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1.
Dr. Shin‐ichiro Kawano Takashi Hamazaki Atsushi Suzuki Kenshin Kurahashi Prof. Dr. Kentaro Tanaka 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(44):15674-15683
A new series of shape‐persistent imine‐bridged macrocycles were synthesized based on dynamic covalent chemistry. The macrocycles had an alternating sequence of dibenzothiophene and N,N′‐bis(salicylidene)‐ethylenediamine (salen) tethering branched alkyl chains. The macrocycles and tetranuclear metallomacrocycles bearing long and branched alkyl chains exhibited thermotropic columnar liquid‐crystalline phases over a wide temperature range and the metallomacrocycles greatly depended on the characteristics of the coordinated metal ions. The metal‐free macrocycle showed a liquid‐crystalline phase with a lamellar structure and poor birefringence. In sharp contrast, the macrocyclic Ni complex showed a columnar oblique liquid‐crystalline phase, whereas the Pd and Cu complexes showed columnar liquid‐crystalline phases with a lamellar structure. The macroscopic organization and thermal properties of the corresponding liquid‐crystalline metallomacrocycles were significantly dependent on the subtle structural differences among the planar macrocycles, which were revealed by single‐crystal X‐ray crystallographic analysis of the macrocycles with shorter alkyl chains. 相似文献
2.
Yoichi Habata Makoto Takeshita Yoji Fukuda Sadatoshi Akabori Jerald S. Bradshaw 《Journal of heterocyclic chemistry》2001,38(6):1323-1327
Dedicated to Professor Jerald S. Bradshaw Bis(2′‐hydroxyethyl) 2,6‐pyridinedicarboxylate (1) was prepared and the structure was characterized in solid (fourier transform‐ir and X‐ray analyses), in liquid (1H and 13C nmr titrations), and in the gas‐phase (fast atom bombardment (fab) and electron spray ionization (esi) ms). Two bis(2′‐hydroxyethyl) 2,6‐pyridinedicarboxylate molecules each with an included water molecule are bound together through hydrogen bonding to give a pseudo‐macrocycle in the solid state and in chloroform solution. The fab and esi mass spectra also suggested that ligand 1 forms a dimer in the gas‐phase. 相似文献
3.
《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2017,129(27):8047-8051
The synthesis, metalation, and redox properties of an acyclic bis(iminothienyl)methene L− are presented. This π‐conjugated anion displayed pronounced redox activity, undergoing facile one‐electron oxidation to the acyclic, metal‐free, neutral radical L . on reaction with FeBr2. In contrast, the reaction of L− with CuI formed the unique, neutral Cu2I2( L .) complex of a ligand‐centered radical, whereas reaction with the stronger oxidant AgBF4 formed the metal‐free radical dication L .2+. 相似文献
4.
Karolina Hurej Wojciech Stawski Prof. Lechosław Latos‐Grażyński Dr. Miłosz Pawlicki 《化学:亚洲杂志》2016,11(23):3329-3333
A meso‐N‐pyrrole porphyrin converts into a π‐extended porphyrin forming an indolizine‐3‐one motif. The indolizine‐3‐one frame opens a lactam subunit preserving a six‐membered, heterocyclic structure fused with the main macrocycle. The optical properties of formed derivatives follow the structural modifications giving the absorbance and emission eventually modulated by the NH‐centered modifications of the fused unit. 相似文献
5.
Takahiro Muraoka Tatsuya Shima Takashi Kajitani Norihisa Hoshino Estelle Morvan Axelle Grlard Erick J. Dufourc Takanori Fukushima Tomoyuki Akutagawa Kota Nabeya Kazushi Kinbara 《化学:亚洲杂志》2019,14(1):141-148
A polymesomorphic thermal phase‐transition of a macrocyclic amphiphile consisting of aromatic groups and oligoethylene glycol (OEG) chains is reported. The macrocyclic amphiphile exists in a highly‐ordered liquid crystal (LC) phase at room temperature. Upon heating, this macrocycle shows phase‐transition from columnar‐lamellar to nematic LC phases followed by crystallization before melting. Spectroscopic studies suggest that the thermally induced crystallization is triggered by a conformational change at the OEG chains. Interestingly, while the macrocycle returns to the columnar‐lamellar phase after cooling from the isotropic liquid, it retains the crystallinity after cooling from the thermally‐induced crystal. Thanks to this bistability, conductance switching was successfully demonstrated. A different macrocyclic amphiphile also shows an analogous phase‐transition behavior, suggesting that this molecular design is universal for developing switchable and memorizable materials, by means of hysteretic phase‐transition processes. 相似文献
6.
《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2017,129(39):11984-11987
The synthesis of a bowl‐shaped antiaromatic molecule was achieved through the deformation of a planar antiaromatic porphyrinic π‐conjugation system by insertion of palladium into the small cavity of a metal‐free norcorrole. The bowl‐to‐bowl inversion dynamics of the antiaromatic Pd‐coordinated norcorrole was determined by variable‐temperature 1H NMR spectroscopy. The metal‐free norcorrole was prepared from acid‐induced demetalation of a copper norcorrole, which was obtained from the intramolecular coupling of a bis(diiododipyrrin) copper complex with copper thiophenecarboxylate. 相似文献
7.
Dr. Lars Ratjen Dr. Ghislaine Vantomme Prof. Dr. Jean‐Marie Lehn 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(28):10070-10081
The displacement of molecular structures from their thermodynamically most stable state by imposition of various types of electronic and conformational constraints generates highly strained entities that tend to release the accumulated strain energy by undergoing either structural changes or chemical reactions. The latter case amounts to strain‐induced reactivity (SIR) that may enforce specific chemical transformations. A particular case concerns dynamic covalent chemistry which may present SIR, whereby reversible reactions are activated by coupling to a high‐energy state. We herewith describe such a dynamic covalent chemical (DCC) system involving the reversible imine formation reaction. It is based on the formation of strained macrocyclic bis‐imine metal complexes in which the macrocyclic ligand is in a high energy form enforced by the coordination of the metal cation. Subsequent demetallation generates a highly strained free macrocycle that releases its accumulated strain energy by hydrolysis and reassembly into a resting state. Specifically, the metal‐templated condensation of a dialdehyde with a linear diamine leads to a bis‐imine [1+1]‐macrocyclic complex in which the macrocyclic ligand is in a coordination‐enforced strained conformation. Removal of the metal cation by a competing ligand yields a highly reactive [1+1]‐macrocycle, which then undergoes hydrolysis to transient non‐cyclic aminoaldehyde species, which then recondense to a strain‐free [2+2]‐macrocyclic resting state. The process can be monitored by 1H NMR spectroscopy. Energy differences between different conformational states have been evaluated by Hartree–Fock (HF) computations. One may note that the stabilisation of high‐energy molecular forms by metal ion coordination followed by removal of the latter, offers a general procedure for producing out‐of‐equilibrium molecular states, the fate of which may then be examined, in particular when coupled to dynamic covalent chemical processes. 相似文献
8.
Ligand‐Unsupported Cuprophilicity in the Preparation of Dodecacopper(I) Complexes and Raman Studies
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N. V. Satyachand Harisomayajula Bo‐Han Wu Dr. Duan‐Yen Lu Ting‐Shen Kuo Prof. Dr. I‐Chia Chen Prof. Dr. Yi‐Chou Tsai 《Angewandte Chemie (International ed. in English)》2018,57(31):9925-9929
Synthesis and characterization of two dodecacopper(I) extended metal atom chains (EMAC) assembled by two hexadentate bis(pyridylamido)amidinate‐supported hexacopper(I) string complexes (monomers) via the ligand‐unsupported cuprophilicity are described. In addition to short unsupported Cu?Cu contacts, two hexacopper fragments in these two dodecacopper EMACs show a bent conformation based on X‐ray crystallography. Compared with their THF‐bound hexacopper(I) monomers and protonated ligands, these ligand‐unsupported cuprophilic interactions are shown to be weak by Raman spectroscopy. DFT calculations suggest the ligand‐unsupported cuprophilicity originate from weak attractive orbital interactions, and the strength is estimated to be 2.4 kcal mol?1. 相似文献
9.
Yoshihiko Nishimori Katsuhiko Kanaizuka Dr. Tomochika Kurita Toshiaki Nagatsu Yu Segawa Fumiyuki Toshimitsu Satoshi Muratsugu Dr. Mitsuya Utsuno Dr. Shoko Kume Dr. Masaki Murata Dr. Hiroshi Nishihara Prof. 《化学:亚洲杂志》2009,4(8):1361-1367
Electronic conductivity of molecular wires is a critical fundamental issue in molecular electronics. π‐Conjugated redox molecular wires with the superior long‐range electron‐transport ability could be constructed on a gold surface through the stepwise ligand–metal coordination method. The βd value, indicating the degree of decrease in the electron‐transfer rate constant with distance along the molecular wire between the electrode and the redox active species at the terminal of the wire, were 0.008–0.07 Å?1 and 0.002–0.004 Å?1 for molecular wires of bis(terpyridine)iron and bis(terpyridine)cobalt complex oligomers, respectively. The influences on βd by the chemical structure of molecular wires and the terminal redox units, temperature, electric field, and electrolyte concentration were clarified. The results indicate that facile sequential electron hopping between neighboring metal–complex units within the wire is responsible for the high electron‐transport ability. 相似文献
10.
Dissymmetrical U‐Shaped π‐Stacked Supramolecular Assemblies by Using a Dinuclear CuI Clip with Organophosphorus Ligands and Monotopic Fully π‐Conjugated Ligands
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Dr. Mehdi El Sayed Moussa Dr. Kevin Guillois Dr. Wenting Shen Prof. Régis Réau Dr. Jeanne Crassous Dr. Christophe Lescop 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(45):14853-14867
Reactions between the U‐shaped binuclear CuI complex A that bears short metal–metal distances and the cyano‐capped monotopic π‐conjugated ligands 1 – 5 that carry gradually bulkier polyaromatic terminal fragments lead to the formation of π‐stacked supramolecular assemblies 6 – 10 , respectively, in yields of 50–80 %. These derivatives have been characterized by multinuclear NMR spectroscopic analysis and X‐ray diffraction studies. Their solid‐state structures show the selective formation of U‐shaped supramolecular assemblies in which two monotopic π‐conjugated systems present large ( 6 , 7 , and 9 ) or medium ( 8 and 10 ) intramolecular π overlap, thus revealing π–π interactions. These assemblies self‐organize into head‐to‐tail π‐stacked dimers that in turn self‐assemble to afford infinite columnar π stacks. The nature, extent, and complexity of the intermolecular contacts within the head‐to‐tail π‐stacked dimer depend on the nature of the terminal polyaromatic fragment carried by the cyano‐capped monotopic ligand, but it does not alter the result of the self‐assembling process. These results demonstrate that the dinuclear molecular clip A that bears short metal–metal distances allows selective supramolecular assembly processes driven by the formation of intra‐ and intermolecular short π–π interactions in the resulting self‐assembled structures; thus, demonstrating that their shape is not only dictated by the symmetry of the building blocks. This approach opens perspectives toward the formation of extended π‐stacked columns based on dissymmetrical and functional π‐conjugated systems. 相似文献
11.
Two coordination polymers, [Cd(dpa)(L1)] ( 1 ) and [Cd(dpa)(L2)]·CH3CH2OH3 ( 2 ) (L1 = 2,6‐bis(1H‐benzimidazol‐2yl)‐pyridine, L2 = 2,2′‐(1,4‐butanediyl) bis (1H‐ benzimidazole) (L2), both of which contain helical chain subunits, were synthesized by the reaction of CdII salts and diphenic acid (H2dpa) with rigid, chelating and flexible, bridging auxiliary ligands, respectively. Compound 1 has a 1D helical chain structure, in which dpa2– as bridging ligand is responsible for the formation of the main framework and L1 as chelating ligand grafts on one side of the helical chain. This structure is further extended into a 3D supramolecular framework through two kinds of strong hydrogen bonding interactions. Compound 2 has a 2D structure, in which dpa2– bridges the CdII atoms into helical chains and L2 bridges the left‐ and right‐handed chains into a racemic layer with a [4,4] topology. 相似文献
12.
π‐Conjugated [2]Catenanes Based on Oligothiophenes and Phenanthrolines: Efficient Synthesis and Electronic Properties
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Dr. Xiaozhang Zhu Dr. Amaresh Mishra Prof. Dr. Jose‐Luis Segura Dr. Elena Mena‐Osteritz Prof. Dr. Peter Bäuerle 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(19):7193-7210
Novel π‐conjugated topologies based on oligothiophenes and phenanthroline have been assembled by combining their outstanding electronic and structural benefits with the specific properties of the topological structure. Macrocycles and catenanes are prepared by using an optimized protocol of transition metal‐templated macrocyclization followed by efficient Pd‐catalyzed cross‐coupling reaction steps. By using this method, [2]catenanes comprising two interlocked π‐conjugated macrocycles with different ring sizes have been synthesized. The structures of the [2]catenanes and corresponding macrocycles are confirmed by detailed 1H NMR spectroscopy and high resolution mass spectrometry. Single crystal X‐ray structural analysis of the quaterthiophene–diyne macrocycle affords important insight into the packing features and intermolecular interaction of the new systems. The fully conjugated interlocked [2]catenanes are fully characterized by spectroscopic and electrochemical measurements. 相似文献
13.
Dr. Shin‐ichiro Kawano Masahiro Kato Shinya Soumiya Dr. Masato Nakaya Prof. Dr. Jun Onoe Prof. Dr. Kentaro Tanaka 《Angewandte Chemie (International ed. in English)》2018,57(1):167-171
Columnar liquid crystals composed of a giant macrocyclic mesogen were prepared. The giant macrocyclic mesogen has a square hollow with a 2.5 nm diagonal, which was bounded by diindolo[3,2‐b:2′,3′‐h]carbazole (diindolocarbazole) moieties as the edges and bis(salicylidene)‐o‐phenylenediamine (salphen) moieties as the corners. The shape and size of the macrocycle were directly observed by scanning tunneling microscopy (STM). Each side of the bright square in the STM image corresponds to a diindolocarbazole moiety, and the length of the sides was consistent with the result of the single crystal analysis of diindolocarbazole. Finally, we successfully obtained a giant macrocycle with long and branched side chains, which exhibited a rectangular columnar LC phase over a wide temperature range. To the best of our knowledge, it contained the largest discrete inner space of any thermotropic columnar liquid crystal composed of macrocyclic mesogens. 相似文献
14.
《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2017,129(41):12717-12721
Red‐emissive fluorophores generally consist of large π‐extended systems and thus encounter the problem of serious fluorescence quenching in the solid state. A series of structurally simple compounds 2,5‐bis(alkylamino)terephthalates 1 a – c are reported that consist of a very small π‐system (only a single benzene) but display efficient red emission in crystals. Crystal 1 a having a molecular weight of only 252 g mol−1 shows red emission with the maximum of 620 nm and a fluorescence quantum yield of 0.40. The unique emission property of crystal 1 a is mainly because of the planarization of skeleton dominated by the strong intramolecular hydrogen bonds and the packing structure with negligible π–π interactions contributed by the mini π‐system. Moreover, besides efficient red emission, high crystallinity with co‐planar facets endows crystal 1 a with significant amplified spontaneous emission. 相似文献
15.
Control over the Self‐Assembly Modes of PtII Complexes by Alkyl Chain Variation: From Slipped to Parallel π‐Stacks
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Dr. Naveen Kumar Allampally Dr. María José Mayoral Dr. Sarayute Chansai Dr. María Cristina Lagunas Prof. Christopher Hardacre Dr. Vladimir Stepanenko Prof. Rodrigo Q. Albuquerque Prof. Dr. Gustavo Fernández 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(23):7810-7816
We report the self‐assembly of a new family of hydrophobic, bis(pyridyl) PtII complexes featuring an extended oligophenyleneethynylene‐derived π‐surface appended with six long (dodecyloxy ( 2 )) or short (methoxy ( 3 )) side groups. Complex 2 , containing dodecyloxy chains, forms fibrous assemblies with a slipped arrangement of the monomer units (dPt???Pt≈14 Å) in both nonpolar solvents and the solid state. Dispersion‐corrected PM6 calculations suggest that this organization is driven by cooperative π–π, C?H???Cl and π–Pt interactions, which is supported by EXAFS and 2D NMR spectroscopic analysis. In contrast, nearly parallel π‐stacks (dPt???Pt≈4.4 Å) stabilized by multiple π–π and C?H???Cl contacts are obtained in the crystalline state for 3 lacking long side chains, as shown by X‐ray analysis and PM6 calculations. Our results reveal not only the key role of alkyl chain length in controlling self‐assembly modes but also show the relevance of Pt‐bound chlorine ligands as new supramolecular synthons. 相似文献
16.
Dr. Totan Ghosh Dr. Natalia Fridman Dr. Monica Kosa Prof. Galia Maayan 《Angewandte Chemie (International ed. in English)》2018,57(26):7703-7708
Metal–ligand coordination is a key interaction in the self‐assembly of both biopolymers and synthetic oligomers. Although the binding of metal ions to synthetic proteins and peptides is known to yield high‐order structures, the self‐assembly of peptidomimetic molecules upon metal binding is still challenging. Herein we explore the self‐assembly of three peptoid trimers bearing a bipyridine ligand at their C‐terminus, a benzyl group at their N‐terminus, and a polar group (N‐ethyl‐R) in the middle position (R=OH, OCH3, or NH2) upon Cu2+ coordination. X‐ray diffraction analysis revealed unique, highly symmetric, dinuclear cyclic structure or aqua‐bridged dinuclear double‐stranded peptoid helicates, formed by the self‐assembly of two peptoid molecules with two Cu2+ ions. Only the macrocycle with the highest number of intermolecular hydrogen bonds is stable in solution, while the other two disassemble to their corresponding monometallic complexes. 相似文献
17.
Jingjuan Liu Yi Zhou Zhen Xie Yang Li Yunpeng Liu Jie Sun Yanhang Ma Osamu Terasaki Long Chen 《Angewandte Chemie (International ed. in English)》2020,59(3):1081-1086
A conjugated copper(II) catecholate based metal–organic framework (namely Cu‐DBC) was prepared using a D2‐symmetric redox‐active ligand in a copper bis(dihydroxy) coordination geometry. The π‐d conjugated framework exhibits typical semiconducting behavior with a high electrical conductivity of ca. 1.0 S m?1 at room temperature. Benefiting from the good electrical conductivity and the excellent redox reversibility of both ligand and copper centers, Cu‐DBC electrode features superior capacitor performances with gravimetric capacitance up to 479 F g?1 at a discharge rate of 0.2 A g?1. Moreover, the symmetric solid‐state supercapacitor of Cu‐DBC exhibits high areal (879 mF cm?2) and volumetric (22 F cm?3) capacitances, as well as good rate capability. These metrics are superior to most reported MOF‐based supercapacitors, demonstrating promising applications in energy‐storage devices. 相似文献
18.
Water‐Soluble Luminescent Cyclometalated Gold(III) Complexes with cis‐Chelating Bis(N‐Heterocyclic Carbene) Ligands: Synthesis and Photophysical Properties
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Faan‐Fung Hung Dr. Wai‐Pong To Dr. Jing‐Jing Zhang Dr. Chensheng Ma Prof. Dr. Wai‐Yeung Wong Prof. Dr. Chi‐Ming Che 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(28):8604-8614
A new class of cyclometalated AuIII complexes containing various bidentate C‐deprotonated C^N and cis‐chelating bis(N‐heterocyclic carbene) (bis‐NHC) ligands has been synthesized and characterized. These are the first examples of AuIII complexes supported by cis‐chelating bis‐NHC ligands. [Au(C^N)(bis‐NHC)] complexes display emission in solutions under degassed condition at room temperature with emission maxima (λmax) at 498–633 nm and emission quantum yields of up to 10.1 %. The emissions are assigned to triplet intraligand (IL) π→π* transitions of C^N ligands. The AuIII complex containing a C^N (C‐deprotonated naphthalene‐substituted quinoline) ligand with extended π‐conjugation exhibits prompt fluorescence and phosphorescence of comparable intensity with λmax at 454 and 611 nm respectively. With sulfonate‐functionalized bis‐NHC ligand, four water‐soluble luminescent AuIII complexes, including those displaying both fluorescence and phosphorescence, were prepared. They show similar photophysical properties in water when compared with their counterparts in acetonitrile. The long phosphorescence lifetime of the water‐soluble AuIII complex with C‐deprotonated naphthalene‐substituted quinoline ligand renders it to function as ratiometric sensor for oxygen. Inhibitory activity of one of these water‐soluble AuIII complexes towards deubiquitinase (DUB) UCHL3 has been investigated; this complex also displayed a significant inhibitory activity with IC50 value of 0.15 μM . 相似文献
19.
《Acta Crystallographica. Section C, Structural Chemistry》2018,74(2):171-176
A dimerized 1,3‐diazaazulene derivative, namely 1,4‐bis(1,3‐diazaazulen‐2‐yl)benzene [or 2,2′‐(1,4‐phenylene)bis(1,3‐diazaazulene)], C22H14N4, (I), has been synthesized successfully through the condensation reaction between 2‐methoxytropone and benzene‐1,4‐dicarboximidamide hydrochloride, and was characterized by 1H NMR and 13C NMR spectroscopies, and ESI–MS. X‐ray diffraction analysis reveals that (I) has a nearly planar structure with good π‐electron delocalization, indicating that it might serve as a π building block. The crystal belongs to the monoclinic system. One‐dimensional chains were formed along the a axis through π–π interactions and adjacent chains are stabilized by C—H…N interactions, forming a three‐dimensional architecture. The solid emission of (I) in the crystalline form exhibited a 170 nm red shift compared with that in the solution state. The observed optical bandgap for (I) is 3.22 eV and a cyclic voltammetry experiment confirmed the energy levels of the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO). The calculated bandgap for (I) is 3.37 eV, which is very close to the experimental result. In addition, the polarizability and hyperpolarizability of (I) were appraised for its further application in second‐order nonlinear optical materials. 相似文献
20.
Lijian Zhong Long Chen Wen Feng Shuliang Zou Yuanyou Yang Ning Liu Lihua Yuan 《Journal of inclusion phenomena and macrocyclic chemistry》2012,72(3-4):367-373
The extraction of three shape-persistent aromatic oligoamide macrocycles (cycloaramides) bearing either apolar or polar side chains at the periphery of the rings has been investigated towards some representative lanthanide and actinide ions, and alkali metal ions. The results from the liquid–liquid extraction of lanthanide and thorium ions from aqueous solutions into dichloromethane revealed remarkably high extractability of up to 99% and selectivity over alkali metal cations. The stoichiometry of the complex formed between the macrocycle and Eu3+ or Th4+ was determined to be 1:1. 相似文献