Synthese und Koordinationschemie eines neuartigen Bistetrazols: Ein 1D-Metallopolymer durch Selbstorganisation koordinativ ungesättigter Zink(II)-M4onomere [1] / Synthesis and Coordination Chemistry of a New Bistetrazole: A 1D-Metallopolymer via Self-Assembly of Monomeric Zinc(II)-Buildingblocks

1995 ◽  
Vol 50 (4) ◽  
pp. 642-648 ◽  
Author(s):  
Rolf W. Saalfrank ◽  
Klaus Schobert ◽  
Stefan Trümmer ◽  
Alexander Wolski

The new bistetrazole 13 has been obtained by subsequent formation of the two heterocyclic units. In methanolic solution 13 reacts with zinc(II) acetate to yield the pseudo-meso-1 D-coordination polymer [ZnL2(MeOH)]n (n = ∞) 14. The structure of 14 was established by single crystal X-ray diffraction. The generation of the polymeric chain 14 is understandable, if intermediate formation of coordinatively unsaturated zinc(II) buildingblocks (Δ)-15 and (Λ)-15 is assumed. Alternating linkage of the self-complementary chiral monomers 15, across one cyanofunction each, leads to 14 with zinc being essentially octahedrally coordinated. Compared with polymeric compounds of similar bridging ligands, the Zn ··· N≡C-distance in 14 (225,7 pm) is short.

2010 ◽  
Vol 74 ◽  
pp. 38-47
Author(s):  
Clay Mortensen ◽  
Paul Zschack ◽  
David C. Johnson

The evolution of designed [(Ti-Te)]x[(Sb-Te)]y, [(Bi-Te)]x[(Sb-Te)]y, [(Ti-Te)]w[(Bi-Te)]x[(Sb-Te)]y and [(Ti-Te)]w[(Bi-Te)]x[(Ti-Te)]y[(Sb-Te)]z precursors were followed as a function of annealing temperature and time using both low and high angle x-ray diffraction techniques to probe the self assembly into nanolaminate materials. The [(Bi-Te)]x[(Sb-Te)]y precursors were found to interdiffuse at low temperatures to form a (BixSb1-x)2Te3 alloy. The [(Ti-Te)]x[(Bi-Te)]y and [(Ti-Te)]x[(Sb-Te)]y precursors formed ordered nanolaminates [{(TiTe2)}1.35]x[Bi2Te3]y and [{(TiTe2)}1.35]x[Sb2Te3]y respectively. The [(Ti-Te)]w[(Bi-Te)]x[(Sb-Te)]x precursors formed [{(TiTe2)}1.35]w[(Bi0.5Sb0.5)2Te3]2x nanolaminates on annealing, as the bismuth and antimony layers interdiffused. Over the range of TiTe2 thicknesses used in [(Ti-Te)]w[(Bi-Te)]x[(Ti-Te)]y[(Sb-Te)]z precursors, Bi and Sb were found to interdiffuse through the 2-4 nm thick Ti-Te layers, resulting in the formation of (BixSb1-x)2Te3 alloy layers as part of the final nanolaminated products. When the Bi-Te and Sb-Te thicknesses were equal in the amorphous precursors, symmetric [{(TiTe2)}1.35]m[(Bi0.5Sb0.5)2Te3]n nanolamiantes were formed. When the thicknesses of Bi-Te and Sb-Te layers were not equal in the amorphous precursor, asymmetric [(TiTe2)1.35]m[(BixSb1-x)2Te3]n[(TiTe2)1.35]m[(BixSb1-x)2Te3]p nanolaminates were formed. These results imply that to form (A)w(B)x(C)y nanolaminates using designed layered precursors all three components must be immiscible. To form (A)x(B)y(A)x(C)z nanolaminates, the components must be immiscible or the precursor to the A component and the A component itself must be an effective interdiffusion barrier preventing B and C from mixing.


2015 ◽  
Vol 68 (2) ◽  
pp. 322 ◽  
Author(s):  
Wenlong Liu ◽  
Mengqiang Wu ◽  
Xueying Wang ◽  
Wei Wang ◽  
Dayu Liu ◽  
...  

Using a hydrothermal synthesis, the self-assembly of MnII ions and 1,4-bis(1-imidazol-yl)-2,5-dimethyl benzene with two dicarboxylate ligands, 2-nitrobenzene-1,4-dicarboxylic acid (2-H2ata) and 5-methylbenzene-1,3-dicarboxylic acid (5-CH3-H2ip) constructed two interesting coordination polymers: [Mn(2-ata)(bimb)]n (1) and {[Mn(5-CH3-ip)(bimb)1.5]·2H2O}n (2), where bimb refers to 1,4-bis(1-imidazol-yl)-2,5-dimethyl benzene. Their structures were determined by single-crystal X-ray diffraction, elemental analysis, and infrared spectroscopy. Complex 1 exhibits a 2-fold interpenetrated pcu net. Complex 2 shows an unusual polycatenated 2D+2D→3D framework. In addition, the solid-state photoluminescent properties of 1 and 2 were investigated at room temperature.


2013 ◽  
Vol 834-836 ◽  
pp. 913-916
Author(s):  
Zhao Qiang Zheng ◽  
Huan Yu Wu ◽  
Bing Wang

In2O3nanotowers have been fabricated on Au item-shaped parallel electrodes using thermal evaporation of the mixed powders of In2O3and graphite with Au catalysts. The morphology and structure of the prepared nanorods are determined on the basis of field-emission scanning electron microscopy (FESEM) and x-ray diffraction (XRD). The self-assembly grown sensors of In2O3nanotowers have excellent performance in sensor response to hydrogen concentration of 1000 ppm under operated temperature of 300°C.


2017 ◽  
Vol 73 (4) ◽  
pp. 314-318 ◽  
Author(s):  
Xu Wei ◽  
Jian-Hua Li ◽  
Qiu-Ying Huang ◽  
Xiang-Ru Meng

The unsymmetrical N-heterocyclic ligand 1-[(benzotriazol-1-yl)methyl]-1H-1,3-imidazole (bmi) has three potential N-atom donors and can act in monodentate or bridging coordination modes in the construction of complexes. In addition, the bmi ligand can adopt different coordination conformations, resulting in complexes with different structures due to the presence of the flexible methylene spacer. Two new complexes, namely bis{1-[(benzotriazol-1-yl)methyl]-1H-1,3-imidazole-κN3}dibromidomercury(II), [HgBr2(C10H9N5)2], and bis{1-[(benzotriazol-1-yl)methyl]-1H-1,3-imidazole-κN3}diiodidomercury(II), [HgI2(C10H9N5)2], have been synthesized through the self-assembly of bmi with HgBr2or HgI2. Single-crystal X-ray diffraction shows that both complexes are mononuclear structures, in which the bmi ligands coordinate to the HgIIions in monodentate modes. In the solid state, both complexes display three-dimensional networks formed by a combination of hydrogen bonds and π–π interactions. The IR spectra and PXRD patterns of both complexes have also been recorded.


2010 ◽  
Vol 434-435 ◽  
pp. 597-600
Author(s):  
Xiao Hong Liang ◽  
Jun Hui Xiang ◽  
Fu Shi Zhang ◽  
Li Xing ◽  
Bo Song ◽  
...  

In this paper, the crystallization behavior of calcium carbonate between the organic-water interfaces using a slow gas-diffusion procedure is studied. The organic-water interfaces can control the crystallization of calcium carbonate to form a flower-shaped superstructure. The precipitates of calcium carbonate were identified by X-ray diffraction (XRD) and scanning electron microscopy (SEM). A possible mechanism about the self-assembly process of CaCO3 crystals has been analyzed. It is found that the morphology of CaCO3 superstructure depends on the properties of organic solvent. This paper also presents the influence of surfactant monolayer, between the biphase interfaces, on the CaCO3 superstructure. This study suggests that it is possible to control morphogenesis of calcium carbonate by a combination of a surfactant monolayer with the organic-water interfaces.


2011 ◽  
Vol 311-313 ◽  
pp. 485-488 ◽  
Author(s):  
Shuai Zhang ◽  
Qing Ping Ke ◽  
Lei Zhang ◽  
Tian Di Tang

Formation of layered nanosheets and micro-spheres from a simple self-assembly and polycondensation of n-octadecylsilane (PODS) in water and toluene is demonstrated, respectively. The structure of the micro-spheres was characterized by Scanning Electron Microscope (SEM), Transmission Electron Microscopy (TEM) and X-ray Diffraction (XRD). According to the TEM images, it was firstly confirmed that the micro-spheres consist of stacks of bilayered polymerized n-octadecylsilane with head-to-head arrangements. The co-effects of water and solvent were proposed to control the octadecyltrichlsilane hydrolysis process and eventually the morphology of the micro-spheres. A micelle formation mechanism for the formation of the PODS micro-spheres under the co-effects of water and solvent were firstly proposed.


2015 ◽  
Vol 11 ◽  
pp. 2343-2349 ◽  
Author(s):  
Xiang Sun ◽  
Guoqiao Lai ◽  
Zhifang Li ◽  
Yuwen Ma ◽  
Xiao Yuan ◽  
...  

This paper reports the self-assembly of two new tetrathiafulvalene (TTF) derivatives that contain one or two urethane groups. The formation of nanoribbons was evidenced by scanning electron microscopy (SEM) and X-ray diffraction (XRD), which showed that the self-assembly ability of T 1 was better than that of T 2 . The results revealed that more urethane groups in a molecule did not necessarily instigate self-assembly. UV–vis and FTIR spectra were measured to explore noncovalent interactions. The driving forces for self-assembly of TTF derivatives were mainly hydrogen bond interactions and π–π stacking interactions. The electronic conductivity of the T 1 and T 2 films was tested by a four-probe method.


2016 ◽  
Vol 852 ◽  
pp. 653-656
Author(s):  
Li Sun ◽  
Lin Zhu ◽  
Jun Peng Xie ◽  
Rui Fang Guan

It is very important to form a stable, structure-controlled material by molecular assembly inthe fields of materials and life science. How cyclodextrins affect the self–assembly behavior of inclusion compounds becomes the focus recently, due to the advantages of selectivity, regulating, capability, biocompatibility and other interesting properties. In thispaper, polyoxyethylene ω-tristyrylphenyl methacrylate (SEM-25) and α-cyclodextrin (α-CD) form inclusion compound (AS) firstly, then copolymer of AS and methyl methacrylate (MMA) - the comb-like polyrotaxanes (CD-PR) were prepared through the redox initiationsystem of free radical polymerization. Furthermore, the self-assembling behavior of CD-PR is studied, it is found that solvent has an great impact on aggregation morphology of CD-PR without changing composition of the polyrotaxanes. Products were characterized by X-ray diffraction (XRD), nuclear magnetic resonance (1H NMR) and scanning electron microscope (SEM).


2014 ◽  
Vol 10 ◽  
pp. 432-441 ◽  
Author(s):  
Rainer Hovorka ◽  
Sophie Hytteballe ◽  
Torsten Piehler ◽  
Georg Meyer-Eppler ◽  
Filip Topić ◽  
...  

Two new 9,9’-spirobifluorene-based bis(4-pyridines) were synthesised in enantiopure and one also in racemic form. These ligands act as concave templates and form metallosupramolecular [(dppp)2M2L2] rhombi with cis-protected [(dppp)Pd]2+ and [(dppp)Pt]2+ ions. The self-assembly process of the racemic ligand preferably occurs in a narcissistic self-recognising manner. Hence, a mixture of all three possible stereoisomers [(dppp)2M2{(R)-L}2](OTf)4, [(dppp)2M2{(S)-L}2](OTf)4, and [(dppp)2M2{(R)-L}{(S)-L}](OTf)4 was obtained in an approximate 1.5:1.5:1 ratio which corresponds to an amplification of the homochiral assemblies by a factor of approximately three as evidenced by NMR spectroscopy and mass spectrometry. The racemic homochiral assemblies could also be characterised by single crystal X-ray diffraction.


2009 ◽  
Vol 87 (1) ◽  
pp. 205-211 ◽  
Author(s):  
Barry A Blight ◽  
James A Wisner ◽  
Michael C Jennings

Previous studies have determined that neutral palladium(II) dibromide complexes template the formation of [2]pseudorotaxanes, albeit with weaker affinities than the analogous palladium(II) dichloride species. Here, the self-assembly of both [2]rotaxane (2) and [2]catenane (5) were attempted using a PdBr2L2 centre as the template, resulting in the desired interlocked structures. The structures were confirmed by NMR spectroscopy, CSI-MS, and single crystal X-ray diffraction analyses. [2]Rotaxane 2 was isolated in 53% and [2]catenane 5 in 41% yields. The lower yields observed in comparison to the chloride analogues can be attributed to the reduced template effect of the palladium(II) dibromide subunits, caused by both the poor steric fit of the bromides in the isophthalamide cleft and bromide’s reduced capacity as a hydrogen bond acceptor.Key words: rotaxane, catenane, hydrogen bonding, interlocked, supramolecular chemistry.


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