Optically active 1‐methylpropargyl esters bearing various substituents were polymerized with [(nbd)Rh]+[η6‐C6H5B(C6H5)3]? (nbd=norbornadiene) as a catalyst to afford the corresponding poly(1‐methylpropargyl ester)s with moderate molecular weights in good yields. The polymers have a cis‐stereoregular structure, which was determined by 1H NMR spectroscopy. Large optical rotations and clear CD signals demonstrated that all these polymers take on a helical structure with a predominantly one‐handed screw sense. The polymers exhibited large viscosity indices in the range 1.14–1.75. Chiral amplification was observed in R/S copolymerization. Conformational analysis revealed that the polymers form a tightly twisted helical structure with a dihedral angle of 70° at the single bond of the main chain. 相似文献
Novel chiral methylpropargyl esters bearing azobenzene groups, namely, 4‐[4′‐(benzyloxy)phenylazophenyl]‐ carbonyl‐(S)‐1‐methylpropargyl ester ( e ), 4‐[4′‐(n‐butyloxy)phenylazophenyl]carbonyl‐(S)‐1‐methylpropargyl ester ( f ), 4‐[4′‐(n‐hexyloxy)phenylazophenyl]carbonyl‐(S)‐1‐methylpropargyl ester ( g ), and 4‐[4′‐(n‐octyloxy)phenylazo‐ phenyl]carbonyl‐(S)‐1‐methylpropargyl ester ( h ) were synthesized and polymerized with Rh+(nbd)[η6‐C6H5B?‐ (C6H5)3] (nbd=norbornadiene) catalyst to give the corresponding polymers with moderate molecular weights (Mn=8.4×103–15.7×103) in good yields (76%? –?91%). The structures of polymers were illustrated by IR and NMR spectroscopies. Polymers were soluble in comment organic solvents including toluene, CHCl3 CH2Cl2, THF, and DMSO, while insoluble in diethyl ether, n‐hexane and methanol. Large optical rotations of polymer solutions demonstrated that all the polymers take a helical structure with a predominantly one‐handed screw sense in organic solvents. 相似文献
5‐[(Imidazol‐1‐yl)methyl]benzene‐1,3‐dicarboxylic acid (H2L) was synthesized and the dimethylformamide‐ and dimethylacetamide‐solvated structures of its adducts with CuII, namely catena‐poly[[copper(II)‐bis[μ‐3‐carboxy‐5‐[(imidazol‐1‐yl)methyl]benzoato]] dimethylformamide disolvate], {[Cu(C12H9N2O4)2]·2C3H7NO}n, (I), and catena‐poly[[copper(II)‐bis[μ‐3‐carboxy‐5‐[(imidazol‐1‐yl)methyl]benzoato]] dimethylacetamide disolvate], {[Cu(C12H9N2O4)2]·2C4H9NO}n, (II), the formation of which are associated with mono‐deprotonation of H2L. The two structures are isomorphous and isometric. They consist of one‐dimensional coordination polymers of the organic ligand with CuII in a 2:1 ratio, [Cu(μ‐HL)2]n, crystallizing as the dimethylformamide (DMF) or dimethylacetamide (DMA) disolvates. The CuII cations are characterized by a coordination number of six, being located on centres of crystallographic inversion. In the polymeric chains, each CuII cation is linked to four neighbouring HL− ligands, and the organic ligand is coordinated via Cu—O and Cu—N bonds to two CuII cations. In the corresponding crystal structures of (I) and (II), the coordination chains, aligned parallel to the c axis, are further interlinked by strong hydrogen bonds between the noncoordinated carboxy groups in one array and the coordinated carboxylate groups of neighbouring chains. Molecules of DMF and DMA (disordered) are accommodated at the interface between adjacent polymeric assemblies. This report provides the first structural evidence for the formation of coordination polymers with H2Lvia multiple metal–ligand bonds through both carboxylate and imidazole groups. 相似文献
Careful choice of the organic ligands is one of the most important parameters in the rational design and synthesis of coordination polymers. Aromatic polycarboxylates have been widely used in the preparation of metal–organic polymers since they can utilize various coordination modes to form diverse structures and can act as hydrogen‐bond acceptors and donors in the assembly of supramolecular structures. Nitrogen‐heterocyclic organic compounds have also been used extensively as ligands for the construction of polymers with interesting structures. In the polymers catena‐poly[[[diaquabis{2‐[(1H‐imidazol‐1‐yl)methyl]‐6‐methyl‐1H‐benzimidazole‐κN 3}cobalt(II)]‐μ2‐benzene‐1,4‐dicarboxylato‐κ2O 1:O 4] dihydrate], {[Co(C8H4O4)(C12H11N4)2(H2O)2]·2H2O}n , (I), and catena‐poly[[[diaquabis{2‐[(1H‐imidazol‐1‐yl)methyl]‐6‐methyl‐1H‐benzimidazole‐κN 3}nickel(II)]‐μ2‐benzene‐1,4‐dicarboxylato‐κ2O 1:O 4] dihydrate], {[Ni(C8H4O4)(C12H11N4)2(H2O)2]·2H2O}n , (II), the CoII or NiII ion lies on an inversion centre and exhibits a slightly distorted octahedral coordination geometry, coordinated by two N atoms from two imidazole rings and four O atoms from two monodentate carboxylate groups and two water molecules. The dicarboxylate ligands bridge metal ions forming a polymeric chain. The 2‐[(1H‐imidazol‐1‐yl)methyl]‐6‐methyl‐1H‐benzimidazole ligands coordinate to the CoII or NiII centres in monodentate modes through an imidazole N atom and are pendant on opposite sides of the main chain. The two structures are isomorphous. In the crystal, the one‐dimensional chains are further connected through O—H…O, O—H…N and N—H…O hydrogen bonds, leading to a three‐dimensional supramolecular architecture. In addition, the IR spectroscopic properties, PXRD patterns, thermogravimetric behaviours and fluorescence properties of both polymers have been investigated. 相似文献
((?)‐Menthyl (S)‐6′‐acrylyl‐2′‐methyloxy‐1,1′‐binaphthalene‐2‐carboxylate ( 3 ) was synthesized and anionically polymerized using n‐BuLi as an initiator in toluene. The monomer 3 was levorotatory and had an [α]D25 value of ?72.4, but its corresponding polymer poly‐ 3 was dextrorotatory and showed an [α]D25 value of +162.0. Poly‐ 3 was confirmed to exist in the form of one‐handed helical structure in solution by means of comparing the specific optical rotation and the CD spectra with that of 3 and the model compounds such as (?)‐menthyl (S)‐6′‐propionyl‐2′‐methyloxy‐1,1′‐binaphthalene‐2‐carboxylate 2b and (?)‐menthyl (S)‐6′‐heptanoyl‐2′‐methyloxy‐1,1′‐binaphthalene‐2‐carboxylate 2c . This conclusion was also confirmed by the fact that the g‐value of poly‐ 3 is about 11 times of that of monomer 3 . 相似文献
Crystals of poly[[aqua[μ3‐4‐carboxy‐1‐(4‐carboxylatobenzyl)‐2‐propyl‐1H‐imidazole‐5‐carboxylato‐κ5O1O1′:N3,O4:O5][μ4‐1‐(4‐carboxylatobenzyl)‐2‐propyl‐1H‐imidazole‐4‐carboxylato‐κ7N3,O4:O4,O4′:O1,O1′:O1]cadmium(II)] monohydrate], {[Cd2(C15H14N2O4)(C16H14N2O6)(H2O)]·H2O}n or {[Cd2(Hcpimda)(cpima)(H2O)]·H2O}n, (I), were obtained from 1‐(4‐carboxybenzyl)‐2‐propyl‐1H‐imidazole‐4,5‐dicarboxylic acid (H3cpimda) and cadmium(II) chloride under hydrothermal conditions. The structure indicates that in‐situ decarboxylation of H3cpimda occurred during the synthesis process. The asymmetric unit consists of two Cd2+ centres, one 4‐carboxy‐1‐(4‐carboxylatobenzyl)‐2‐propyl‐1H‐imidazole‐5‐carboxylate (Hcpimda2−) anion, one 1‐(4‐carboxylatobenzyl)‐2‐propyl‐1H‐imidazole‐4‐carboxylate (cpima2−) anion, one coordinated water molecule and one lattice water molecule. One Cd2+ centre, i.e. Cd1, is hexacoordinated and displays a slightly distorted octahedral CdN2O4 geometry. The other Cd centre, i.e. Cd2, is coordinated by seven O atoms originating from one Hcpimda2− ligand and three cpima2− ligands. This Cd2+ centre can be described as having a distorted capped octahedral coordination geometry. Two carboxylate groups of the benzoate moieties of two cpima2− ligands bridge between Cd2 centres to generate [Cd2O2] units, which are further linked by two cpima2− ligands to produce one‐dimensional (1D) infinite chains based around large 26‐membered rings. Meanwhile, adjacent Cd1 centres are linked by Hcpimda2− ligands to generate 1D zigzag chains. The two types of chains are linked through a μ2‐η2 bidentate bridging mode from an O atom of an imidazole carboxylate unit of cpima2− to give a two‐dimensional (2D) coordination polymer. The simplified 2D net structure can be described as a 3,6‐coordinated net which has a (43)2(46.66.83) topology. Furthermore, the FT–IR spectroscopic properties, photoluminescence properties, powder X‐ray diffraction (PXRD) pattern and thermogravimetric behaviour of the polymer have been investigated. 相似文献
Three 1H‐benzimidazole‐5‐carboxylate (Hbic–)‐based coordination polymers, {[Ni(H2O)(Hbic)2] · 2H2O}n ( 1 ), {[Ni(H2O)2(Hbic)2] · 3H2O}n ( 2 ), and {[Co2(H2O)4(Hbic)4] · 4DMF · 3H2O}n ( 3 ) were obtained by reactions of the ligand H2bic and NiII or CoII salts in the presence of different structure directing molecules. They were structurally characterized by single‐crystal X‐ray diffraction, IR spectra, elemental analysis, thermal stability, luminescent, and magnetic measurements. Structural analysis suggests that the three polymers exhibit a 2D (4, 4) layer for 1 and 1D linear double chains for both 2 and 3 due to the variable binding modes and the specific spatial orientation of the Hbic– ligand towards the different paramagnetic metal ions, which were further aggregated into different 3D supramolecular architectures by popular hydrogen‐bonding interactions. Weak and comparable antiferromagnetic couplings mediating by Hbic– bridge are observed between the neighboring spin carriers for 2 and 3 , respectively. Additionally, complexes 1 – 3 also display different luminescence emissions at room temperature due to the ligand‐to‐metal charge transfer. 相似文献
The title compound, [Th(C12H15O4)4]n, is the first homoleptic thorium–carboxylate coordination polymer. It has a one‐dimensional structure supported by the bidentate bridging coordination of the singly charged 3‐carboxyadamantane‐1‐carboxylate (HADC−) anions. The metal ion is situated on a fourfold axis (site symmetry 4) and possesses a square‐antiprismatic ThO8 coordination, including four bonds to anionic carboxylate groups [Th—O = 2.359 (2) Å] and four to neutral carboxyl groups [Th—O = 2.426 (2) Å], while a strong hydrogen bond between these two kinds of O‐atom donor [O...O = 2.494 (3) Å] affords planar pseudo‐chelated Th{CO2...HO2C} cycles. This combination of coordination and hydrogen bonding is responsible for the generation of quadruple helical strands of HADC− ligands, which are wrapped around a linear chain of ThIV ions [Th...Th = 7.5240 (4) Å] defining the helical axis. 相似文献
Summary: 2,2,6,6‐Tetramethylpiperidine 1‐oxyl (TEMPO)‐containing N‐propargylamide HCCCH2NHCO‐4‐TEMPO ( 1 ), propargyl ester HCCCH2OCO‐4‐TEMPO ( 2 ), phenylacetylene derivative HCCC6H3‐3,4‐(CO2‐4‐TEMPO)2 ( 3 ), and norbornene diester monomers, NB‐2,3‐exo,exo‐(CH2OCO‐4‐TEMPO)2 ( 4 ), NB‐2,3‐endo,exo‐(COO‐4‐TEMPO)2 ( 5a ), NB‐2,3‐endo,endo‐(COO‐4‐TEMPO)2 ( 5b ) (NB = norbornene, TEMPO = 2,2,6,6‐tetramethyl‐1‐piperidinyloxyl) were synthesized and polymerized with rhodium and ruthenium catalysts. Monomers 2 , 5a , and 5b gave polymers with number‐average molecular weights of 47 000–185 000 in 59–100% yields, while 1 , 3 , and 4 gave polymers insoluble in common organic solvents in 88–100% yields. The capacities of cells fabricated with poly( 1 ), poly( 2 ), and poly( 3 ) were 67, 82, and 23 Ah · kg−1 based on the weight, respectively. The capacity of poly( 5a )‐based cell reached the theoretical value (109 Ah · kg−1) of the polymer.
Charge–discharge curves of poly( 5a ) at a current density of 0.13 mA · cm−2 (100 mA · g−1‐cathode active material) in the voltage range of 2.5–4.2 V. 相似文献