Enantioselective Synthesis of a Chiral Coordination Polymer with Circularly Polarized Visible Laser

Circular dichroism is known to be the feature of a chiral agent which has inspired scientist to study the interesting phenomena of circularly polarized light (CPL) modulated molecular chirality. Although several organic molecules or assemblies have been found to be CPL‐responsive, the influence of CPL on the assembly of chiral coordination compounds remains unknown. Herein, a chiral coordination polymer, which is constructed from achiral agents, was used to study the CPL‐induced enantioselective synthesis. By irradiation with either left‐handed or right‐handed CPL during the reaction and crystallization, enantiomeric excesses of the crystalline product were obtained. Left‐handed CPL resulted in crystals with a left‐handed helical structure, and right‐handed CPL led to crystals with a right‐handed helical structure. It is exciting that the absolute asymmetric synthesis of a chiral coordination polymer could be enantioselective when using CPL, and provides a strategy for the control of the chirality of chiral coordination polymers.     

电化学聚合漆酚稀土配合物的合成与表征

采用电化学方法合成的聚合漆酚(EPU)与三异丙氧基稀土Re(Pr,Nd,Eu)反应,生成稀土金属配合物(EPU-Re3+)。利用FT-IR、荧光光谱、XPS、DMTA、AES等手段对其表征,探讨其结构与性质。证明了配合物中存在着稀土金属离子Re3+与EPU的配位作用,并引起进一步的交联,因而难溶于绝大多数有机溶剂,而且其玻璃化转变温度和耐热性能均得到提高。     

聚合漆酚-镍配合物的电化学合成与性质研究

探讨了漆酚 (EPU)的电化学聚合及其聚合漆酚 镍配合物 (EPU_Ni2 +)的制备 .采用X光电子能谱、红外光谱、动态机械热分析 (DMTA)、TG_DTA、原子发射光谱 (AES)等手段对配合物(EPU_Ni2 +进行表征 .AES结果表明 :镍含量达 7.5 % .由于存在着Ni2 +与EPU的配位作用 ,并引起进一步交联 ,从而提高了玻璃化转变温度和耐热性能     

电化学聚合漆酚-镨配合物的合成及其表征

通过电化学方法合成的聚合漆物、与氯化镨作用生成聚合漆酚－镨配合物膜。采用原子发射光谱、红外光谱、荧光光谱、差热－热重分析、Ｘ光电子能谱和动态热分析等手段进行表征。探讨其结构与耐热性质。证明了螯合物中存在Ｐｒ＾３＋和ＥＰＵ的配位作用,并引起进一步交联,因而难溶于绝大多数有机溶剂,同时玻璃化转变温度和耐热性能均得提高。     

一种难溶多金属氧酸盐配位聚合物的重构与表征

利用电沉积法将不溶于常规无机和有机溶剂的多金属氧酸盐基的配位聚合物1, [{La(H₂O)₅·(dipic)}{La(H₂O)(dipic)}]₂{Mo₈O₂₆}·10H₂O溶解于离子液体[RMIM][HT]或[RMIM][HP]中, 在恒电位下电解, 得到多金属氧酸盐基的配位聚合物膜. 应用红外光谱、X射线光电子能谱和XRD粉末衍射等方法研究多金属氧酸盐基配位聚合物膜的结构, 发现其与多金属氧酸盐基配位聚合物有相同的结构. 实现了多金属氧酸盐基配位聚合物在电极上的重构设计以及多金属氧酸盐基的配位聚合物的二次加工成型.     

Facile synthesis of tough metallosupramolecular hydrogels by using phosphates as temporary ligands of ferric ions to avoid inhibition of polymerization

Forming carboxyl-Fe³⁺ coordination bonds as physical crosslinks is an effective strategy to develop tough hydrogels. Considering the inhibition of ferric ions on free-radical polymerization, these coordination bonds cannot be formed during the reaction, and a soaking process of preformed hydrogels is usually required for mechanical enhancement, resulting in uncontrollable gradient structure, long preparation time, and unnecessary waste of metallic ions. A facile strategy is reported here to prepare tough metallosupramolecular hydrogels by polymerization and in situ formation of coordination bonds with phosphates as the temporal ligands of Fe³⁺ ions. The phosphate ligands in the precursor solution form coordination complexes with the Fe³⁺ ions, which avoids the inhibition and ensures the polymerization. After swelling the resultant hydrogel in water, the ligands are substituted by carboxyl groups of the gel matrix due to the variation of local pH. The equilibrated hydrogel with carboxyl-Fe³⁺ coordination bonds as the physical crosslinks possesses excellent mechanical properties that can be tuned over a wide range by adjusting the polymer compositions and the concentrations of phosphate ligands and Fe³⁺ ions. This strategy should be applicable to other systems to enable synthesis of functional hydrogels with Fe³⁺ ions as the additive toward specific applications in engineering and biomedical fields.     

电聚合漆酚镝配位聚合物研究

根据漆酚结构特点和稀土元素的电子结构特殊性，研究电聚合漆酚（EPU）与 氯化镝反应生成配位聚合物（EPU－Dy~(3+)）,采用FT－IR，元素分析，XPS，荧光 光谱，DMTA，DTA－TG等手段对其进行表征，探讨其结构与性质，元素分析等测定 结构证明了每个Dy~(3+)分别与EPU分子中3个链节单元的羟基发生配位，从而得到 配位聚合物的结构，证实了配合物中存在着Dy~(3+)与EPU的配位作用，并引起进一 步交联，且镝含量达13.18%，DMTQ，DTA－TG分析结果表明玻璃化转变温度和耐热 性能均有所提高，荧光光谱表明EPU对Dy~(3+)不起敏化作用，EPU与Dy~(3+)配位后 使Dy的特征荧光淬灭。     

A conducting coordination polymer based on assembled Cu9 cages

We report on a novel highly semiconducting 1D coordination polymer architecture obtained by the reaction of a Cu(II) salt with 2,2'-dipyridyldisulfide under microwave solvothermal conditions. This reaction proceeds with an unusual C-S and S-S bond cleavage of the 2,2'-dipyridyldisulfide ligand. The unprecedented architecture of this coordination polymer consists of a 1D chain formed by the assembling of Cu9 cluster cages. The electrical conductivity behavior of this novel material suggests new perspectives for the use of coordination polymers as electrical conducting materials.     

电化学聚合漆酚钴膜配位结构与催化性能研究

电化学方法合成的聚合漆酚 (EPU)通过与氯化钴的异丙醇溶液作用 ,生成聚合漆酚钴配合物膜(EPU Co3+ ) .采用红外光谱、XPS光电子能谱、DTA TG、动态机械热分析 (DMTA)以及原子发射光谱 (AES)等手段进行表征 ,确定其配位结构 ,即每个钴离子与EPU中两个链节单元的羟基发生配位而交联 ,因此玻璃化转变温度和耐热性能均得到提高 .实验表明 ,此配合物膜在室温下的Na2 SO3水体系 (pH =7)中能催化引发VAc的聚合     

Linking homogeneous and heterogeneous enantioselective catalysis through a self-assembled coordination polymer

Combining the advantages of homogeneous and heterogeneous enantioselective catalysis is possible through self-supported copper coordination polymers, based on a new kind of ditopic chiral ligand bearing two azabis(oxazoline) moieties. When the coordination polymer is used to catalyze a cyclopropanation reaction, it becomes soluble in reaction conditions but precipitates after reaction completion, allowing easy recovery and efficient reuse in the same reaction up to 14 times.     

电化学聚合漆酚钴膜引发甲基丙烯酸甲酯（MMA）聚合的研究

利用电化学技术合成的聚合漆酚（EPU）与氯化钴的异丙醇溶液反应,得到电化学聚合漆酚钴配合物膜,经XPS光电子能谱、红外光谱、TG－DTA、动态机械热分析（DMTA）以及原子发射光谱（AES）等手段进行表征并确定其结构。由于每个钴离子与EPU分子中两个链节单元的羟基发生配位引进进一步交联。因此玻璃化转变温度和耐热性能均得到提高。实验表明,在常温下的Na2SO3水体系（pH值为7）中配合物膜能引发甲基丙烯酸甲酯（MMA）聚合。     

聚丙烯酸-铕-二苯甲酰甲烷配合物及其荧光性质的研究

将铕的有机配合物NaEu(DBM) 4与聚丙烯酸反应获得铕配位聚合物 (PAA Eu3+ DBM) .此配位聚合物是白色固体 ,不溶于大部分有机溶剂 ,只能溶于丙三醇和异丙醇的混合溶剂 .采用红外光谱、紫外光谱、X射线光电子能谱、电导率、元素分析和荧光光谱等手段对其结构和荧光性质进行表征 ,确定其配位组成和结构即每个铕离子分别与一个DBM分子和PAA分子中二个链节羧基发生配位 .荧光光谱表明PAA Eu3+ DBM有很好的荧光性     

A reusable enantioselective catalytic system for the Kharasch–Sosnovsky allylic oxidation of alkenes based on a ditopic azabis(oxazoline) ligand

An easily recoverable and reusable enantioselective catalytic system based on the self-assembly of a coordination polymer through the use of a chiral ditopic ligand, is described for the allylic oxidation of cycloalkenes with tert-butyl perbenzoate. Upon addition of the substrates and a coordinating solvent (acetone or acetonitrile) the coordination polymer disassembles, allowing the catalysis to take place in homogeneous phase. After completion of the reaction, the catalyst reassembles as a coordination polymer upon solvent evaporation and addition of hexane, and is recovered as an insoluble solid. This way, good enantioselectivities and yields are obtained in seven consecutive operation cycles.     

铽（III）-噻吩甲酰三氟丙酮-电化学聚合漆酚配合物的研究

研究了铽（III）和噻吩甲酰三氟丙酮（HTTA）形成的配合物与电化学聚合方 法得到的聚合漆酚（EPU）发生配位反应及pH = 10.2时形成配合物Tb(III)-TTA- EPU的组分和结构。红外光谱、X光电子能谱的测试表明Tb~(3+)分别与EPU,TTA~- 发生配位。元素分析和电感偶合等离子体发射光谱（AES）测定结果证明了每个 Tb~(3+)分别与EPU分子中1个链节单元的羟基和3个TTA~-发生配位,从而得到配合 物的结构。动态机械热分析（DMTA）表明发生配位反应后该配合物进一步交联,从 而难溶于大部分有机溶剂,其玻璃化转变温度和耐热性能均得到很大提高。我们对 其荧光性质进行了研究,发现常温下配合物在紫外光下发生强的荧光,主要是Tb~ (3+)离子的~5D_4→~7F_5的跃迁。讨论了溶剂、pH值对配合物荧光强度的影响。当 pH = 10.2时,合成的配合物有最好的荧光性质。     

First Tribo-Excited Chemical Reaction of a Stacked Lanthanide Coordination Polymer with an in Situ Reaction Monitor

A tribo-excited chemical reaction using a stacked lanthanide coordination polymer is demonstrated for the first time. The polymer is composed of a Eu^III ion, hexafluoroacetylacetonato ligands, and an anthracene-based phosphine oxide bridge. The tightly stacked structure with hydrogen bonding was characterized by X-ray crystal structure analysis. The mechanical stimulus leads to tribo-excited oxidation in the Eu^III coordination polymer. Electron ionization mass spectroscopy and photo-spectroscopic analysis reveal that the chemical product afforded by tribo-oxidation is different from that obtained by photo-oxidation.     

Non-centrosymmetric coordination polymer with a highly hindered octahedral copper center bridged by mandelate

A novel chiral coordination polymer, [Cu(C(6)H(5)CH(OH)COO)(μ-C(6)H(5)CH(OH)COO)] (1-L and 1-D), was synthesized through a reaction of copper acetate with L-mandelic acid at room temperature. Although previously reported copper mandelate prepared by hydrothermal reaction was a centrosymmetric coordination polymer because of the racemization of mandelic acid, the current coordination polymer shows noncentrosymmetry and a completely different structure from that previously reported. The X-ray crystallography for 1-L revealed that the copper center of the compound showed a highly distorted octahedral structure bridged by a chiral mandelate ligand in the unusual coordination mode to construct a one-dimensional (1D) zigzag chain structure. These 1D chains interdigitated each other to give a layered structure as a result of the formation of multiple aromatic interactions and hydrogen bonds between hydroxyl and carboxylate moieties at mandelate ligands. The coordination polymer 1-L belongs to the noncentrosymmetric space group of C2 to show piezoelectric properties and second harmonic generation (SHG) activity.     

Crystal structures of the coordination polymers formed between 1,2-bis(3′-pyridyl)ethyne and silver(I) trifluoromethanesulfonate

The reaction of 1,2-bis(3′-pyridyl)ethyne with silver(I) trifluoromethanesulfonate yields two coordination networks. A one-dimensional double-stranded coordination polymer was formed in acetonitrile. The silver has a square-planar coordination geometry with weak coordination to one acetonitrile molecule and the triflate counter ion. The second network, formed in dichloromethane, is a complex three-dimensional network of interconnected one-dimensional zig-zag ribbons.     

A three‐dimensional (3D) manganese (II) coordination polymer: Synthesis,structure and catalytic activities

A new Mn (II)‐containing coordination polymer, [Mn₆(Ipa)₆(ad)?6H₂O] ( 1 ; Ipa = isophthalate ligand; ad = adenine), was synthesized by reacting hydrated manganese nitrate with isophthalic acid and adenine under solvothermal reaction conditions. Polymer 1 was characterized using single‐crystal X‐ray diffraction analysis and other techniques such as Fourier transform infrared spectroscopy, elemental analyses and powder X‐ray diffraction. The solid‐state structure of 1 confirmed the formation of a three‐dimensional framework structure based on Mn₆ secondary building units. Phase purity of bulk 1 and its thermal stability were investigated. Polymer 1 was evaluated for its performance as a heterogeneous catalyst for the Henry (nitroaldol) reaction of nitromethane with several aldehydes. The recyclability of 1 and heterogeneity of the reaction were also explored. A plausible mechanism for such reaction is proposed. To the best of our knowledge, polymer 1 represents the first example of a Mn (II)‐ and adenine‐containing coordination polymer as well as the first example of a Mn (II)‐containing coordination polymer that has been employed for the Henry reaction.     

Metal–Organic Organopolymeric Hybrid Framework by Reversible [2+2] Cycloaddition Reaction

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 Zn^II 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.     

双咪唑基丁烷及邻苯二甲酸根构筑的镍多孔配位聚合物的合成、结构及性质研究

在水热反应条件下,合成了一种新的镍配位聚合物,[Ni(Pht)(bbim-4)]n(Pht=邻苯二甲酸阴离子,bbim-4=1,4-双(咪唑-1-基)丁烷),经元素分析、粉末X射线衍射、热重和X射线单晶衍射表征了配合物。该配合物属于单斜晶系,空间群C2/c。结构分析表明:该配合物是一个三维的具有三角形孔道的多孔配位聚合物。配位聚合物表现出一个整体上的铁磁行为。77 K温度下,气体吸附研究表明该多孔配位聚合物对N2和CO2气体的吸附具有选择性。