共查询到20条相似文献,搜索用时 15 毫秒
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pH‐Modulated Molecular Assemblies and Surface Properties of Metal–Organic Supercontainers at the Air–Water Interface 下载免费PDF全文
Nathan L. Netzer Dr. Feng‐Rong Dai Prof. Zhenqiang Wang Prof. Chaoyang Jiang 《Angewandte Chemie (International ed. in English)》2014,53(41):10965-10969
The orientation of metal–organic supercontainer (MOSC) molecules in Langmuir films was systematically studied at the air–water interface. The acidity of the aqueous subphases plays a significant role in tuning the orientation of MOSC molecules in the Langmuir films. Furthermore, Langmuir–Blodgett films of MOSCs were prepared and the uniform multilayer structures demonstrated various surface properties, depending on their conditions of fabrication. Our use of Langmuir films provides a novel approach to access tunable assemblies of MOSC molecules in two‐dimensional thin films. 相似文献
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A Supramolecular Sorting Hat: Stereocontrol in Metal–Ligand Self‐Assembly by Complementary Hydrogen Bonding 下载免费PDF全文
Michael C. Young Lauren R. Holloway Amber M. Johnson Prof. Richard J. Hooley 《Angewandte Chemie (International ed. in English)》2014,53(37):9832-9836
A combination of self‐complementary hydrogen bonding and metal–ligand interactions allows stereocontrol in the self‐assembly of prochiral ligand scaffolds. A unique, non‐tetrahedral M4L6 structure is observed upon multicomponent self‐assembly of 2,7‐diaminofluorenol with 2‐formylpyridine and Fe(ClO4)2. The stereochemical outcome of the assembly is controlled by self‐complementary hydrogen bonding between both individual ligands and a suitably sized counterion as template. This hydrogen‐bonding‐mediated stereoselective metal–ligand assembly allows the controlled formation of nonsymmetric discrete cage structures from previously unexploited ligand scaffolds. 相似文献
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Prof. Dr. Hiromitsu Maeda Ryo Akuta Dr. Yuya Bando Dr. Kazuto Takaishi Prof. Dr. Masanobu Uchiyama Dr. Atsuya Muranaka Prof. Dr. Norimitsu Tohnai Prof. Dr. Shu Seki 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(35):11676-11685
Polygon‐like [2+2]‐ and [3+3]‐type metal complexes were prepared from dipyrrin dimers connected by acute‐angled spacers. The electrical conduction depends strongly on the packing alignment of the compounds, revealing the presence of effective hopping pathways for holes with relatively high mobility up to 0.11 cm2 V?1 s?1 along the aligned axis of [3+3]‐type metal‐bridged assemblies. These observations correlated with the geometrical control of the π‐conjugated metal complexes in the cyclic structures, which enables their ordered arrangement in the assemblies. 相似文献
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Multi‐Pyrene Assemblies Supported on Stannoxane Frameworks: Synthesis,Structure and Photophysical Studies 下载免费PDF全文
Subrata Kundu Ramesh K. Metre Rajeev Yadav Dr. Pratik Sen Dr. Vadapalli Chandrasekhar 《化学:亚洲杂志》2014,9(5):1403-1412
Organostannoxanes have been used as scaffolds for the preparation of multi‐chromophore assemblies. A single‐step synthesis procedure allows the preparation of compounds in which the number of chromophore units can be varied from two to six. Thus, the reactions of pyrene sulfonic acid (PySO3H) or C16H9CHNC6H3(COOH)2 (LH2) with various organotin precursors gave pyrene‐containing organostannoxanes, that is, [Ph3SnPySO3]6 ( 1 ), [{(Me2Sn)2(μ3‐O)(μ‐OH)PySO3}2{(Me2Sn)2(μ3‐O)(μ‐OH)H2O}2 ? 2 PySO3] ( 2 ), [{tBu2Sn(OH)PySO3}2] ( 3 ), [{(nBuSn)12(O)14(OH)6{PySO3}2] ( 4 ), and [{(nBu2Sn)L}3]2 ? C6H5CH3 ( 5 ). Compounds 1 – 5 were characterized by using X‐ray crystallography. Compounds 1 and 5 are 24‐membered macrocycles. Macrocycle 1 possesses intramolecular π–π stacking interactions. An unusual co‐crystal of two tetrameric ladders in 2 was observed in which one of the components of the co‐crystal is neutral whereas the other is dicationic and two pyrenesulfonate counterions are present to balance the overall charge. In the solid state these compounds reveal rich supramolecular structures. Photophysical studies on 1 – 5 reveal that interactions in the solid state lead to considerable broadening of the emission bands. 相似文献
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Valentina Abet Filip T. Szczypiski Marc A. Little Valentina Santolini Christopher D. Jones Robert Evans Craig Wilson Xiaofeng Wu Michael F. Thorne Michael J. Bennison Peng Cui Andrew I. Cooper Kim E. Jelfs Anna G. Slater 《Angewandte Chemie (International ed. in English)》2020,59(38):16755-16763
Many interesting target guest molecules have low symmetry, yet most methods for synthesising hosts result in highly symmetrical capsules. Methods of generating lower symmetry pores are thus required to maximise the binding affinity in host–guest complexes. Herein, we use mixtures of tetraaldehyde building blocks with cyclohexanediamine to access low‐symmetry imine cages. Whether a low‐energy cage is isolated can be correctly predicted from the thermodynamic preference observed in computational models. The stability of the observed structures depends on the geometrical match of the aldehyde building blocks. One bent aldehyde stands out as unable to assemble into high‐symmetry cages‐and the same aldehyde generates low‐symmetry socially self‐sorted cages when combined with a linear aldehyde. We exploit this finding to synthesise a family of low‐symmetry cages containing heteroatoms, illustrating that pores of varying geometries and surface chemistries may be reliably accessed through computational prediction and self‐sorting. 相似文献
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Jack K. Clegg Dr. Simon S. Iremonger Dr. Michael J. Hayter Peter D. Southon Dr. René B. Macquart Dr. Martin B. Duriska Dr. Paul Jensen Dr. Peter Turner Dr. Katrina A. Jolliffe Prof. Cameron J. Kepert Prof. George V. Meehan Prof. Leonard F. Lindoy Prof. 《Angewandte Chemie (International ed. in English)》2010,49(6):1075-1078
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The Regioselectivity of Bingel–Hirsch Cycloadditions on Isolated Pentagon Rule Endohedral Metallofullerenes 下载免费PDF全文
Dr. Marc Garcia‐Borràs Dr. Maira R. Cerón Dr. Sílvia Osuna Dr. Marta Izquierdo Dr. Josep M. Luis Prof. Dr. Luis Echegoyen Prof. Dr. Miquel Solà 《Angewandte Chemie (International ed. in English)》2016,55(7):2374-2377
In this work, the Bingel–Hirsch addition of diethylbromomalonate to all non‐equivalent bonds of Sc3N@D3h‐C78 was studied using density functional theory calculations. The regioselectivities observed computationally allowed the proposal of a set of rules, the predictive aromaticity criteria (PAC), to identify the most reactive bonds of a given endohedral metallofullerene based on a simple evaluation of the cage structure. The predictions based on the PAC are fully confirmed by both the computational and experimental exploration of the Bingel–Hirsch reaction of Sc3N@D5h‐C80, thus indicating that these rules are rather general and applicable to other isolated pentagon rule endohedral metallofullerenes. 相似文献
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Yao‐Rong Zheng Hai‐Bo Yang Prof. Dr. Koushik Ghosh Liang Zhao Dr. Peter J. Stang Prof. Dr. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2009,15(29):7203-7214
The self‐organization of multicomponent supramolecular systems involving a variety of two‐dimensional (2 D) polygons and three‐dimensional (3 D) cages is presented. Nine self‐organizing systems, SS1 – SS9 , have been studied. Each involves the simultaneous mixing of organoplatinum acceptors and pyridyl donors of varying geometry and their selective self‐assembly into three to four specific 2 D (rectangular, triangular, and rhomboid) and/or 3 D (triangular prism and distorted and nondistorted trigonal bipyramidal) supramolecules. The formation of these discrete structures is characterized using NMR spectroscopy and electrospray ionization mass spectrometry (ESI‐MS). In all cases, the self‐organization process is directed by: 1) the geometric information encoded within the molecular subunits and 2) a thermodynamically driven dynamic self‐correction process. The result is the selective self‐assembly of multiple discrete products from a randomly formed complex. The influence of key experimental variables ‐ temperature and solvent ‐ on the self‐correction process and the fidelity of the resulting self‐organization systems is also described. 相似文献
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Metal–organic polyhedra (MOPs) are discrete, metal–organic molecular entities composed of edge‐sharing molecular polygons or connected molecular vertices. Unlike the infinite metal–organic coordination networks popularized by metal–organic frameworks (MOFs), spherical MOPs, also known as nanocages, nanospheres, nanocapsules, or nanoballs, are obtained through the self‐organization of metal–carboxylate or metal–pyridine/pyrimidine links to afford cage‐like nanoarchitectures. MOPs offer much promise as porous materials owing to their well‐defined structures and solution processability. However, these advantages become moot if their poor aqueous stability and/or guest‐removal‐induced aggregation handicaps remain unaddressed. The concise premise of this contribution limits our discussion to the design principles in action behind recent developments in stable carboxylate MOPs. To highlight the structure–property relationships between the structural and compositional features of these metal carboxylate polyhedra, related scientific challenges and state‐of‐the‐art research directions for further exploration are presented in brief. 相似文献
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Metal‐Atom Impact on the Self‐Assembly of Cup‐and‐Ball Metalloporphyrin–Fullerene Conjugates 下载免费PDF全文
Dr. Luis Moreira Joaquín Calbo Dr. Beatriz M. Illescas Dr. Juan Aragó Dr. Iwona Nierengarten Dr. Béatrice Delavaux‐Nicot Prof. Dr. Enrique Ortí Prof. Dr. Nazario Martín Prof. Dr. Jean‐François Nierengarten 《Angewandte Chemie (International ed. in English)》2015,54(4):1255-1260
A fullerene ammonium derivative has been combined with different metalloporphyrin–crown ether receptors to generate very stable supramolecules. The combination of fullerene–porphyrin and ammonium–crown ether interactions leads to a strong chelate effect as evidenced by a high effective molarity (3.16 M ). The different parameters influencing the stability of the supramolecular ensembles, in particular the nature of the metal in the porphyrin moiety, have been rationalized with the help of theoretical calculations thus providing new insights into fullerene–porphyrin interactions. 相似文献
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Dr. Nayarassery N. Adarsh Dr. Marinela M. Dîrtu Dr. Anil D. Naik Dr. Alexandre F. Léonard Dr. Nicolo Campagnol Dr. Koen Robeyns Dr. Johan Snauwaert Prof. Dr. Jan Fransaer Prof. Dr. Bao Lian Su Prof. Dr. Yann Garcia 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(11):4300-4307
A conformationally flexible triazole‐carboxylic acid ligand derived from an L ‐amino acid, namely, 4 H‐1,2,4‐triazol‐4‐yl‐acetic acid (αHGlytrz), has been exploited to synthesize a structurally diverse and functionally intriguing metal–organic framework with CuSiF6. The crystal structure reveals a novel single‐walled metal–organic nanotube (SWMONT), namely, {[Cu3(μ3‐OH)(H2O)3(Glytrz)3] ? SiF6 ? 8 H2O ? X}∞ ( 1 ), (where X=disordered lattice water molecules) having a pore size as large as zeolites. Compound 1 was synthesized as crystals, as powder, or as layers by precipitation/electrodeposition. Mercury intrusion porosimetry demonstrates the ability of this material to store metallic mercury, after a pressure treatment, contrary to previous literature examples. 相似文献
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Julia‐Maria Hübner Wilder Carrillo‐Cabrera Yurii Prots Matej Bobnar Ulrich Schwarz Yuri Grin 《Angewandte Chemie (International ed. in English)》2019,58(37):12914-12918
The silicon‐rich cage compound MgSi5 was obtained by high‐pressure high‐temperature synthesis. Initial crystal structure determination by electron diffraction tomography provided the basis for phase analyses in the process of synthesis optimization, finally facilitating the growth of single crystals suitable for X‐ray diffraction experiments. The crystal structure of MgSi5 (space group Cmme, Pearson notation oS24, a=4.4868(2) Å, b=10.1066(5) Å, and c=9.0753(4) Å) constitutes a new type of framework of four‐bonded silicon atoms forming Si15 cages enclosing the Mg atoms. Two types of smaller Si8 cages remain empty. The atomic interactions are characterized by two‐center two‐electron bonds within the silicon framework. In addition, there is evidence for multi‐center Mg?Si bonding in the large cavities of the framework and for lone‐pair‐like interactions in the smaller empty voids. 相似文献
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Component Selection in the Self‐Assembly of Palladium(II) Nanocages and Cage‐to‐Cage Transformations 下载免费PDF全文
Dipak Samanta Prof. Dr. Partha Sarathi Mukherjee 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(39):12483-12492
Dynamic supramolecular systems involving a tetratopic palladium(II) acceptor and three different pyridine‐ and imidazole‐based donors have been used for self‐selection by a synergistic effect of morphological information and coordination ability of ligands through specific coordination interactions. Three different cages were first synthesized by two‐component self‐assembly of individual donor and acceptor. When all four components were allowed to interact in a reaction mixture, only one out of three cages was isolated. The preferential binding affinity towards a particular partner was also established by transforming a non‐preferred cage into a preferred cage by interaction with the appropriate ligand. Computational studies further supported the fact that coordination interaction of imidazole moiety to PdII is enthalpically more preferred compared to pyridine, which drives the selection process. Analysis of crystal packing of both complexes indicated the presence of strong hydrogen bonds between nitrate and water molecules and also H‐bonded 3D networks of water. Both complexes exhibit promising proton conductivity (10?5 to ca. 10?3 S cm?1) at ambient temperature under a relative humidity of circa 98 % with low activation energy. 相似文献
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Dr. Valentina Abet Dr. Filip T. Szczypiński Dr. Marc A. Little Dr. Valentina Santolini Dr. Christopher D. Jones Dr. Robert Evans Dr. Craig Wilson Dr. Xiaofeng Wu Michael F. Thorne Dr. Michael J. Bennison Peng Cui Prof. Andrew I. Cooper Dr. Kim E. Jelfs Dr. Anna G. Slater 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(38):16898-16906
Many interesting target guest molecules have low symmetry, yet most methods for synthesising hosts result in highly symmetrical capsules. Methods of generating lower symmetry pores are thus required to maximise the binding affinity in host–guest complexes. Herein, we use mixtures of tetraaldehyde building blocks with cyclohexanediamine to access low-symmetry imine cages. Whether a low-energy cage is isolated can be correctly predicted from the thermodynamic preference observed in computational models. The stability of the observed structures depends on the geometrical match of the aldehyde building blocks. One bent aldehyde stands out as unable to assemble into high-symmetry cages-and the same aldehyde generates low-symmetry socially self-sorted cages when combined with a linear aldehyde. We exploit this finding to synthesise a family of low-symmetry cages containing heteroatoms, illustrating that pores of varying geometries and surface chemistries may be reliably accessed through computational prediction and self-sorting. 相似文献