共查询到20条相似文献,搜索用时 0 毫秒
1.
2.
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
3.
Hatem M. Titi Dr. Ranjan Patra Prof. Israel Goldberg 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(44):14941-14949
This study targets the construction of porphyrin assemblies directed by halogen bonds, by utilizing a series of purposely synthesized Sn(axial ligand)2–(5,10,15,20‐tetraarylporphyrin) [Sn(L)2‐TArP] complexes as building units. The porphyrin moiety and the axial ligands in these compounds contain different combinations of complimentary molecular recognition functions. The former bears p‐iodophenyl, p‐bromophenyl, 4′‐pyridyl, or 3′‐pyridyl substituents at the meso positions of the porphyrin ring. The latter comprises either a carboxylate or hydroxy anchor for attachment to the porphyrin‐inserted tin ion and a pyridyl‐, benzotriazole‐, or halophenyl‐type aromatic residue as the potential binding site. The various complexes were structurally analyzed by single‐crystal X‐ray diffraction, accompanied by computational modeling evaluations. Halogen‐bonding interactions between the lateral aryl substituents of one unit of the porphyrin complex and the axial ligands of neighboring moieties was successfully expressed in several of the resulting samples. Their occurrence is affected by structural (for example, specific geometry of the six‐coordinate complexes) and electronic effects (for example, charge densities and electrostatic potentials). The shortest intermolecular I???N halogen‐bonding distance of 2.991 Å was observed between iodophenyl (porphyrin) and benzotriazole (axial ligand) moieties. Manifestation of halogen bonds in these relatively bulky compounds without further activation of the halophenyl donor groups by electron‐withdrawing substituents is particularly remarkable. 相似文献
4.
Self‐Assembly of Five 8‐Hydroxyquinolinate‐Based Complexes: Tunable Core,Supramolecular Structure,and Photoluminescence Properties 下载免费PDF全文
Prof. Dr. Guozan Yuan Weilong Shan Xuelong Qiao Li Ma Prof. Dr. Yanping Huo 《化学:亚洲杂志》2014,9(7):1913-1921
Five new ZnII complexes, namely [Zn3(L)6] ( 1 ), [Zn2(Cl)2(L)2(py)2] ( 2 ), [Zn2(Br)2(L)2(py)2] ( 3 ), [Zn(L)2(py)] ( 4 ), and [Zn2(OAc)2(L)2(py)2] ( 5 ), were prepared by the solvothermal reaction of ZnX2 (X?=Cl?, Br?, F?, and OAc?) salts with a 8‐hydroxyquinolinate ligand (HL) that contained a trifluorophenyl group. All of the complexes were characterized by elemental analysis, IR spectroscopy, and powder and single‐crystal X‐ray crystallography. The building blocks exhibited unprecedented structural diversification and their self‐assembly afforded one mononuclear, three binuclear, and one trinuclear ZnII structures in response to different anions and solvent systems. Complexes 1 – 5 featured four types of supramolecular network controlled by non‐covalent interactions, such as π???π‐stacking, C? H???π, hydrogen‐bonding, and halogen‐related interactions. Investigation of their photoluminescence properties exhibited disparate emission wavelengths, lifetimes, and quantum yields in the solid state. 相似文献
5.
Bobby Happ Dr. Georges M. Pavlov Esra Altuntas Christian Friebe Dr. Martin D. Hager Dr. Andreas Winter Dr. Helmar Görls Dr. Wolfgang Günther Prof. Dr. Ulrich S. Schubert 《化学:亚洲杂志》2011,6(3):873-880
Two 3,6‐bis(R‐1H‐1,2,3‐triazol‐4‐yl)pyridazines (R=mesityl, monodisperse (CH2 CH2O)12CH3) were synthesized by the copper(I)‐catalyzed azide–alkyne cycloaddition and self‐assembled with tetrakis(acetonitrile)copper(I) hexafluorophosphate and silver(I) hexafluoroantimonate in dichloromethane. The obtained copper(I) complexes were characterized in detail by time‐dependent 1D [1H, 13C] and 2D [1H‐NOESY] NMR spectroscopy, elemental analysis, high‐resolution ESI‐TOF mass spectrometry, and analytical ultracentrifugation. The latter characterization methods, as well as the comparison to analog 3,6‐di(2‐pyridyl)pyridazine (dppn) systems and their corresponding copper(I) and silver(I) complexes indicated that the herein described 3,6‐bis(1H‐1,2,3‐triazol‐4‐yl)pyridazine ligands form [2×2] supramolecular grids. However, in the case of the 3,6‐bis(1‐mesityl‐1H‐1,2,3‐triazol‐4‐yl)pyridazine ligand, the resultant red‐colored copper(I) complex turned out to be metastable in an acetone solution. This behavior in solution was studied by NMR spectroscopy, and it led to the conclusion that the copper(I) complex transforms irreversibly into at least one different metal complex species. 相似文献
6.
Dr. Mingwei Zhao Dr. Yurong Zhao Prof. Liqiang Zheng Prof. Caili Dai 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(3):1076-1081
Highly ordered supramolecular microfibers were constructed through a simple ionic self‐assembly strategy from complexes of the N‐tetradecyl‐N‐methylpyrrolidinium bromide (C14MPB) surface‐active ionic liquid and the small methyl orange (MO) dye molecule, with the aid of patent blue VF sodium salt. By using scanning electron microscopy and polarized optical microscopy, the width of these self‐assembled microfibers is observed to be about 1 to 5 μm and their length is from tens of micrometers to almost a millimeter. The 1H NMR spectra of the microfibers indicates that the supramolecular complexes are composed of C14MPB and MO in equal molar ratio. The electrostatic, hydrophobic, and π–π stacking interactions are regarded as the main driving forces for the formation of microfibers. Furthermore, through characterization by using confocal fluorescence microscopy, the microfibers were observed to show strong fluorescent properties and may find potential applications in many fields. 相似文献
7.
8.
9.
10.
11.
DNA‐Grafted Supramolecular Polymers: Helical Ribbon Structures Formed by Self‐Assembly of Pyrene–DNA Chimeric Oligomers 下载免费PDF全文
Yuliia Vyborna Mykhailo Vybornyi Dr. Alexander V. Rudnev Prof. Dr. Robert Häner 《Angewandte Chemie (International ed. in English)》2015,54(27):7934-7938
The controlled arraying of DNA strands on adaptive polymeric platforms remains a challenge. Here, the noncovalent synthesis of DNA‐grafted supramolecular polymers from short chimeric oligomers is presented. The oligomers are composed of an oligopyrenotide strand attached to the 5′‐end of an oligodeoxynucleotide. The supramolecular polymerization of these oligomers in an aqueous medium leads to the formation of one‐dimensional (1D) helical ribbon structures. Atomic force and transmission electron microscopy show rod‐like polymers of several hundred nanometers in length. DNA‐grafted polymers of the type described herein will serve as models for the development of structurally and functionally diverse supramolecular platforms with applications in materials science and diagnostics. 相似文献
12.
A Simple and Highly Effective Ligand System for the Copper(I)‐Mediated Assembly of Rotaxanes 下载免费PDF全文
Dr. Christopher J. Campbell Prof. David A. Leigh Dr. Inigo J. Vitorica‐Yrezabal Steffen L. Woltering 《Angewandte Chemie (International ed. in English)》2014,53(50):13771-13774
A [2]rotaxane was produced through the assembly of a picolinaldehyde, an amine, and a bipyridine macrocycle around a CuI template by imine bond formation in close‐to‐quantitative yield. An analogous [3]rotaxane is obtained in excellent yield by replacing the amine with a diamine, thus showing the suitability of the system for the construction of higher order interlocked structures. The rotaxanes are formed within a few minutes simply through mixing the components in solution at room temperature and they can be isolated through removal of the solvent or precipitation. 相似文献
13.
Dr. Partha S. Ghosh Prof. Dr. Andrew D. Hamilton 《Chemistry (Weinheim an der Bergstrasse, Germany)》2012,18(8):2361-2365
We report here the noncovalent synthesis of thermosensitive dendrimers. Short oligoguanosine strands were linked to the focal point of a dendron by using “click chemistry”, and quadruplex formation was used to drive the self‐assembly process in the presence of metal ions. The dynamic nature of these noncovalent assemblies can be exploited to create combinatorial libraries of dendrimers as demonstrated by the co‐assembly of two components. These supramolecular dendrimers showed thermoresponsive behavior that can be tuned by varying the templating cations or the number of guanines in the oligonucleotide strand. 相似文献
14.
Two novel supramolecular complexes, [Cu(bopapa)(mal)]·H2O·CH3OH (1) and {[Cu(bopapap)](Hmal)2}·2H2O (2) [bpapa = bis-[6-(2-pyridylamino)pyrid-2-yl]amine, bpapap = 2,6-bis-[6-(pyrid-2-ylamino)pyrid-2-ylamino]- pyridine, mal=maleate dianion] were rationally designed and synthesized based on flexible multidentate ligands and copper(Ⅱ) maleate. Complexes 1 and 2 were all characterized by elemental analysis, spectroscopic techniques, thermal analysis and single crystal X-ray diffraction analysis. Complex 1 is of an infinite 3-D supramolecular framework constructed by 2-D sheets to contain 1-D helical chains formed by intermolecular hydrogen bond inter- actions between the non-coordinated oxygen atoms from maleate and nitrogen atoms from amino groups of bpapa. Complex 2 also takes a 3-D supramolecular structure, which is built from 2-D rhombic sheets produced by sequential dimer units. Interestingly, three pairs of symmetrical hydrogen bonds generate these dimer units. 相似文献
15.
16.
17.
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
18.
Dr. Cécilia Ménard‐Moyon V. Venkatesh Dr. K. Vijaya Krishna Dr. Fanny Bonachera Prof. Sandeep Verma Dr. Alberto Bianco 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(33):11681-11686
In the context of designing novel amino acid nanostructures, the capacity of tyrosine alone to form well‐ordered structures under different conditions was explored. It was observed that Tyr can self‐assemble into well‐defined morphologies when deposited onto surfaces for transmission electron microscopy, atomic force microscopy, and scanning electron microscopy. The influence of various parameters that can modulate the self‐assembly process, including concentration of the amino acid, aging time, and solvent, was studied. Different supramolecular architectures, including nanoribbons, branched structures, and fern‐like arrangements were also observed. 相似文献
19.
20.
Hierarchical Self‐Assembly of Supramolecular Hydrophobic Metallacycles into Ordered Nanostructures 下载免费PDF全文
Jing Zhang Dr. Riccardo Marega Li‐Jun Chen Nai‐Wei Wu Xing‐Dong Xu Prof. Dr. David C. Muddiman Prof. Dr. Davide Bonifazi Prof. Dr. Hai‐Bo Yang 《化学:亚洲杂志》2014,9(10):2928-2936
We describe herein the hierarchical self‐assembly of discrete supramolecular metallacycles into ordered fibers or spherical particles through multiple noncovalent interactions. A new series of well‐defined metallacycles decorated with long alkyl chains were obtained through metal–ligand interactions, which were capable of aggregating into ordered fibroid or spherical nanostructures on the surface, mostly driven by hydrophobic interactions. In‐depth studies indicated that the morphology diversity was originated from the structural information encoded in the metallacycles, including the number of alkyl chains and their spatial orientation. Interestingly, the morphology of the metallacycle aggregates could be tuned by changing the solvent polarity. These findings are of special significance since they provide a simple yet highly controllable approach to prepare ordered and tunable nanostructures from small building blocks by means of hierarchical self‐assembly. 相似文献