Variability in the structures of [4-(aminomethyl)pyridine]silver(I) complexes through effects of ligand ratio, anion, hydrogen bonding, and pi-stacking

The reaction of the asymmetric 4-(aminomethyl)pyridine (4-amp) ligand with silver(I) salts of trifluoromethanesulfonate (triflate, OTf(-)), trifluoroacetate (tfa(-)), or tetrafluoroborate (BF(4)(-)) have produced a variety of one- and two-dimensional structural motifs depending upon the ratio in which the components are mixed. When the proportion of ligand to metal is 1:1, linear coordination polymers are formed with silver(I) OTf(-) (1) and tfa(-) (2). Altering the ratio to 2:1, a linear polymer of corner-shared boxes (3) is formed with tfa(-), a linear box-in-box "chain link" polymer (4) is formed with OTf(-), and a two-dimensional sheet (5) is constructed with BF(4)(-). Addition of 5,5'-dimethyl-2,2'-bipyridine to a solution of 4-ampAgBF(4) disrupts the polymerization of the previous structure and results in the construction of the infinite metal-metal bound strings of 6a regardless of ratio of amp to silver present. H-bonding, pi-stacking, and closed-shell Ag-Ag interactions are all involved in the overall conformations of the final structures.     

Temperature-dependent 3-D CuI coordination polymers of calix[4]-bis-dithiacrown: crystal-to-crystal transformation and photoluminescence change on coordinated solvent removal

The temperature-dependent assembly of two 3-D CuI coordination polymers containing calix[4]-bis-thiacrown with different networking motifs are reported. Upon removal of the coordinated solvent molecules the initial solvent-coordinated polymer undergoes a unique single-crystal-to-single-crystal transformation to the desolvated polymer. Structural characteristics observed in the solvent-coordinated and the desolvated polymers also reveal related solvato-photolunimescence "off-on" behavior.     

1D and 2D homochiral metal-organic frameworks built from a new chiral elongated binaphthalene-derived bipyridine

Six homochiral coordination polymers 1-6 based on a new enantiopure elongated (S)-2,2'-diethoxy-1,1'-binaphthyl-6,6'-bis(4-vinylpyridine) ligand (L) and divalent metal (Zn, Cd, and Ni) connecting points were synthesized and characterized by single-crystal X-ray diffraction studies. These new homochiral coordination polymers adopt two distinct framework structures: a one-dimensional infinite chain structure with bridging L ligands occupying the axial positions of the metal centers and a two-dimensional rhombic grid structure formed by linking octahedrally coordinated metal centers with four pyridyl groups of bridging L ligands in the equatorial positions. The structures of these coordination polymers are sensitive to the nature of the anions as well as the solvents from which the coordination polymer crystals were grown. Powder X-ray diffraction studies showed that the two-dimensional chiral rhombic grids exhibited porosity, which could potentially find applications in enantioselective separations and catalysis.     

Spontaneously resolved homochiral 3D lanthanide-silver heterometallic coordination framework with extended helical Ln-O-Ag subunits

Two novel homochiral lanthanide-silver heterometallic coordination polymers LnAg(OAc)(IN)3 [Ln = Nd (1), Eu (2), HIN = isonicotinic acid, HOAc = acetic acid] have been prepared under hydrothermal conditions, which were characterized by elemental analysis, infrared, thermogravimetric analysis, and single-crystal X-ray diffraction. Both complexes are isostructural and crystallize in a hexagonal system, chiral space group P6(1)22. Both polymers are constructed from infinite right-handed homochiral helical chains with Ln-O-Ag connectivity, representing the first examples of homochiral lanthanide-transition metal heterometallic coordination polymers with a 3D coordination framework based on spontaneous resolution. Furthermore, the luminescent properties of 2 were studied.     

Stimuli‐Responsive Metallogels for Synthesizing Ag Nanoparticles and Sensing Hazardous Gases

A newly synthesized bis‐pyridyl ligand having a diphenyl ether backbone ( LP6 ) displayed the ability to form crystalline coordination polymers ( CP1‐CP6 ) which were fully characterized by single crystal X‐ray diffraction. Most of the resulting polymers were lattice‐occluded crystalline solids—a structural characteristic reminiscent to gels. The reactants of the coordination polymers produced metallogels in DMSO/water confirming the validity of the design principles with which the coordination polymers were synthesized. Some of the metallogels displayed material properties like in situ synthesis of Ag nanoparticles and stimuli‐responsive gel–sol transition including sensing hazardous gases like ammonia and hydrogen sulfide.     

Polytypism, homochirality, interpenetration, and hydrogen-bonding in transition metal (Mn(II), Ni(II), Cu(II), Zn(II)) 5-hydroxyisophthalate coordination polymers containing 4,4'-bipyridyl

We report the synthesis of five coordination polymers of divalent transition metals combined with 5-hydroxyisophthalic acid (HIP) and 4,4'-bipyridyl (bipy). Mn forms two polytypic two-dimensional coordination polymers, Mn(HIP)(bipy).3H(2)O and Mn(HIP)(bipy).(1/4)bipy.2H(2)O (I and II, with ABAB and ABC stacking sequences, respectively); Ni forms a chiral hexagonal three-dimensional coordination polymer with two interpenetrating trigonal sublattices exhibiting the "dual quartz" topology, Ni(HIP)(bipy)(H(2)O) (III); Cu forms a one-dimensional coordination polymer containing arrays of infinite hydrogen-bonded molecular ribbons, Cu(HIP)(2)(bipy) (IV); and Zn forms a two-dimensional coordination polymer with a stair-stepped layered structure, Zn(2)(HIP)(2)(bipy)(H(2)O)(2).H(2)O (V). The M-HIP-M connections are perpendicular to the M-bipy-M connections in all structures where they are present.     

Hydrothermal Synthesis,Crystal Structure and Thermal Properties of a Novel Samarium Complex with 1D Nano-chain Structure

1 Introduction The design and construction of metal-organic polymers has been a field of rapid growth in materials chemistry because of their intriguing topologies and potential applications as functional materials[1―6]. In     

系列Co-aip聚物的合成、结构及表面光电性能

采用水热法合成了3种以5-氨基间苯二甲酸根为桥连配体的Co(Ⅱ)配聚物:[Co2(aip)2(bipy)]n·2nH2O(1),[Co(aip)(imH)]n(2)和[Co(aip)(phen)]n(3)(H2aip=5-氨基间苯二甲酸,bipy=2,2′-联吡啶,imH=咪唑,phen=1,10-邻菲啰啉).通过X射...     

Dynamic photoswitching of helical inversion in liquid crystals containing photoresponsive axially chiral dopants

Chirality switching is intriguing for the dynamic control of the electronic and optical properties in nanoscale materials. The ability to photochemically switch the chirality in liquid crystals (LCs) is especially attractive given their potential applications in electro-optic displays, optical data storage, and the asymmetric synthesis of organic molecules and polymers. Here, we present a dynamic photoswitching of the helical inversion in chiral nematic LCs (N*-LCs) that contain photoresponsive axially chiral dopants. Novel photoresponsive chiral dithienylethene derivatives bearing two axially chiral binaphthyl moieties are synthesized. The dihedral angle of the binaphthyl rings changes via the photoisomerization between the open and closed forms of the dithienylethene moiety. The N*-LCs induced by the dithienylethene derivatives that are used as chiral dopants exhibit reversible photoswitching behaviors, including a helical inversion in the N*-LC and a phase transition between the N*-LC and the nematic LC. The present compounds are the first chiral dopants that induce a helical inversion in N*-LC via the photoisomerization between open and closed forms of the dithienylethene moiety.     

Three-dimensional mesomeric networks assembled from helix-linked sheets: syntheses, structures, and magnetisms

Two new three-dimensional nickel coordination polymers, [Ni3(BTC)2(4,4'-bpy)2(H2O)5].1.5H2O (1) and [Ni(PDB)(4,4'-bpy)].0.5H2O (2)(4,4'-bpy = bipyridine, BTC = 1,2,4-benzenetricarboxylate, PDB = pyridine-3,4-dicarboxylate), have been synthesized under hydrothermal conditions and characterized by elemental analysis, IR, TGA, and single crystal X-ray diffraction. Both compounds contain 2D scaffolding motifs, and most interestingly adjacent scaffolds are connected by infinite helical chains into unique three-dimensional mesomeric networks. Moreover, temperature-dependent magnetic susceptibilities for the two compounds were studied, and ferromagnetic interactions through syn-anti carboxylate bridges between Ni sites have been observed.     

Synthesis and structural properties of porphyrin analogues of bacteriochlorophyll c

The self-assembling photosynthetic pigment bacteriochlorophyll c contains α-hydroxyethyl and keto groups on opposite sides of the macrocycle. A porphyrin has been synthesized that contains a 3-hydroxymethyl group and a 15-ethoxycarbonyl group (ZnP2-OH). X-ray analysis of ZnP2-OH and the related porphyrin containing 5-hydroxymethyl and 15-ethoxycarbonyl groups (ZnP1-OH) in each case revealed infinite coordination polymers wherein the zinc porphyrins are bound by Zn-O coordination and are cofacially offset in a staircase architecture.     

A novel, tunable manganese coordination system based on a flexible "spacer" unit: noncovalent templation effects.

The reaction of bis(hexafluoroacetylacetonato)manganese(II) trihydrate (2), an approximately 90 degrees corner unit, with flexible linking unit 4,4'-trimethylenedipyridine (1) allows for the potential formation of three different types of solid-state coordination species: infinite helical polymers, closed dimeric systems, and infinite one-dimensional polymers. While the un-templated starting material is known to give a coordination helix, the other two possible species can be realized through the selective use of a variety of simple, organic guests: toluene (3), diphenylmethane (4), cis-stilbene (5), 1,3-diphenylpropane (6), benzyl alcohol (7), nitrobenzene (8), and cyanobenzene (9). When solutions of 1 and 2 are crystallized in the presence of all of these clathrates, the dimeric macrocycles result in all cases, except for that of 6, in which a syndiotactic, wedge-shaped polymer forms. Employing a linker that is less rigid than is typically used in crystal engineering, such as 1, enables the nucleophilic donor subunit to be more than just a simple "spacer", instead making it an essential, tunable component in the overall crystal lattice. In so doing, a great deal of molecular "information" is lost, but this is compensated for by an in-depth investigation into the weaker host-guest and/or guest-guest interactions, such as nonclassical hydrogen bonding and an assortment of hydrophobic interactions, present in the various systems.     

Helical (isotactic) and syndiotactic silver(I) metallo-supramolecular coordination polymers assembled from a readily prepared bis-pyridylimine ligand containing a 1,5-naphthalene spacer

A ligand in which two pyridylimine binding units are linked by a 1,5-naphthalene spacer is prepared and its silver(I) coordination chemistry investigated. In the solid state, a pair of C-H triplebond N interactions between pyridylimine units link the free ligands into chain structures, with further C-H triplebond N and some -stacking interactions linking these chains into a three-dimensional structure. The spacer constrains the ligand to dinucleate, and with silver(I) the metal coordinates to two pyridylimine units from two separate ligands and this leads to the formation of coordination polymers with a range of different anions. Different twisting motifs within the ligand control the tacticity of these coordination polymers and both isotactic, helical polymers and syndiotactic (achiral) polymers result. The core of the isotactic polymer strands contains two metallo-vectors and results in long-range ordering of the metal centres into a 2 x n grid arrangement. The solution behaviour indicates that exchange between the diastereomeric forms occurs. Since this must involve inversion at the metal centres, atactic species may also form a component of the solution library.     

Flexible microporous coordination polymers

In a decade, many porous coordination polymers have been synthesized, providing a variety of properties ranging from storage, separation and exchange of guests in their cavities, magnetism, conductivity and catalysis by their frameworks. Recent advent of flexible porous coordination polymers, which exhibit elastic guest accommodation in contrast to rigid three-dimensional (3-D) frameworks of conventional porous materials, have acquired a position as a new class of porous materials. Such flexible porous properties induce highly selective guest accommodation and magnetic modulation, which could now be a unique class of practical materials. In this review, we introduce recent flexible porous coordination polymers (3-17) and their functional properties, categorizing with the four types of pores with framework deformation.     

Guest shape-responsive fitting of porous coordination polymer with shrinkable framework

In situ synchrotron X-ray powder diffraction patterns of porous coordination polymers [[Cu(2)(pzdc)(2)(bpy)].G] have been measured (pzdc = pyrazine-2,3-dicarboxylate, bpy = 4,4'-bipyridine) (where G = H(2)O for CPL-2 superset H(2)()O, G = benzene for CPL-2 superset benzene, and G = void for the apohost). The structures of apohost and CPL-2 superset benzene were determined from Rietveld analysis. Adsorption of benzene in the channels induced a remarkable contraction in the crystal (b axis; 6.8%, volume; 4.9%), although the channels were occupied by the benzene molecules. This crystal transformation provides a new pore structure that is well suited for benzene molecules, and we denote it as a "shape-responsive fitting" transformation. This type of pore gives rise to a new guideline: frameworks can be composed of flexible motifs that are linked via strong bond and/or stiff motifs that are connected via weaker bonds.     

Metalloporphyrins in macromolecular chemistry

The review presents an analysis of the data on the synthesis of metalloporphyrin-based polymers of different structure. Manufacturing coordination polymers via extra coordination of small molecules and fragments of high-molecular-weight compounds by porphyrin metal complexes are discussed. The main approaches to the development of functional materials based on these polymers are summarized.     

Mn(Ⅱ)配位聚合物的合成、结构及光物理性能

采用水热方法合成了2种结构新颖的Mn(Ⅱ)配位聚合物,[Mn(m-tpha)(phen)]_n(1),{[Mn₃(m-tpha)₂(m-Htpha)₂(bipy)₂]·3H₂O}_n (2),(m-H₂tpha=间苯二甲酸,phen=1,10-邻菲咯啉,bipy=2,2′-联吡啶)。通过X-射线单晶衍射、红外光谱(IR)、紫外光谱(UV-Vis)、表面光电压光谱(SPS)和场诱导表面光电压光谱(FISPS)等方法对配聚物进行了表征。结构分析表明:配聚物(1)和(2)均是通过间苯二甲酸根桥连的具有1D无限结构的Mn(Ⅱ)配聚物。不同的是(1)的不对称单元中只包含1个Mn(Ⅱ)离子,它采取了N₂O₄的配位模式;而(2)的重复单元中,包含3个Mn(Ⅱ)离子,其中有2个Mn(Ⅱ)离子是晶体学等效的,它们也采取了N₂O₄的配位模式,另1个Mn(Ⅱ)离子处于一个几乎规则的正八面体场的配位环境中,6个配位原子均为O。配聚物的表面光电压光谱测试表明,它们在300～800 nm范围内都呈现正的表面光伏响应(SPV),但是光伏响应带的强度、数量是明显不同的。这是它们的结构、中心金属Mn(Ⅱ)离子的配位微环境不同所致。将配聚物的SPS与其UV-Vis光谱进行对比,可以看出SPS响应带与UV-Vis吸收峰基本是对应的。     

Synthesis and photoisomerization of dithienylethene-bridged diporphyrins

Dithienylethene-bridged diporphyrins 1-6 were prepared as photochemical switching molecules. Porphyrin and dithienylethene are directly linked in 1, and linked, respectively, through a 1,4-phenylene spacer in 2, through a 4-ethynylphenylene spacer in 3, and through a di-4-phenylethynylene spacer in 4, while meso-ethynylated porphyrin and dithienylethene are directly connected in 5 and linked through a 1,4-phenylene spacer in 6. Compounds 1, 2, and 5 do not undergo any photochemical isomerization, probably due to efficient quenching of the excited dithienylethene by the attached porphyrin moiety via intramolecular energy transfer. Compounds 4 and 6 undergo open-to-closed and closed-to-open photoisomerizations in quantum yields of 4.3 x 10(-)(2) and 1.8 x 10(-)(3), and 2.6 x 10(-)(3) and 7.5 x 10(-)(4), respectively, by irradiation with 313 and 625 nm light, which are considerably smaller than quantum yields of 0.52 and 3.8 x 10(-)(3) for reference dithienylethene molecule 7. The fluorescence of 4 was regulated in a reversible manner by the photoisomerization of the dithienylethene moiety. In addition, the absorption properties of the porphyrin in 6 changed in response to the photochromic reaction of the dithienylethene bridge.     

Unprecedented NaI-CuII-LnIII heterometallic coordination polymers based on 3,5-pyrazoledicarboxylate with both infinite cationic and anionic chains

The self-assembly of 3,5-pyrazoledicarboxylic acid (H3pdc) and metal salts under hydrothermal conditions leads to the formation of a series of novel NaI-CuII-LnIII heterometallic coordination polymers, [[Na(H2O)4]2[Cu(pdc)2Ln(H2O)5]2 x 3H2O]n [Ln = La (1); Sm (2); Pr (3); Nd (4) and pdc3- = 3,5-pyrazoledicarboxylate]. X-Ray structure analyses show that these complexes all exhibit pairs of infinite, unexpected, cationic and anionic chains. It is the first successful attempt to construct unprecedented NaI-CuII-LnIII heterometallic coordination polymers with both infinite cationic and anionic chains. These four complexes show homologous thermal stabilities. The different magnetic properties of are also been reported in this paper.     

Manganese(II) coordination polymers with mixed azide and pyridylbenzoate N-oxide ligands: structures and magnetism

Two novel Mn(II) coordination polymers with azide and 4-(4-pyridyl)benzoic acid N-oxide (4,4-Hopybz) were synthesized and structurally and magnetically characterized. They are formulated as {[Mn(2)(4,4-opybz)(2)(N(3))(2)(H(2)O)(2)]·H(2)O}(n) (1) and {[Mn(4)(4,4-opybz)(5)(N(3))(H(2)O)(8)](N(3))(2)·2H(2)O}(n) (2). Compound 1 contains 2D coordination layers in which the infinite Mn(II) chains with alternating (μ-EO-N(3))(2)(μ-COO) (EO = end-on) and (μ-COO)(μ-O) bridges are interlinked by the backbones of the organic ligands. Compound 2 is a 3D metal-organic framework in which the unique linear tetranuclear clusters with (μ-EO-N(3))(μ-COO) and (μ-COO)(μ-O) bridges are cross-linked by organic backbones, and it represents a new example of the rare 8-connected self-catenated 3D net with the point symbol 4(16)·6(12). Magnetic analyses on the compounds have been performed in the classical-spin approximation, revealing that all the above-mentioned mixed bridging motifs induce weak antiferromagnetic interactions between Mn(II) ions.