Selective product amplification of thymine photodimer by recognition-directed supramolecular assistance

Two symmetric ditopic supramolecular templates (1 and 2) each presenting two hydrogen bonding recognition subunits were synthesized. Each such subunit comprises the same donor and acceptor pattern, capable of binding a substrate molecule with complementary hydrogen bonding groups to form a supramolecular complex. Substrate molecules, such as thymine or uracil derivatives, yield 2 : 1 complexes with the acceptors involving two hydrogen bonds to each subunit with ideal orientation for subsequent [2 + 2] dimerization upon photoirradiation. Selective syn photoproduct formation and concomitant suppression of the trans isomer are favored by orientation of the two guest nucleobases within the template cleft. Complementary donor and acceptor hydrogen bonding induced positioning of the two substrates and steric hindrance within the template clefts are responsible for the selective product formation.     

Uranyl selenates with organic templates: Principles of structure and characteristics of self-organization

Basic structural principles of uranyl selenates with organic templates are outlined as follows. In compounds with short chain amine molecules (C:N < 8) the primary role plays the correspondence between topology of inorganic complex (isomerism) and structure and shape of a template. In the structures with long chain molecules (C:N ≤ 8), the molecules are associated to form 2- or 1-dimensional supramolecular templates that are connected with inorganic structure according to the charge density matching principle. Compounds with electro neutral molecules (crown ethers) have composite structure, where bonding between organic and inorganic parts is achieved through hydrogen bonding via intermediate oxonium clusters.     

Ligand design for alkali-metal-templated self-assembly of unique high-nuclearity CuII aggregates with diverse coordination cage units: crystal structures and properties

The construction of two unique, high-nuclearity Cu(II) supramolecular aggregates with tetrahedral or octahedral cage units, [(mu(3)-Cl)[Li subset Cu(4)(mu-L(1))(3)](3)](ClO(4))(8)(H(2)O)(4.5) (1) and [[Na(2) subset Cu(12)(mu-L(2))(8)(mu-Cl)(4)](ClO(4))(8)(H(2)O)(10)(H(3)O(+))(2)](infinity) (2) by alkali-metal-templated (Li(+) or Na(+)) self-assembly, was achieved by the use of two newly designed carboxylic-functionalized diazamesocyclic ligands, N,N'-bis(3-propionyloxy)-1,4-diazacycloheptane (H(2)L(1)) or 1,5-diazacyclooctane-N,N'-diacetate acid (H(2)L(2)). Complex 1 crystallizes in the trigonal R3c space group (a = b = 20.866(3), c = 126.26(4) A and Z = 12), and 2 in the triclinic P1 space group (a = 13.632(4), b = 14.754(4), c = 19.517(6) A, alpha = 99.836(6), beta = 95.793(5), gamma = 116.124(5) degrees and Z = 1). By subtle variation of the ligand structures and the alkali-metal templates, different polymeric motifs were obtained: a dodecanuclear architecture 1 consisting of three Cu(4) tetrahedral cage units with a Li(+) template, and a supramolecular chain 2 consisting of two crystallographically nonequivalent octahedral Cu(6) polyhedra with a Na(+) template. The effects of ligand functionality and alkali metal template ions on the self-assembly processes of both coordination supramolecular aggregates, and their magnetic behaviors are discussed in detail.     

Self-assembly and selective guest binding of three-dimensional open-framework solids from a macrocyclic complex as a trifunctional metal building block

The nickel(II) hexaazamacrocyclic complex (1) containing pendant pyridine groups has been synthesized by the one-pot template condensation reaction of amine and formaldehyde. From the self-assembly of 1 with deprotonated cis,cis-1,3,5-cyclohexanetricarboxylic acid, H2CTC- and CTC3-, three-dimensional supramolecular open-frameworks of [Ni(C20H32N8)][C6H9(COOH)2(COO)]2 x 4H2O (2) and [Ni(C20H32N8)]3[C6H9(COO)3]2 x 16H2O (3), respectively, have been constructed. The solids 2 and 3 are insoluble in all solvents. X-ray crystal structure of 2 indicates that each nickel(II) macrocyclic complex binds two H2CTC- ions in trans position and two pendant pyridine groups of the macrocyclic complex are involved in hydrogen-bonding interactions with the hydroxy groups of H2CTC- belonging to the neighboring macrocyclic complexes, which provides the beltlike one-dimensional chain composed of rectangular synthons. The one-dimensional chains are linked together through lattice water molecules by the hydrogen-bonding interactions to generate two-dimensional networks, which are again connected to each other by the offset pi-pi stacking interactions between the pendant pyridine rings to give rise to a three-dimensional structure in which channels are present. The X-ray crystal structure of 3 indicates that each nickel(II) macrocyclic unit binds two CTC3- ions in trans position and each CTC3- ion coordinates three nickel(II) macrocyclic complexes to form a two-dimensional layer, in which pendant pyridine rings are involved in the hydrogen bonding and the herringbone pi-pi interaction. Between the layers, the pendant pyridine rings belonging to the neighboring layers participate in the offset pi-pi stacking interactions, which gives rise to a three-dimensional network structure. The network creates channels running parallel to the a, b, and c axes, which are filled with guest water molecules. The X-ray powder diffraction patterns indicate that the frameworks of 2 and 3 are deformed upon removal of water guests but restored upon rebinding of water. The host solids 2 and 3 bind [Cu(NH3)4](ClO4)2 in MeCN with a binding constant (Kf) of 210 M(-1) and 710 M(-1), respectively, while they do not bind [Cu(en)2](ClO4)2 (en = ethylenediamine). The dried solids of 2 and 3 do not interact with benzene and toluene, but they differentiate methanol, ethanol, and phenol in toluene solvent with the Kf values of 42, 14, and 12 M(-1), respectively, for 2, and 13, 8.2, and 8.9 M(-1), respectively, for 3. In terms of binding sites for guest molecules, the solid 3 has greater capacity than the solid 2.     

Study of Self‐Assembly of the Lignin Model Compound on Cellulose Model Substrate

Herein we report a topographical study of the supramolecular organization of enzymatically polymerized lignin model compound – dehydrogenative polymer (DHP) of coniferyl alcohol – on cellulose substrate, using the Environmental Scanning Electron Microscopic (ESEM) technique. A comparison of deposits obtained by bulk polymerization in solution and direct polymerization in the presence of cellulose substrate shows distinct differences in supramolecular organization. DHP polymerized in solution expresses a 3‐D structure with short‐range ordered motifs, while the polymer formed in the presence of cellulose substrate arranges in a single layer compact structure consisting of several domains. Such structures could be described as a two‐dimensional hexagonal close packed lattice(HCPL), with the dimension of unit cell in 1 μm range. The domains have a quite regular structure with few lattice defects, forming a good example of two‐dimensional colloidal crystal. The growth of DHP globules and their assembly into supramolecular structures are interpreted in terms of cooperative electrostatic interaction of polymer precursors, with a framework of cellulose OH groups and interfacial interactions (hydrophilic/hydrophobic) in the course of the structure growth. The results strongly suggest that the carbohydrate matrix in plant cells can serve as a template for lignin structure formation in the plant cell wall.

Self‐assembled lignin model compound on cellulose substrate.     

Peptide Nanomaterials Designed from Natural Supramolecular Systems

Natural supramolecular assemblies exhibit unique structural and functional properties that have been optimized over the course of evolution. Inspired by these natural systems, various bio‐nanomaterials have been developed using peptides, proteins, and nucleic acids as components. Peptides are attractive building blocks because they enable the important domains of natural protein assemblies to be isolated and optimized while retaining the original structures and functions. Furthermore, the peptide subunits can be conjugated with exogenous molecules such as peptides, proteins, nucleic acids, and metal nanoparticles to generate advanced functions. In this personal account, we summarize recent progress in the construction of peptide‐based nanomaterial designed from natural supramolecular systems, including (1) artificial viral capsids, (2) self‐assembled nanofibers, and (3) protein‐binding motifs. The peptides inspired by nature should provide new design principles for bio‐nanomaterials.     

Formation of supramolecular cavitands on copper electrode surfaces

The adsorption of 1,1'-dibenzyl-4,4'-bipyridinium molecules (dibenzyl-viologen or DBV(2+) for the sake of simplicity) on chloride precovered Cu(100) has been studied in an electrochemical environment by means of cyclic voltammetry and in situ scanning tunneling microscopy. DBV(2+) spontaneously forms a highly ordered phase on the chloride c(2 x 2) adlayer at potentials close to the onset of the copper dissolution reaction when the pure supporting electrolyte (10 mM HCl/5 mM KCl) is exchanged by one also containing DBV(2+). This ordered phase can be described by a ( radical 53 x radical 53)R15.9 degrees unit cell relating the organic adlayer to the chloride c(2 x 2) structure underneath or alternatively by a ( radical 106 x radical 106)R29.05 degrees unit cell relating the organic layer to the Cu(1 x 1) substrate structure. Thus, the negatively charged chloride layer acts as a template for the adsorption and phase formation of DBV(2+). Compared to the copper-chloride interaction, the DBV(2+)-chloride interaction appears to be weaker since the organic layer can be easily removed from the surface by the tunneling tip when drastic tunneling conditions (low bias voltage, high tunneling current) are applied. A key structural element of the DBV(2+) adlayer is an assembly of four individual DBV(2+) molecules forming square-shaped supramolecular units with pronounced cavities in their center. Characteristically, the supramolecular assemblies reveal a preferential rotational orientation resulting in the appearance of two chiral forms of these assemblies. Furthermore, these two chiral supramolecular assemblies occur in two mirrored domains of the ( radical 53 x radical 53)R15.9 degrees structure. It can be assumed that these viologen-based supramolecular architectures can be used as potential host cavitands for the inclusion of smaller organic molecules.     

2D氢键网络镉配合物Cd(pyridine-2-sulfonato)2(H2O)2和锌配合物Zn(pyridine-2-sulfonato)2(H2O)2的合成和晶体结构

合成了镉的吡啶-2-磺酸配合物Cd(C5H4NSO3)2(H2O)2 1和锌的吡啶-2-磺酸配合物Zn(C5H4NSO3)2(H2O)2 2。 研究表明, 2个化合物属异质同晶, 均属单斜晶系, 空间群为C2/c. 化合物1晶胞参数为:a = 13.7671(5), b = 7.2778(3), c = 16.1559(9) ? b = 106.656(3)? V = 1550.8(1) 3, Z = 4, Dc = 1.990 g/cm3, m =1.719 mm-1, F(000) = 920, R = 0.0225, wR = 0.0584, 共收集到1759个独立衍射点, 其中I≥2(I)的可观测点为1681个;化合物2晶胞参数为:a = 13.711(1), b = 7.1451(9), c = 15.972(1) , b =107.079(5)? V = 1495.7(3) 3, Z = 4, Dc = 1.855 g/cm3, m = 1.964 mm-1, F(000) = 848, R = 0.0310, wR = 0.0831, 共收集到1707个独立衍射点, 其中I≥2(I)的可观测点为1592个。在2个标题配合物中, Cd2+离子(或Zn2+离子)由2个吡啶-2-磺酸中的2个氮和2个氧以及2个水分子中的2个氧配位形成畸变的N2O4八面体配位构型。每个配合物分子具有晶体学2次旋转轴对称性。配合物分子之间通过许多OH(配位水分子)LO(未配位磺酸根)氢键联结成二维结构网络。     

Stereochemical effects in supramolecular self-assembly at surfaces: 1-D versus 2-D enantiomorphic ordering for PVBA and PEBA on Ag(111)

We present investigations on noncovalent bonding and supramolecular self-assembly of two related molecular building blocks at a noble metal surface: 4-[trans-2-(pyrid-4-yl-vinyl)]benzoic acid (PVBA) and 4-[(pyrid-4-yl-ethynyl)]benzoic acid (PEBA). These rigid, rodlike molecules comprising the same complementary moieties for hydrogen bond formation are comparable in shape and size. For PVBA, the ethenylene moiety accounts for two-dimensional (2-D) chirality upon confinement to a surface; PEBA is linear and thus 2-D achiral. Molecular films were deposited on a Ag(111) surface by organic molecular beam epitaxy and characterized by scanning tunneling microscopy. At low temperatures (around 150 K), both species form irregular networks of flat lying molecules linked via their endgroups in a diffusion-limited aggregation process. In the absence of kinetic limitations (adsorption or annealing at room temperature), hydrogen-bonded supramolecular assemblies form which are markedly different. With PVBA, enantiomorphic twin chains in two mirror-symmetric species running along a high-symmetry direction of the substrate lattice form by diastereoselective self-assembly of one enantiomer. The chirality signature is strictly correlated between neighboring twin chains. Enantiopure one-dimensional (1-D) supramolecular nanogratings with tunable periodicity evolve at intermediate coverages, reflecting chiral resolution in micrometer domains. In contrast, PEBA assembles in 2-D hydrogen-bonded islands, which are enantiomorphic because of the orientation of the supramolecular arrangements along low-symmetry directions of the substrate. Thus, for PVBA, chiral molecules form 1-D enantiomorphic supramolecular structures because of mesoscopic resolution of a 2-D chiral species, whereas with PEBA, the packing of an achiral species causes 2-D enantiomorphic arrangements. Model simulations of supramolecular ordering provide a deeper understanding of the stability of these systems.     

Writing with molecules on molecular printboards

Nanotechnology aspires to create functional materials with characteristic dimensions of the order 1-100 nm. One requirement to make nanotechnology work is to precisely position molecules and nanoparticles on surfaces, so that they may be addressed and manipulated for bottom-up construction of nanoscale devices. Here we review the concept of a "molecular printboard". A molecular printboard is a monolayer of host molecules on a solid substrate on which guest molecules can be attached with control over position, binding strength, and binding dynamics. To this end, cyclodextrins were immobilized in monomolecular layers on gold, on silicon wafers and on glass. Guest molecules (for example, adamantane and ferrocene derivatives) bind to these host surfaces through supramolecular, hydrophobic inclusion interaction. Multivalent interactions are exploited to tune the binding strength and dynamics of the interaction of guest molecules with the printboard. Molecules can be positioned onto the printboard using supramolecular microcontact printing and supramolecular dip-pen nanolithography due to the specific interaction between the 'ink' and the substrate. In this way, nanoscale patterns can be written and erased on the printboard. Currently, the molecular printboard is exploited for nanofabrication, for example in combination with electroless deposition of metals and by means of supramolecular layer-by-layer deposition.     

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.     

一维链状配位聚合物[Pb_2(C_8H_7O_2)_4(H_2O)_2]_n的合成、晶体结构及荧光性质

<正>近年来,铅的配位聚合物以其丰富的结构与在离子交换和光学等领域中的应用前景[1-3]而引起了广泛关注。由于铅的原子半径较大,可以形成较高的配位数[4-6];另外,二价铅的6s轨道上有一对孤对     

Template-assisted ligand encapsulation; the impact of an unusual coordination geometry on a supramolecular pyridylphosphine-Zn(II)porphyrin assembly

The tris(para-pyridyl)phosphine template (1) has been used in conjunction with a series of meso-substituted Zn(II)-tetraphenylporphyrins complexes (2-10) to create supramolecular encapsulated ligand assemblies via Zn-N(pyr) interactions. The structural features of supramolecular ligand 1.[2](3) have been investigated in detail using X-ray crystallography, NMR specroscopy, and UV-vis spectroscopy. The pyridylphosphine-porphyrin stoichiometry determined in solution (1:3) differs markedly with that observed in the solid state (2:5, for assembly [1](2).[2](5)). The difference originates from an unusual coordination behavior of one of the Zn centers, which is octahedrally surrounded through double axial coordination by the pyridyl groups of the two different molecules of 1.     

Synthesis, Crystal Structure and Photoluminescent Property of a Novel Silver(I) Compound {[Ag(bpp)]_2(Hphth)(NO_3)·(H_2O)_2}_n

Self-assembly of Ag(I) nitrate, 1,3-bis(4-pyridyl)propane (bpp) and phthalic acid monopotassium salt (KHphth) in CH3OH-H2O solution produced the title complex, {[Ag(bpp)]2(Hphth)(NO3)·(H2O)2}n, which was characterized by single-crystal X-ray diffraction, elemental analysis, IR spectrum, and photoluminescent spectrum. Single-crystal X-ray analysis revealed that the complex crystallizes in a monoclinic system, space group P21/c, with a = 15.4174(5), b = 8.6398(2), c = 25.2466(8) , β = 91.072(1)o, V = 3362.34(17) 3, Z = 4, C34H37N5O9Ag2, Mr = 875.43, Dc = 1.729 g/cm3, μ = 1.228 mm-1, F(000) = 1768, the final R = 0.0749 and wR = 0.1580 for 5754 reflections with I > 2σ(I). The Ag atom is coordinated by two N atoms from two bpp molecules in an approximately linear geometry. The Ag(I) ions are linked by the bpp molecules to form one-dimensional zigzag chains propagating along the c axis. The Hphth- and nitrate counter-ions are bridged by solvent water molecules through hydrogen bonds to generate a one-dimensional chain extending along the b axis. Electrostatic interactions between cations and anions, extensive hydrogen bonds and π-π interactions are responsible for the three-dimensional supramolecular structure. In the solid state, the compound exhibits blue photoluminescence with the maximum at 436 nm upon excitation at 344 nm.     

Supramolecular pattern of fullerene on 2D bimolecular "chessboard" consisting of bottom-up assembly of porphyrin and phthalocyanine molecules

Two-component adlayers consisting of zinc(II) phthalocyanine (ZnPc) and a metalloporphyrin, such as zinc(II) octaethylporphyrin (ZnOEP) or zinc(II) tetraphenylporphyrin (ZnTPP), were prepared by immersing either an Au(111) or Au(100) substrate in a benzene solution containing those molecules. The bimolecular adlayers thus prepared were investigated in 0.1 M HClO4 by cyclic voltammetry (CV) and electrochemical scanning tunneling microscopy (EC-STM). A supramolecularly organized "chessboard" structure was formed for the ZnPc and ZnOEP bimolecular array on Au(111), while characteristic nanohexagons were found in the ZnTPP and ZnOEP bimolecular adlayer. EC-STM revealed that the surface mobility and the molecular re-organization of ZnPc and ZnOEP on Au(111) were tunable by manipulating the electrode potential, whereas the ZnTPP and ZnOEP bimolecular array was independent of the electrode potential. A "bottom-up" hybrid assembly of fullerene molecules was formed successfully on an alternate array of bimolecular ZnPc and ZnOEP molecules. The bimolecular "chessboard" served as a template to form the supramolecular assembly of C60 by selective trapping in the open spaces. A supramolecular organization of ZnPc and ZnOEP was also found on the reconstructed Au(100)-(hex) surface. A highly ordered, compositionally disordered but alternate array of ZnPc and ZnOEP was formed on the reconstructed Au(100)-(hex) surface, indicating that the bimolecular adlayer structure is dependent on the atomic arrangement of underlying Au in the formation of supramolecular nanostructures composed of those molecules. On the bimolecular array consisting of ZnPc and ZnOEP on the Au(100)-(hex), no highly ordered supramolecular assembly of C60 was found, suggesting that the supramolecular assembly of C60 molecules is strongly dependent upon the bimolecular packing arrangement of ZnPc and ZnOEP.     

毒死蜱分子印迹聚合物微球的制备及结合特性的研究

采用无皂乳液聚合法制得的微米级聚苯乙烯微球为种球,以毒死蜱为模板分子,通过单步溶胀聚合法制备了单分散分子印迹聚合物微球（MIPMs）。通过紫外光谱研究了MIPMs的结合机理和识别特性;利用红外光谱分析MIPMs的结合位点;运用扫描电子显微镜对微球进行形貌分析,MIPMs的粒径分布为0.5～3 μm（UMIPMs为2～3 μm）,其表面粗糙具有一定层次孔径分布的多孔性聚合物,有利于底物和结合位点的接触,从而获得高负载量和高效识别性;Scatchard 分析表明MIPMs在识别毒死蜱过程中存在两类结合位点,计算得高亲和性位点的解离常数为 KD1 = 0.526 mmol/L,最大表观结合量Bmax1 = 35.91 μmol/ g,低亲和位点的解离常数为 KD2 = 2.19 mmol/L,最大表观结合量Bmax1 = 83.87 μmol/g。     

One-step template-directed synthesis of a macrocyclic tetraarylporphyrin hexamer based on supramolecular interactions with a C3-symmetric tetraarylporphyrin trimer

Taking into consideration the model geometry of the macrocyclic hexaporphyrin 1 as a host molecule, the structure of a benzene-centered porphyrin trimer bearing pyridine rings at the apical positions has been designed with the aim to use the latter as a template for the synthesis of its own host. Indeed, in the presence of the porphyrin trimer 5, the yield of the cyclization of a linear porphyrin hexamer, as a precursor of 1, could be improved from 8 to 30% (variable yield) to 50% (reproducible yield). Even the condensation of equimolecular amounts of porphyrin monomers 20b and 21b in the presence of 5 led--probably through a loose preorganized complex between the latter and the Zn(II) chelate 20b--to the formation of 1 in only five steps from 19, as compared with 13 steps of the synthesis via linear porphyrin hexamer in the absence of template. As evidenced by 1H NMR spectroscopic analysis of the supramolecular complex between 5 and an analogue of 1b in which all H-atoms at the pyrrole rings have been replaced by deuterium, in the presence of unlabeled 1b, a rapid dissociation and recombination of the host and guest molecules forming the supramolecular complex takes place even at low temperature (-40 degrees C). As at 55 degrees C all six Zn(II) porphyrinate rings of the complex 1b + 5 become magnetically equivalent in the 500 MHz 1H NMR time scale, approximate kinetic data for the ligand exchange process could be obtained.     

Crystal Structure and Properties of a Copper(Ⅱ) Complex Containing p-Toluenesulfonate and Imidazole Ligands

A novel supramolecular mixed ligand complex of formula [Cu(PTS)2(Him)2(H2O)2] (C20H26CuN4O8S2,PTS=p-toluenesulfonate,Him=imidazole) has been synthesized in aqueous solution and characterized by elemental analysis,IR and single-crystal X-ray diffraction.The compound crystallizes in the monoclinic system,space group P21/n,Z=2,a=5.650(2),b=14.671(3),c=14.638(3),β=100.10(3)°,V=1194.60(4)3,Dc=1.607 g/cm3,μ(MoKα)=1.143 mm-1,F(000)=598,R=0.0615 and wR=0.1503 for 1752 observed reflections with I 2σ(I).The copper(II) ion in the complex adopts a slightly distorted octahedral coordination geometry and is six-coordinated with N2O4 donor set consisting of two nitrogen atoms and four oxygen atoms provided by the ligands of two imidazole molecules,two water molecules and two p-toluenesulfonate ions.The sulfonate group of the PTS ligand remains weak-coordinated and forms a number of hydrogen bonds with water molecules and imidazole ligands.X-ray structural analysis reveals that the coordination molecules are connected to form a 3-D supramolecular framework by electrostatic interaction,weak van der Waals forces,hydrogen bonding and π-π interaction.The thermal behaviour of the title complex was investigated by using DSC and TG-DTG techniques.     

Synthesis, Crystal Structure and Photoluminescent Property of a Novel Silver(Ⅰ) Compound {[Ag(bpp)]2(Hphth)(NO3)·(H2O)2}n

Self-assembly of Ag(Ⅰ) nitrate, 1,3-bis(4-pyridyl)propane (bpp) and phthalic acid monopotassium salt (KHphth) in CH3OH-H2O solution produced the title complex,{[Ag(bpp)]2(Hphth)(NO3)·(H2O)2}n, which was characterized by single-crystal X-ray diffraction,elemental analysis, IR spectrum, and photoluminescent spectrum. Single-crystal X-ray analysis revealed that the complex crystallizes in a monoclinic system, space group P21/c, with α =15.4174(5), b = 8.6398(2), c = 25.2466(8) (A), β = 91.072(1)°, V = 3362.34(17) (A)3, Z = 4,C34H37N5O9Ag2, Mr = 875.43, Dc = 1.729 g/cm3, μ = 1.228 mm-1, F(000) = 1768, the final R =0.0749 and wR = 0.1580 for 5754 reflections with I ＞ 2σ(I). The Ag atom is coordinated by two N atoms from two bpp molecules in an approximately linear geometry. The Ag(Ⅰ) ions are linked by the bpp molecules to form one-dimensional zigzag chains propagating along the c axis. The Hphth-and nitrate counter-ions are bridged by solvent water molecules through hydrogen bonds to generate a one-dimensional chain extending along the b axis. Electrostatic interactions between cations and anions, extensive hydrogen bonds and π-π interactions are responsible for the three-dimensional supramolecular structure. In the solid state, the compound exhibits blue photoluminescence with the maximum at 436 nm upon excitation at 344 nm.     

Urothermal Synthesis and Crystal Structure of a Zn（Ⅱ） Coordination Polymer with a 3-D Supramolecular Structure

A new metal-organic coordination polymer [Zn(hfipbb)(e-urea)]n(1,H2hfipbb = 4,4'-(hexafluoroisopropylidene)bis(benzoic acid),e-urea = ethylene urea) has been urothermally synthesized and characterized by elemental analysis and single-crystal X-ray diffraction.The title complex crystallizes in monoclinic,space group P21/c with a = 13.302(4),b = 10.981(3),c = 13.804(4) ,β = 93.587(5)°,V = 2012.3(10) 3,C20H14N2O5F6Zn,Mr = 541.72,Z = 4,Dc = 0.447 g/cm3, = 0.328 mm-1,F(000) = 272,R = 0.0340 and wR = 0.1107 for 4528 observed reflections(I >2σ(I)).In the structure of compound 1,two Zn(Ⅱ) ions are bridged by two carboxylate groups from two hfipbb ligands to form a dinuclear unit,and each dinuclear Zn(Ⅱ) unit is linked with its two adjacent dinuclear units through four hfipbb ligands into an infinite one-dimensional double-chain.The interesting structural feature of compound 1 is that the one-D double-chains are self-interconnected into a three-D supramolecular structure through hydrogen bonds between the coordinated e-urea molecules and carboxylate oxygen atoms(N1 and O2,N2 and O4).