigated by means of the inclusive action of β-CD and CM-β-CD. Based on the changes of absorption, fluorescence and resonance light scattering (RLS) spectra, the intrinsic binding constant (Kap) and the binding site number (n) of TB with DNA and the inclusion complexes TB–CD with DNA are obtained in the case of 20 mmol L?1 Tris-HCl buffer solution (pH 7.2). According to the experimental results, it can be inferred that the interactive model of dimer TB with DNA is ‘electrostatic binding’, while the monomer TB with DNA is ‘intercalative binding’.  相似文献   

13.
Abstract

The octaanionic 5,11,17,23-tetrasulfonato-25,26,27,28-tetrakis(hydroxycarbonylmethoxy)-calix[4]arene (cone conformation) (C4TsTc) was investigated as a sensor for the biogenic tetracationic polyamine, spermine .(H4Spe4+). Fluorescence titration experiments of the water-soluble calixarene with spermine showed the formation of the 2:1 and 1:1 calixarene:spermine complexes in solution. The single crystal X-ray diffraction analysis of [(NaC4TsTc)4·(H4Spe)7] confirmed the formation of 2:1 and 1:1 calixarene:spermine species and showed that the water-soluble calixarene binds the spermine either by partially hosting it in the inner cavity or through the carboxylate groups on the lower rim. In order to investigate the effect of multivalent systems, supramolecular assemblies of octaanionic calixarene molecules templated by meso-tetrakis(4-N-methylpyridyl)porphyrin (H2T4) in different stoichiometric porphyrin:calixarene ratios (1:4 and 3:4) were also tested for spermine binding in solution. Fluorescence titration experiments with the 1:4 and 3:4 H2T4:C4TsTc supramolecular complexes showed that the multivalent assemblies are more sensitive to the presence of spermine than the calixarene alone.  相似文献   

14.
Two supramolecular complexes,[Ni(rac-L)]3[CrO4]2[ClO4]2-4H2O (1) and [meso-H2L]0.5[VO3]-0.16H2O (2) (L= 5,5,7,12,12,14-hexamethyl-1,4,8,11-tetraazacyclotetra-decane),have been prepared in an aqueous solu-tion,and detected by elemental analysis,IR,TG,and single crystal X-ray diffraction analyses. Com-pound 1 shows a one-dimensional hexagonal prism formed by the hydrogen bonding interactions between the secondary amines of rac-L and CrO42-anion/water molecules. Compound 2 displays a three-dimensional structur...  相似文献   

15.
16.
A binicotinic biscarbohydrazone compound,2,2'-bipyridyl-3,3'-bis(N,N'-disali- cylidene)-formyhydrazone,1 has been prepared and characterized by elemental analysis,FT-IR,1H- NMR,ESI-MS and single-crystal X-ray diffraction analysis. The crystal belongs to triclinic,space group P1 with a = 9.419(3),b = 11.745(4),c = 12.035(5)A,V = 1178.8(7)A^3,Z = 2,Dc = 1.354 g/cm^3,μ = 0.095 mm^-1,F(000) = 500,λ(MoKα) = 0.71073 ,C26H20N6O4,Mr = 480.48,the final R = 0.0480 and wR = 0.1084 for 3634 observed reflections with I 〉 2σ(I). Single-crystal X-ray diffraction analysis reveals that a 1D supramolecular structure of 1 has been constructed by multiply intermolecular N–H···N and O–H···O H-bonding interactions. Besides,compound 1 exhibits a strong green-light emission in the solid state at room temperature.  相似文献   

17.
基于大环自组装和多卤阴离子合成了有机-无机杂化超分子化合物,[(1,4-PMNH3)·(18-crown-6)]·[(H3O)·(18-crown-6)]2·[(H2O)·(18-crown-6)]·(18-crown-6)·(Bi2Cl9)(1)。化合物属正交晶系,Pca21空间群,a=2.4830(3)nm,b=1.1618(3)nm,c=3.3161(2)nm,V=9.566(2)nm3。并通过其红外光谱、粉末衍射、热重分析和单晶结构分析对化合物进行了充分表征。在转子定子型的超分子化合物1中,大环超分子阳离子和(Bi2Cl93-阴离子交错堆积形成包合物结构。并在室温下对其固体荧光性质进行测试表征。通过DSC对其热稳定性进行了详细分析。  相似文献   

18.
Alternating: a cofactor dyad consisting of a heme group (red in picture) and a bis(biotin) unit (blue) was synthesized and shown to specifically bind to both apomyoglobin and streptavidin. In the presence of the dyad, the 1:1 association of a disulfide-bridged myoglobin dimer (green) with streptavidin (gray) afforded a submicrometer-sized fibrous alternating copolymer.  相似文献   

19.
基于大环自组装和多卤阴离子合成了有机-无机杂化超分子化合物,[(1,4-PMNH3)·(18-crown-6)]·[(H3O)·(18-crown-6)]2·[(H2O)·(18-crown-6)]·(18-crown-6)·(Bi2Cl9)(1)。化合物属正交晶系,Pca21空间群,a=2.483 0(3)nm,b=1.161 8(3)nm,c=3.316 1(2)nm,V=9.566(2)nm3。并通过其红外光谱、粉末衍射、热重分析和单晶结构分析对化合物进行了充分表征。在转子定子型的超分子化合物1中,大环超分子阳离子和(Bi2Cl9)3-阴离子交错堆积形成包合物结构。并在室温下对其固体荧光性质进行测试表征。通过DSC对其热稳定性进行了详细分析。  相似文献   

20.
A new two-photon absorption compound,2-{4-((dicyanomethylidene-5,5-dimethylcyclohexl)vinyl]phenyl}imidazo[4,5- f][l,10]phenanthroline(DDVPIP),was synthesized and characterized.The one-photon excited fluorescence(OPEF) and two-photon excited fluorescence(TPEF) of DDVPIP are sensitive to the acid/base of the solution,which arc enhanced in basic solution but weakened in acidic solution.Charge-transfer(CT) states of DDVPIP were calculated through theory methods to explain its acid/ base-sensitive fluorescent properties.  相似文献   

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