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1.
《中国化学》2018,36(7):594-598
Using coinage metal (Cu(II), Ag(I)) hinges, two sets of heterometallic molecular capsules with analogous open‐ended cavities were prepared based on the half‐sandwich rhodium fragments. In the case of [Rh4Cu4] cages, up to six‐fold‐stacked host‐guest structures were formed by varying the cavity's dimensions. Moreover, the series of capsules were demonstrated to self‐fine‐tune to form multi‐heteroguest arrays via favourable donor‐acceptor π interactions and Ag‐π interactions, as evidenced from single‐crystal X‐ray analysis. 相似文献
2.
Qian-Feng Zhang Richard D. Adams Dieter Fenske 《Journal of inclusion phenomena and macrocyclic chemistry》2005,53(3):275-279
The self-assemblies of two pyrogallol[4]arenes held together by 48 intermolecular hydrogen bonds stably associate in the form of spherical hexameric capsules. The molecular structures of two hexameric capsules with large interior space were analyzed by single crystal X-ray crystallography. 相似文献
3.
Qian-Feng Zhang Richard D. Adams Dieter Fenske 《Journal of inclusion phenomena and macrocyclic chemistry》2005,53(3-4):275-279
The self-assemblies of two pyrogallol[4]arenes held together by 48 intermolecular hydrogen bonds stably associate in the form of spherical hexameric capsules. The molecular structures of two hexameric capsules with large interior space were analyzed by single crystal X-ray crystallography. 相似文献
4.
Rebecca L. Greenaway Valentina Santolini Angeles Pulido Marc A. Little Ben M. Alston Michael E. Briggs Graeme M. Day Andrew I. Cooper Kim E. Jelfs 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(45):16421-16427
We describe the a priori computational prediction and realization of multi‐component cage pots, starting with molecular predictions based on candidate precursors through to crystal structure prediction and synthesis using robotic screening. The molecules were formed by the social self‐sorting of a tri‐topic aldehyde with both a tri‐topic amine and di‐topic amine, without using orthogonal reactivity or precursors of the same topicity. Crystal structure prediction suggested a rich polymorphic landscape, where there was an overall preference for chiral recognition to form heterochiral rather than homochiral packings, with heterochiral pairs being more likely to pack window‐to‐window to form two‐component capsules. These crystal packing preferences were then observed in experimental crystal structures. 相似文献
5.
This paper elucidates the means to control precisely the morphology of electrospun liquid crystal/polymer fibers formed by phase separation. The relative humidity, solution parameters (concentration, solvent), and the process parameter (feed rate) were varied systematically. We show that the morphology of the phase‐separated liquid crystal can be continuously tuned from capsules to uniform fibers with systematic formation of beads‐on‐a‐string structured fibers in the intermediate ranges. In all cases, the polymer forms a sheath around a liquid‐crystal (LC) core. The width of the polymer sheath and the diameter of the LC core increase with increasing feed rates. This is similar to the results obtained by coaxial electrospinning. Because these fibers retain the responsive properties of liquid crystals and because of their large surface area, they have potential applications as thermo‐, chemo‐, and biosensors. Because the size and shape of the liquid‐crystal domains will have a profound effect on the performance of the fibers, our ability to precisely control morphology will be crucial in developing these applications. 相似文献
6.
Enzymatic degradation behavior of a lamella of single crystals of poly(R)‐3‐hydroxybutyrate (P(3HB)) with an extracellular polyhydroxybutyrate (PHB) depolymerase purified from Alcaligenes faecalis T1 has been investigated by atomic force microscopy (AFM) in order to obtain further information for the chain packing state of P(3HB) in a lamellar single crystal. Two kinds of P(3HB) single crystals with different molecular weights, denoted respectively as H‐ and L‐P(3HB) for high and low molecular weights, respectively, were prepared. The enzymatic treatment was conducted for P(3HB) single crystals adsorbed on a surface of highly ordered pyrolytic graphite. The enzymatic degradation of both P(3HB) single crystals generates several crevices crosswise across the crystal at an early stage. Subsequently, the enzymatic degradation yields numbers of cracks lengthwise along the crystal. In addition to these common features, the interval between cracks crosswise across a lamella in H‐P(3HB) single crystal is longer than that in L‐P(3HB) single crystal, and each crack has V‐shaped and rectangular shaped morphology for H‐ and L‐P(3HB) single crystals, respectively. Based on these results, it is concluded that a lamella of P(3HB) single crystal has straight degradation pathways, that may correspond to a switchboard region, along the long axis of the crystal, independent of molecular weight of P(3HB) samples, and that a H‐P(3HB) single crystal has broader degradation pathways with longer intervals crosswise across the crystal than a L‐P(3HB) single crystal. 相似文献
7.
Formation of a Syndiotactic Organic Polymer Inside a MOF by a [2+2] Photo‐Polymerization Reaction
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Dr. In‐Hyeok Park Dr. Raghavender Medishetty Hyeong‐Hwan Lee Caroline Evania Mulijanto Hong Sheng Quah Prof. Shim Sung Lee Prof. Jagadese J. Vittal 《Angewandte Chemie (International ed. in English)》2015,54(25):7313-7317
Getting suitable crystals for single‐crystal X‐ray crystallographic analysis still remains an art. Obtaining single crystals of metal–organic frameworks (MOFs) containing organic polymers poses even greater challenges. Here we demonstrate the formation of a syndiotactic organic polymer ligand inside a MOF by quantitative [2+2] photopolymerization reaction in a single‐crystal‐to‐single‐crystal manner. The spacer ligands with trans,trans,trans‐conformation in the pillared‐layer MOF with guest water molecules in the channels, undergo pedal motion to trans,cis,trans‐conformation prior to [2+2] photo‐cycloaddition reaction and yield single crystals of MOF containing two‐dimensional coordination polymers fused with the organic polymer ligands. We also show that the organic polymer in the single crystals can be depolymerized reversibly by cleaving the cyclobutane rings upon heating. These MOFs also show interesting photoluminescent properties and sensing of small organic molecules. 相似文献
8.
In‐Hyeok Park Anjana Chanthapally Dr. Zhenjie Zhang Prof. Dr. Shim Sung Lee Prof. Dr. Michael J. Zaworotko Prof. Dr. Jagadese J. Vittal 《Angewandte Chemie (International ed. in English)》2014,53(2):414-419
Organic polymers are usually amorphous or possess very low crystallinity. The metal complexes of organic polymeric ligands are also difficult to crystallize by traditional methods because of their poor solubilities and their 3D structures can not be determined by single‐crystal X‐ray crystallography owing to a lack of single crystals. Herein, we report the crystal structure of a 1D ZnII coordination polymer fused with an organic polymer ligand made in situ by a [2+2] cycloaddition reaction of a six‐fold interpenetrated metal–organic framework. It is also shown that this organic polymer ligand can be depolymerized in a single‐crystal‐to‐single‐crystal (SCSC) fashion by heating. This strategy could potentially be extended to make a range of monocrystalline metal organopolymeric complexes and metal–organic organopolymeric hybrid materials. Such monocrystalline metal complexes of organic polymers have hitherto been inaccessible for materials researchers. 相似文献
9.
In Situ Observation of Thiol Michael Addition to a Reversible Covalent Drug in a Crystalline Sponge
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Dr. Vincent Duplan Dr. Manabu Hoshino Dr. Wei Li Prof. Dr. Tadashi Honda Prof. Dr. Makoto Fujita 《Angewandte Chemie (International ed. in English)》2016,55(16):4919-4923
A reversible Michael addition reaction between thiol nucleophiles and cyanoenones has been previously postulated to be the mechanism‐of‐action of a new family of reversible covalent drugs. However, the hypothetical Michael adducts in this mechanism have only been detected by spectroscopic methods in solution. Herein, the crystallographic observation of reversible Michael addition with a potent cyanoenone drug candidate by means of the crystalline‐sponge method is reported. After inclusion of the cyanoenone substrate, the sponge crystal was treated with a thiol solution. Subsequent crystallographic analysis confirmed the single‐crystal‐to‐single‐crystal transformation of the substrate into the impermanent Michael adduct. 相似文献
10.
Dr. Joice Thomas Dr. Liliana Dobrzańska Prof. Luc Van Meervelt Prof. Mario Alfredo Quevedo Prof. Krzysztof Woźniak Marcin Stachowicz Prof. Mario Smet Prof. Wouter Maes Prof. Wim Dehaen 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(3):979-987
A synthetic route towards homodiselenacalix[4]arene macrocycles is presented, based on the dynamic covalent chemistry of diselenides. The calixarene inner rim is decorated with either alkoxy or tert‐butyl ester groups. Single‐crystal X‐ray analysis of two THF solvates with methoxy and ethoxy substituents reveals the high similarity of their molecular structures and alterations on the supramolecular level. In both crystal structures, solvent channels are present and differ in both shape and capacity. Furthermore, the methoxy‐substituted macrocycle undergoes a single‐crystal‐to‐single‐crystal transformation during which the molecular structure changes its conformation from 1,3‐alternate (loaded with THF/water) to 1,2‐alternate (apohost form). Molecular modelling techniques were applied to explore the conformational and energetic behaviour of the macrocycles. 相似文献
11.
Qi Yu Mingmin Li Jia Gao Peixin Xu Qizhe Chen Dong Xing Jie Yan Michael J. Zaworotko Jun Xu Yao Chen Peng Cheng Zhenjie Zhang 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(51):18807-18813
Preparation of large single crystals of linear polymers for X‐ray analysis is very challenging. Herein, we employ a coordination‐driven self‐assembly strategy to secure the appropriate head‐to‐tail alignment of anthracene moieties, and for the first time obtained large‐sized Pt‐based linear polymer crystals through a [4+4] cycloaddition of anthracene in a single‐crystal to single‐crystal fashion. Using X‐ray diffraction to determine the polymer crystal structure, we found that both the polymerisation and depolymerisation steps proceed via a stable intermediate. Taking advantage of the temperature‐dependent slow depolymerization, the Pt‐based linear polymer showed potential as a sustained release anticancer drug platform. Utilizing the reversible contraction effect of unit‐cell volume upon irradiation or heating, the stimuli‐responsive crystals were hybridized with polyvinylidene fluoride to obtain a “smart material” with outstanding photoactuator performance. 相似文献
12.
Solid‐State Conformational Flexibility at Work: Zipping and Unzipping within a Cyclic Peptoid Single Crystal
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Dr. Alessandra Meli Dr. Eleonora Macedi Prof. Francesco De Riccardis Dr. Vincent J. Smith Prof. Leonard J. Barbour Prof. Irene Izzo Dr. Consiglia Tedesco 《Angewandte Chemie (International ed. in English)》2016,55(15):4679-4682
A peptidomimetic compound undergoes a reversible single‐crystal‐to‐single‐crystal transformation upon guest release/uptake with the transformation involving a drastic conformational change. The extensive and reversible alteration in the solid state is connected to the formation of an unprecedented “CH–π zipper” which can reversibly open and close (through the formation of CH–π interactions), thus allowing for guest sensing. 相似文献
13.
《Angewandte Chemie (International ed. in English)》2017,56(4):1152-1157
Supramolecular capsules were assembled by neutral halogen bonding (XB) and studied in the solid state, in solution, and in the gas phase. The geometry of the highly organized capsules is shown by an X‐ray crystal structure which features the assembly of two XB hemispheres, geometrically rigidified by H‐bonding to eight MeOH molecules and encapsulation of two benzene guests. To enhance capsular association strength, tuning the XB donor is more efficient than tuning the XB acceptor, due to desolvation penalties in protic solvents, as shown for a tetraquinuclidine XB acceptor hemisphere. With a tetra(iodoethynyl) XB donor and a tetralutidine XB acceptor, the association in deuterated benzene/acetone/methanol 70:30:1 at 283 K reaches K a=(2.11±0.39)×105 m −1 (ΔG =−6.9±0.1 kcal mol−1). The stability of the XB capsules in the gas phase was confirmed by electrospray ionization mass spectrometry (ESI‐MS). A new guest binding site was uncovered within the elongated iodoethynyl capsule. 相似文献
14.
Toshiyuki Sasaki Shunichi Sakamoto Yuichi Takasaki Satoshi Takamizawa 《Angewandte Chemie (International ed. in English)》2020,59(11):4340-4343
Mechanical twinning changes atomic, molecular, and crystal orientations along with directions of the anisotropic properties of the crystalline materials while maintaining single crystallinity in each domain. However, such deformability has been less studied in brittle organic crystals despite their remarkable anisotropic functions. Herein we demonstrate a direction‐dependent mechanical twinning that shows superelasticity in one direction and ferroelasticity in two other directions in a single crystal of 1,3‐bis(4‐methoxyphenyl)urea. The crystal can undergo stepwise twinning and ferroelastically forms various shapes with multiple domains oriented in different directions, thereby affording a crystal that shows superelasticity in multiple directions. This adaptability and shape recoverability in a ferroelastic and superelastic single crystal under ambient conditions are of great importance in future applications of organic crystals as mechanical materials, such as in soft robotics. 相似文献
15.
Sun‐Min Jung Dongwook Kim Dongbin Shin Dr. Javeed Mahmood Prof. Dr. Noejung Park Prof. Dr. Myoung Soo Lah Prof. Dr. Hu Young Jeong Prof. Dr. Jong‐Beom Baek 《Angewandte Chemie (International ed. in English)》2016,55(26):7413-7417
Solid‐state reactions have been rapidly gaining popularity in organic chemistry owing to their simplicity, efficiency, and selectivity compared to liquid‐phase reactions. Herein, we describe the formation of superstructures through the solid‐state reaction of an organic single‐crystal. The superstructure of 5,5′,5′′‐(1,3,5‐triazine‐2,4,6‐triyl)triisophthalonitrile (TIPN) can be formed by cyclotrimerization of 1,3,5‐tricyanobenzene (TCB) single crystals. The TIPN superstructure was confirmed by single crystal X‐ray diffraction and visualized by transmission electron microscopy. The superstructure has hexagonally packed 1‐dimensional (1D) channels along the crystal axis. Furthermore, the superstructure arises from interdigitated nitrile interactions in the crystal lattice, and thus has electron‐beam tolerance and very high thermal stability. 相似文献
16.
Organic semiconducting single crystals are perfect for both fundamental and application‐oriented research due to the advantages of free grain boundaries, few defects, and minimal traps and impurities, as well as their low‐temperature processability, high flexibility, and low cost. Carrier mobilities of greater than 10 cm2 V?1 s?1 in some organic single crystals indicate a promising application in electronic devices. The progress made, including the molecular structures and fabrication technologies of organic single crystals, is introduced and organic single‐crystal electronic devices, including field‐effect transistors, phototransistors, p‐n heterojunctions, and circuits, are summarized. Organic two‐dimensional single crystals, cocrystals, and large single crystals, together with some potential applications, are introduced. A state‐of‐the‐art overview of organic single‐crystal electronics, with their challenges and prospects, is also provided. 相似文献
17.
Dr. Jiangping Xu Dr. Jun Li Yi Yang Dr. Ke Wang Nan Xu Dr. Jingyi Li Dr. Ruijing Liang Prof. Lei Shen Prof. Xiaolin Xie Prof. Juan Tao Prof. Jintao Zhu 《Angewandte Chemie (International ed. in English)》2016,55(47):14633-14637
Although high‐boiling non‐solvent induced macrophase separation in emulsion droplets has been widely applied for the fabrication of polymeric capsules, precise control of their structures remains a great challenge. Herein, block copolymer capsules with tunable shell structures were fabricated by employing a non‐solvent as a liquid template in emulsion droplets. The properties of the non‐solvents dictate the phase separation sequence in the droplets and the capsule formation mechanism. Two different pathways for capsule formation were observed, and could be applied to predict the shell structure. The structured capsules could be transformed into mesoporous capsules, which demonstrated an intriguing structure‐dependent release behavior. Capsules with spherical shell structures displayed the best permeability, while those with lamellar shell structures showed the slowest release, but with a stepwise profile. After loading with an anticancer drug, different capsules induced different apoptosis ratios in cancer cell studies. 相似文献
18.
Vignesh Athiyarath Kana M. Sureshan 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(2):622-627
Two cases of spontaneous evolution of monomers to linear polymers having novel cross‐laminated topology are reported. We synthesized two peptide monomers N3‐Gly‐Gly‐NH‐CH2‐CCH and N3‐Gly‐Gly‐Gly‐CH2‐CCH and solved their crystal structures by single‐crystal X‐ray diffraction. They adopt H‐bonded crisscrossed layered packing in their crystals such that: (a) the monomers are aligned head‐to‐tail in 1D‐chain‐like arrays and parallel arrangement of such arrays forms a layer; (b) the proximally placed azide and alkyne motifs are in an orientation apt for their regiospecific cycloaddition; (c) each monomer having x peptide bonds is H‐bonded with 2x monomers disposed in intersecting arrangement, which pre‐organize 1D‐chain‐like arrays in adjacent layers in perpendicular orientation. These crystals underwent spontaneous single‐crystal‐to‐single‐crystal (SCSC) polymerization via azide–alkyne cycloaddition reaction to form triazolyl‐polyglycines, at room temperature. The crisscrossed arrangement of monomers in adjacent layers ensured the formation of cross‐laminated polymers. 相似文献
19.
Fabian M. Schuett Derek Esau K. Liam Varvaris Shelly Gelman Jonas Bjrk Johanna Rosen Gregory Jerkiewicz Timo Jacob 《Angewandte Chemie (International ed. in English)》2020,59(32):13246-13252
The growth of noble‐metal single crystals via the flame fusion method was developed in the 1980s. Since then, there have been no major advancements to the technique until the recent development of the controlled‐atmosphere flame fusion (CAFF) method to grow non‐noble Ni single crystals. Herein, we demonstrate the generality of this method with the first preparation of fcc Cu as well as the first hcp and bcc single crystals of Co and Fe, respectively. The high quality of the single crystals was verified using scanning electron microscopy and Laue X‐ray backscattering. Based on Wulff constructions, the equilibrium shapes of the single‐crystal particles were studied, confirming the symmetry of the fcc, hcp, and bcc single‐crystal lattices. The low cost of the CAFF method makes all kinds of high‐quality non‐noble single crystals independent of their lattice accessible for use in electrocatalysis, electrochemistry, surface science, and materials science. 相似文献
20.
Zhihui Chen Gianpiero Gallo Vaishali A. Sawant Tianxiang Zhang Menglong Zhu Liangliang Liang Anjana Chanthapally Geetha Bolla Hong Sheng Quah Xiaogang Liu Kian Ping Loh Robert E. Dinnebier Qing‐Hua Xu Jagadese J. Vittal 《Angewandte Chemie (International ed. in English)》2020,59(2):833-838
Interpenetration in metal–organic frameworks (MOFs) is an intriguing phenomenon with significant impacts on their properties, and functional applications. Herein, we show that a 7‐fold interpenetrated MOF ( 1 ) is transformed into an 8‐fold interpenetrated MOF by the loss of DMF in a single‐crystal‐to‐single‐crystal manner. This is accompanied by a giant enhancement of the second harmonic generation (SHG ca. 125 times) and two‐photon photoluminescence (ca. 14 times). The strengthened π–π interaction between the individual diamondoid networks and intensified oscillator strength of the molecules aid the augment of dipole moments and boost the nonlinear optical conversion efficiency. Large positive and negative thermal expansions of 1 occur at 30–150 °C before the loss of DMF. These results offer an avenue to manipulate the NLO properties of MOFs using interpenetration and provide access to tunable single‐crystal NLO devices. 相似文献