A 3-D Supramolecular Framework with Open Channels Constructed from Lanthanide Ions and Mixed Ligands

A 3-D supramolecular framework, [Er（pybz）2（Hnds）（H2O）2]·H2O （1, Hpybz = 4- pyridin-4-yl-benzoic acid, H2nds = naphthalene-1,5-disulfonic acid）, based on lanthanide ions and mixed ligands has been hydrothermally synthesized. The structure was determined by single-crystal X-ray diffraction and further characterized by IR, elemental analysis and thermogravimetric analysis. Compound 1 crystallizes in the monoclinic system, space group P21/n with a = 9.849（2）, b = 22.526（5）, c = 17.167（4） A, β =105.461（4）° and V = 3670.9（2） A^3. In 1, two seven-coordinated Er^3＋ ions are bridged by two pybz^- ligands to form a dimeric [Er2（COO）2] unit, which is further orderly linked by carboxyl of pybz^-ligand to obtain a 1-D chain running along the a axis. Interestingly, significant H-bonding and π-π stacking interactions link the neighboring parallel chains leading to a 3-D supramolecular network structure which displays 1-D rhombus open channels （17.2A× 22.5A）.

1-D Open-channeled 3-D Supramolecular Frameworks Built with 2,3-Dihydroxybutanedioic Acid (H_4dhbd) and 2,2':6',2'-Terpyridine (tpy)~i

The complex [Cu2（H2dhbd）2（tpy）2]·CH3OH·4H2O 1 （H4dhbd =2,3-dihydroxybutanedioic acid, tpy = 2,2＇：6＇,2＇＇-terpyridine） has been hydrothermally synthesized and characterized by single-crystal X-ray diffraction analysis. The crystal is of triclinic, space groups Pi with a= 8.6859（17）, b = 11.223（2）, c = 12.275（2）A, α = 112.454（3）, β= 98.435（3）, γ = 105.593（3）°, V= 1022.5（3） A^3, Z = 1, C38H42Cu2N6O18, Mr = 997.86, Dc = 1.621 g/cm^3, μ= 1.127 mm^-1, F（000） = 514, T = 293（2） K, the final R = 0.0539 and wR = 0.1394 for 3550 observed reflections with I 〉 2σ（I）. In the dinuclear unit, two Cun atoms are bridged by two H2dhbd chelate anions, forming a 14-membered ring, in which the distance of Cu…Cu atoms is 7.0526（12）A. Adjacent dinuclear units are constituted through π-π interactions and C-H…O hydrogen-bonding interactions, fashioning the final 3-D supramolecular framework with 1-D open channels. Variable-temperature magnetic susceptibility measurement indicates the presence of weak antiferromagnetic exchange interactions between Cu^II ions.

A New 3-D Supramolecular Framework Built by Co4-Substituted Sandwiched Phosphotungstates, Organoamines and Co-Complexes: Synthesis, Structure, and Property

A neoteric organic-inorganic hybrid Co-substituted phosphotungstate H6{[Co(en)2(OAc)2]2[Co4(H2 O)2(PW9 O34)2]}?2 H2 en?36 H2 O(1, en = enthylenediamine) has been made under hydrothermal conditions and characterized by IR spectrum, thermogravimetric analysis, diffuse-reflectance spectroscopy, powder X-ray diffraction, single-crystal X-ray diffraction and cyclic voltammetry, respectively. Crystal data for 1: monoclinic, P21/c, a = 18.2234(12), b = 15.3696(9), c = 20.1706(17) ?, β = 106.563(8)°, V = 5415.1(7) ?3, Z = 2, Mr = 6072.30, Dc = 3.724 g/cm3, μ = 20.087 mm-1, F(000) = 5540, R = 0.0585, w R = 0.1543 and S = 1.024. Single-crystal X-ray structure analysis reveals that compound 1 exhibits a 3-D supramolecular framework via H-bonding interactions, in which the discrete Co-complex is modified by two types of organic ligands, en and acetate. In addition, the adsorption experiments demonstrate compound 1 possesses a remarkable capability for scavenging of methylene blue.

Solid-state molecular dynamics of a torsion-variable ammonium embedded in a deformable supramolecular framework

Accompanied by solid-state structural phase transitions,the switchable molecular dynamics(MD)and order-disorder transformation of(i-PrNHMe2)^(+)cation embedded in a deformable{[Ni(NCS)_(6)]^(4-)}_(∞)supramolecular framework are in-depth investigated by variable-temperature tests of single-crystal X-ray diffraction,dielectric measurement,and MD simulation.Interestingly,it is found that the confined swinging or flipping of the(i-PrNHMe_(2))^(+)cation as a whole is assisted by a synergistic change of its torsion angle.This research provides a helpful insight into the solid-state MD of moderate-sized quasi-spherical molecules/ions that feature a flexible inner core.

Stabilizing the Extrinsic Porosity in Metal-Organic Cages-Based Supramolecular Framework by In Situ Catalytic Polymerization

Porous supramolecular frameworks based on metal-organic cages(MOCs)usually have poor structural stability after activation.This issue narrows the scope of their potential applications,particularly for the inclusion of guest molecules that demand high porosity.Herein,the authors have reported the stabilization of a mesoporous zirconium MOC-based supramolecular framework with an in situ catalytic polymerization strategy.Due to the passivation effect imparted by this strategy,the introduced polymer is primarily distributed on the surface of the crystals,which results in the hybrid material retaining its crystallinity and permanent porosity.A preliminary application of this type of stabilized mesoporous supramolecular framework shows that among MOC-based supramolecular frameworks,it has the highest high-pressure methane uptake.Such a facile strategy may provide a general way to stabilize fragile porous materials and facilitate exploration of their potential applications.

An ultra-stable microporous supramolecular framework with highly selective adsorption and separation of water over ethanol

A microporous supramolecular framework with high water and thermal stability can selectively absorb water molecules over methanol or ethanol due to the suitable channels.The model separation test on columns shows that an ultra-pure ethanol(99.9%)can be obtained from the mixture of ethanol/water(95:5).Additionally,after refluxing the desolvated sample in 95%ethanol at 60℃for 5 h,the purity of ethanol rises up to 97.43%,which is obviously higher than 96.56%for 4 A molecular sieves.

Two New Alkaline Metal Borates with Supramolecular Framework Constructed from 1D{B5}/{B6}Helical Chains

Two new alkaline metal borates containing 1D{B5}/{B6}oxoboron helical chains,namely Na0.5[B5O8(OH)2]0.5[B5O6(OH)2]0.5·0.5H3O(1)and NaKCs[B6O9(OH)3](2)were synthesized under solvothermal conditions.Compound 1 contains the interesting alternative left-and right-handed helical{[B5O8(OH)2][B5O6(OH)2]}2-({B5}-1 and{B5}-2)1D chains and compound 2 possesses the similar[B6O11(OH)3]7-({B6})chains.Their 1D chains are further assembled into 2D layers and 3D supramolecular frameworks through O-H…O hydrogen bonds.In addition,the UV cutoff edge of compounds 1 and 2 is both below 190 nm.

Cucurbit[n]uril-calix[n]arene-based supramolecular frameworks assembled using the outer surface interactions of cucurbit[n]urils

Based on the crystal structures of two cucurbit[6]uril/calix[n]arene-based supramolecular frameworks reported by Long and co-workers,we further investigated the interactions of cucurbit[6]uril with 4-sulfocalix[4]arene and 4-sulfocalix[6]arene using ^(1)H NMR spectroscopy and isothermal titration calorimetry(ITC),respectively.Moreover,solid fluorescent materials were prepared via the adsorption of fluorescent dyes by these porous supramolecular frameworks,which exhibit a selective response to certain volatile organic compounds.

Cucurbit[6]uril-based supramolecular frameworks assembled via the outer surface interaction of cucurbit[n]urils

Curcurbit[n]uril(Q[n])-based supramolecular frameworks(QSFs) constructed from the outer surface interaction of Q[n]s(OSIQ) have the characteristic of simplicity,diversity and modulability.Their simplicity is reflected in their simple composition and preparation methods used for QSFs.The diversity of supramolecular organic frameworks(SOFs) is reflected in the synthesis methods and structural characteristics of the as-obtained QSFs,as well as the variety of structural directing agents and basic building blocks used to prepare QSFs.The modulability is reflected by the controllable channel size in the QSFs,which can be adjusted using different sizes of Q[n]s.In this work,the first re ported cucurbituril Q[6]was selected as the basic building block and three Q[6]-based su p ramolecular frameworks were obtained from aqueous HCl solutions in the presence of [CdCl_(4)]^(2-)respectively.The OSIQs are the main driving forces for the formation of these frameworks.This study shows the diversity of the QSFs.

Structural modulation of Cd(Ⅱ) supramolecular frameworks with a versatile 2,4-dipyridyl-type building block and different dicarboxylate ligands

A series of Cd(Ⅱ) coordination complexes with an elongated 2,4-dipyridyl-type building block trans-1-(2-pyridyl)-2-(4-pyridyl)ethylene (bpe) and different dicarboxylate ligands have been presented. Generally, bpe shows the unidentate coordination mode and serves as the terminal pendant, whereas the dicarboxylate ligands display various binding fashions to interlink the metal centers to form 1-D comb-like chain, ribbon, and fishbone arrays, as well as 2-D 44 and 4.82 layered networks. Notably, the bpe building block is also involved in secondary interactions such as hydrogen bonding and aromatic stacking to construct the resulting supramolecular architectures. Thermal stability of these complexes has been studied by TG-DTA technique.

High adsorption and separation performance of CO_(2) over N2 in azo-based(N=N)pillar[6]arene supramolecular organic frameworks

Azo-based pillar[6]arene supramolecular organic frameworks are reported for CO_(2) and N_(2) adsorption and separation by density functional theory and grand canonical Monte–Carlo simulation.Azo-based pillar[6]arene provides suitable environment for CO_(2) adsorption and selectivity.The adsorption and selectivity results show that introducing azo groups can effectively improve CO_(2) adsorption and selectivity over N_(2),and both CO_(2) adsorption and CO_(2) selectivity over N_(2) follow the sequence pillar[6]arene N_(4)>pillar[6]arene N2>pillar[6]arene.Pillar[6]arene N_(4) exhibits CO_(2) adsorption capacity of1.36 mmol/g,and superior selectivity of CO_(2) over N_(2) of116.75 with equal molar fraction at 1 bar(1 bar=105 Pa)and 298 K.Interaction analysis confirms that both the Coulomb and van derWaals interactions between CO_(2) with pillar[6]arene frameworks are greater than that of N_(2).The stronger affinity of CO_(2) with pillar[6]arene N_(4) than other structures and the larger isosteric heat differences between CO_(2) and N2 rendered pillar[6]arene N4 to present the high CO_(2) adsorption capacity and high CO_(2) selectivity over N_(2).Our results highlight the potential of azo-functionalization as an excellent means to improve pillar[6]arene for CO_(2) capture and separation.

氧化石墨烯辅助的超分子骨架膜用于水包油型纳米乳液的高效分离

制备可以同时高效且高通量地处理纳米乳液的超浸润材料仍然具有挑战。为此,本文提出了一种通过在超分子骨架纳米片上修饰氧化石墨烯以增强亲水性的策略。通过将两种具有片状形态的材料连续抽滤于商业基质上,可制备得到氧化石墨烯辅助的超分子骨架复合膜,并用于分离具有纳米尺寸液滴的水包油乳液。骨架一方面通过均匀的纳米孔拦截乳液中分散的微小液滴,另一方面也通过带负电的表面提供静电相互作用来驱动破乳过程发生。具有良好亲水性的氧化石墨烯赋予膜材料改善的亲水能力和水合层。该复合膜具有纳米级的截留尺寸、带负电的表面和水下疏油性,并且还获得了高的水通量和耐油污染性。基于尺寸筛分和破乳效应,该复合膜可有效地去除分散在水包油乳液中由非离子、阴离子和阳离子表面活性剂稳定的纳米油滴。特别是对于离子型乳液,在分离后动态光散射未检测出残留液滴。滤液中总有机碳含量小于10 ppm,对应着大于99.9%的分离效率,优于许多国家和组织的标准。在各种乳液的分离过程中,复合膜表现出较高的分离渗透性,约为原始骨架膜的3.5倍。此外,具有防污效果的复合膜获得了较高的通量回收率,通过简单的水洗处理即可实现5次具有稳定分离性能的循环。该复合膜在重复使用过程中没有组分损失,在150℃内具有热稳定性,并能抵抗腐蚀性化学环境。在本工作中,我们试图将具有不同结构特性和表面特性的两种组分结合,通过简单的方法制备复合膜,并在功能协同作用下实现水包油型纳米乳液的高性能分离。

Synthesis and Crystal Structure of a New Cadmium(Ⅱ) Supramolecular Network Containing Chelating Imidazole-4-carboxylate Ligand

A new complex, [Cd（Himc）2（H2O）2] 1, obtained from imidazole-4-carboxylatic acid （H2imc） and Cd（ClO4）2·6H2O, has been synthesized. The crystal structure was determined by X-ray diffraction. The title compound crystallizes in the orthorhombic system, space group Pccn, with a = 7.4886（11）, b = 11.9667（18）, c = 13.550（2） A, V= 1214.3（3） A3, Z = 4, Mr= 370.60, Dc = 2.027 mg/m3, F（000） = 728,μ （MoKa） = 1.829 mm^-1, the final R = 0.0243 and wR = 0.0591 for 1150 unique reflections with I 〉 2σ（I）. The cadmium（II） center in the title complex is coordinated with two oxygen and two nitrogen atoms from two bidentate chelated imidazole-4-carboxlate ligands together with two water molecules, giving a distorted octahedral coordination geometry. A one-dimensional hydrogen bonding chain is formed via intermolecular O-H...O hydrogen bonds, and such adjacent chains are further stacked through intermolecular π-π and hydrogen bonding interactions to form a 3D supramolecular framework. Complex 1 exhibits a fluorescent emission band at 290 nm （λex = 236 nm） in the solid state.

Synthesis,Crystal Structure and Magnetic Properties of a Ni(Ⅱ) Supramolecular Complex Based on Aromatic Polycarboxylate Ligand

A Ni（Ⅱ） supramolecular complex,[Ni 2 （btec）（3py） 2 （H 2 O） 8 ]（H 2 O） 4 （1）,has been synthesized by Ni（ClO 4） 2 ·6H 2 O,benzene-1,2,4,5-tetracarboxylic acid （H 4 btec） and terminal ligand 3-hydroxypyridine （3py） in aqueous solution.The title compound crystallizes in triclinic system,space group P1,with a=8.5637（12）,b=9.4138（13）,c=10.3611（14）,α=67.9540（10）,β=85.1740（10）,γ=76.9890（10）°,V=754.33（18） 3,Z=2,M r=386.96,D c=1.704 Mg/m 3,μ=1.345 mm-1,F（000）=402,the final R=0.0222 and wR=0.0563 for 2675 observed reflections with I 2σ（Ⅰ）.The adjacent discrete molecules are further self-assembled by intermolecular π-π and O-H···O hydrogen bonding interactions to construct a 3D supramolecular framework.Magnetic measurement shows weak ferromagnetic interaction in the range of 2～300 K.

3D Supramolecular Network Based on Hydrogen Bonds Between 1D [Ni(μ_2-C_2O_4)(Him)_2] Zigzag Chains

In recent years, considerable attention has been paid to supramolecular networks based on metal organic building blocks because of their potential applications in diverse fields, such as, catalysis, optics, sensors, magnetism, and molecular recognition^[1-3]. On the ba- sis of the principles of crystal engineering and special synthesis strategies, several novel supramolecular frameworks have been assembled from various organic, inorganic and metal-organic moieties, which largely en- riches the structure chemistry of solid state materi-als^[4-9].

Dimension-Controllable and Photo-Responsive Supramolecular Organic Framworks through Cucurbit[8]uril-based Self-Assembly

Dimension-controllable supramolecular organic frameworks(SOFs)with aggregation-enhanced fluorescence are hierarchically fabricated through the host-guest interactions of cucurbit[8]uril(CB[8])and coumarin-modified tetraphenylethylene derivatives(TPEC).The three-dimensional layered SOFs could be constructed from the further stacking of two-dimensional mono-layered structures via simply regulating the self-assembly conditions including the culturing time and concentration.Upon light irradiation under the wavelength of 365 nm,the photodimerization of coumarin moieties occurred,which resulted in the transformation of the resultant TPECn/CB[8]4n two-dimensional SOFs into robust covalently-connected 2D polymers with molecular thickness.Interestingly,the supramolecular system of TPEC/CB[8]exhibited intriguing multicolor fluorescence emission from yellow to blue in the time range of 0-24 h at 365 nm irradiation,possessing potential applicability for photochromic fluorescence ink.

与外壁作用相关的瓜环基超分子化学

自从2014年提出瓜环外壁作用的概念以来,促进了“瓜环外壁作用”相关的瓜环化学发展。瓜环外壁作用源于静电势呈正性的外壁与各种静电势呈负性的物种、阴离子以及含芳环有机分子等的相互作用,因而涉及多学科多领域。如外壁作用可驱动瓜环基超分子框架的构筑,根据作用方式的不同,包括:1)自身诱导外壁作用;2)阴离子诱导外壁作用;3)芳环诱导外壁作用等多种构筑方式,而所构筑的瓜环基超分子框架可能涉及到(杂)多酸化学、杯芳烃或柱芳烃化学等,同样也具有框架多孔材料特有的多相催化、吸附和离子交换等特性。设计和构建具有结构新颖和性质特异的瓜环基超分子框架,不仅能进一步扩展框架化学的研究内容,还能开辟新的研究方向。作为最重要的驱动力——自身诱导外壁作用能促使瓜环产生光致聚集发光,这是所有瓜环固有属性。瓜环在固体状态和溶液状态下呈现光致发光特性,而另外2种外壁作用——阴离子诱导和芳环诱导外壁作用则能削弱或改变瓜环聚集状态光致发光特性。这些外壁作用导致的瓜环聚集状态光致发光特性的差异恰好可用于不同阴离子或有机分子的响应,具有重要的基础研究价值和广泛的潜在应用前景。再者,瓜环的自身诱导外壁作用致使瓜环分子具有相互聚集的特性,加之瓜环端口羰基氧的亲水固有属性,因此瓜环还具有形成水凝胶的倾向,可能被应用于生物学、医学、保健等诸多领域。若结合瓜环的光致聚集发光特性,瓜环可形成光致发光的水凝胶。

[5]Rotaxane, linear polymer and supramolecular organic framework constructed by nor-seco-cucurbit[10]uril-based ternary complexation

Here we use nor-seco-cucurbit[10]uril(ns-CB[10]) based ternary complexation to construct [5]rotaxane,linear supramolecular dynamic rotaxane polymers and cubic 3D supramolecular organic framework.A [5]rotaxane is constructed by ns-CB[10], TMe CB[6] and short linear derivatives of 4,4'-bipyridinium(M2). ns-CB[10], CB[7] and long linear derivatives of 4,4'-bipyridinium(M3) self-assemble into a linear supramolecular dynamic rotaxane polymer. ns-CB[10] and tetracationic tetrahedral monomer selfassemble and form a three-dimensional supramolecular organic framework. The above results demonstrate that ns-CB[10]-based ternary complexation is a versatile platform to build various supramolecular systems.

Chiral supramolecular 2D halogen-bonded organic frameworks constructed by post-synthetic modified cross-linking strategy

The development of preparation methods for XOFs,as a new class of organic frameworks,plays a crucial role in shaping their structures,functions,and potential applications.In this study,we presented the construction of chiral supramolecular 2D halogen-bonded organic frameworks(XOFs)through a post-synthetic modification strategy.A linear halogen-bonded organic polymer(XOP),XOP-DPBA,decorated with aldehyde groups,was initially prepared to validate the feasibility of post-synthetic modification for XOF construction and functionalization.XOP-DPBA exhibited excellent reactivity with amines,forming imine bonds.By utilizing this reactivity,a series of cross-linked 2D XOFs were efficiently prepared through post-synthetic modified cross-linking reactions.Furthermore,we successfully introduced chiralα/β-cyclodextrins(α/β-CD)into the XOF skeletons via host-guest interactions,resulting in the fabrication of chiral supramolecular 2D XOFs.These chiral XOFs displayed the induced circular dichroism(ICD)signals and assembled them into helical fibers.The post-synthetic modification strategy demonstrated its versatility and simplicity for the construction and functionalization of XOFs.

基于双吡啶基双西佛碱通过氢键相互作用形成的有机超分子晶体

合成了双吡啶双西佛碱(bpbd)有机分子,并用该分子进行了超分子网络晶体的组装.X射线单晶结构分析表明:在bpbd晶体中存在着分子间氢键相互作用,该氢键由吡啶环上的N原子和西佛碱H—CN基团上的H原子相互作用而成.每一个bpbd分子同另外4个bpbd分子通过氢键相连,构成了二维网状结构;在bpbd晶体中还存在分子间π…π相互作用,并导致一维分子柱的形成.二维氢键和一维π…π的协同作用,导致了三维超分子晶体的形成.