One-dimensional Polymeric Chains Research Articles

Synthesis, crystal structure, vibrational properties and theoretical investigation of (N,N-dimethylbenzylammonium)trichlorocadmate(II)

A novel organic–inorganic hybrid material, (C9H14N)CdCl3, was synthesized, and its structure was determined at room temperature in the non-centrosymmetric monoclinic space group Cc with the following parameters: a=13.780(5) Å, b=14.935(5) Å, c=6.768(5) Å, β=112.71(4)°, and Z=4. Its structure contained (N,N-dimethylbenzylammonium) cations and one-dimensional polymeric chains of [CdCl3-]n consisting of a face-shared CdCl6 distorted octahedral. The crystal structure was stabilized by an extensive network of NH⋯Cl hydrogen bonds between the cation and the anionic chains. The differential scanning calorimetry (DSC) of the title compound revealed an endothermic transition at 429K.The optimized geometric parameters, normal mode frequencies, and corresponding vibrational assignments of the present compound were theoretically examined by the DFT/B3LYP method with the Lanl2dz basis set. The FT-Raman and FT-IR spectra of the polycrystalline samples were examined and compared to those of the calculated spectra. The calculated results showed that the optimized geometry could well reproduce the crystal structure and that the theoretical vibrational frequency values were in good agreement with their experimental counterparts.

Gabapentin Coordination Networks: Mechanochemical Synthesis and Behavior under Shelf Conditions

Active pharmaceutical ingredients (API) coordination complexes and networks present a promising pathway for developing new bioinspired materials. In the present study, we report several coordination networks of gabapentin with Y(III), Mn(II), and several lanthanides (LnCl3), Ln = La3+, Ce3+, Nd3+, Er3+ obtained by mechanosynthesis. To the best of our knowledge, these are among the first coordination networks of pharmaceuticals involving lanthanides. These novel compounds proved to be unstable under shelf conditions, are thermally stable until water release at approximately 80 °C, and decompose above 200–250 °C. The coordination networks obtained present different structural architectures based on mono-, di-, tri-, and hexa-metallic centers (herein called monomers, dimers, trimers, and hexamers), and also a one-dimensional polymeric chain was obtained. Gabapentin chelation modes are the same in most of the networks, adopting three typical geometries: the bidentate coordination – chelation, mode I; the brid...

Hydrothermal synthesis, crystal structure of three novel complexes based on thiabendazole and 1,4-benzenedicarboxylate ligands

Three novel metal-organic complexes [Co(BDC)(TBZ)2] (I), [Cd2(BDC)2(TBZ)2(H2O)2] · 2(H2O) (II), [Mn2(BDC)(TBZ)4(SO4)] (III) (BDC = 1,4-benzenedicarboxylate, TBZ = thiabendazole) have been prepared and characterized by IR spectrum, elemental analysis, thermogravimetric analysis, and single-crystal X-ray diffraction. X-ray structure analysis reveals that both three complexes are one-dimensional chain polymers. The 1D chain architecture of I is constructed from terephthalic acid and cobalt atoms. A simultaneous presence of chelating and monodentate coordination modes of BDC ligands is observed in complex II. In complex III, the coordinated BDC ligands adopt monodentate mode and with SO42− anions alternately bridge the Mn2+ ions into 1D chains. The 3D structures of the three complexes are stabilized by π-π stacking interactions and hydrogen-bonds.

A one-dimensional coordination polymer of 5-(pyridin-2-yl)-3,3′-bi(4H-1,2,4-triazole) with Cd(NO3)2

In the title coordination polymer, catena-poly[[(methanol-κO)(nitrato-κO)cadmium(II)]-μ-3-(pyridin-2-yl)-5-(1H-1,2,4-triazol-5-yl)-4H-1,2,4-triazol-4-ido], [Cd(C9H6N7)(NO3)(CH3OH)]n, the asymmetric unit is composed of one Cd(II) centre, one nitrate anion, one deprotonated 5-(pyridin-2-yl)-3,3'-bi(4H-1,2,4-triazole) ligand, denoted HBPT(-), and one coordinated methanol molecule. Each Cd(II) ion shows an octahedral geometry and is surrounded by four N atoms from two HBPT(-) ligands in the equatorial plane, and by two O atoms from a monodentate nitrate ligand and a methanol ligand. The structure is a one-dimensional polymeric chain, which is further extended to a three-dimensional supramolecular network via a combination of hydrogen-bonding and aromatic stacking interactions.

Crystal Engineering with Modified 2-Aminopurine and Group 12 Metal Ions

This communication describes the synthesis and structure of zinc, cadmium, and mercury complexes of modified N9-substituted 2-aminopurine (2AP) analogues. 2AP is an inherently fluorescent heterocyclic nucleobase with wide applications in biochemical reactions. Herein, we report a one-dimensional (1D) polymeric helical chain and discrete arrangements for zinc complexes [C8H11N5Cl2Zn] (1) and [C12H15N5O5Zn] (2), a 1D polymeric helical chain for a Cd complex [C8H11CdI2N5] (3), and a unique example of supported 2AP-Hg(II) two-dimensional clusters [C16H21Cl6Hg3N10] (4). The photoluminescence properties of free ligand L and complexes 1–4 are also presented.

Synthesis, crystal structures and magnetism of two coordination compounds constructed from 2,5-disulfonylterephthalate ligand

Two coordination compounds with novel sulfonate–carboxylate ligand of 2,5-disulfonylterephthalate acid (H4DSBDC), namely, [Ni(2,2′-bpy)(H2O)4](DSBDC)0.5 (1) and [Mn(DSBDC)0.5(2,2′-bpy)(H2O)2]n (2) (2,2′-bpy=2,2′-bipyridyl), have been synthesized. In situ formation of H4DSBDC ligand derived from 5-sulfonyl-1,2,4-benzenetricarboxylic acid is unprecedented and involves a fundamentally new substitution of sulfonate for carboxylate to in situ ligand synthesis reaction. Compound 1 has a mononuclear nickel [Ni(2,2′-bpy)(H2O)4]2+ motif charged with tetraanionic DSBDC4− ion. The [Ni(2,2′-bpy)(H2O)4] cations and DSBDC4− anions are linked by extensive hydrogen bonds to form a three-dimensional supramolecular structure. Compound 2 is a one-dimensional polymeric chain based on the dinuclear Mn2 units. The one-dimensional chains are linked by hydrogen bonds and π–π interactions to form a three-dimensional supramolecular structure. The temperature-dependent magnetic susceptibility data of 1 and 2 have been investigated. The Curie constant C and Weiss constant θ are 1.29 cm3Kmol−1 and −1.61K for compound 1, respectively, revealing antiferromagnetic interactions between the Ni(II) ions. The magnetic data of 2 are fitted with the dinuclear Mn2 model giving the best fitting results of g=2.04, J=−0.68, and zj′=−0.016cm−1, which indicate the antiferromagnetic interactions are present in 2.

Four new metal–organic complexes by tuning the spacer length of flexible bis-pyridyl–bis-amide ligands: Assembly, structures and properties

Four new metal–organic complexes based on four flexible bis-pyridyl–bis-amide ligands with different spacer length and 1,3-benzenedicarboxylic acid, namely [Ni(3-dpye)(1,3-BDC)(H2O)2] (1), [Ni(3-dpyp)(1,3-BDC)(H2O)]·H2O (2), [Ni(3-dpyb)(1,3-BDC)(H2O)2]·H2O (3), [Ni(3-dpyh)(1,3-BDC)(H2O)2]·H2O (4) [3-dpye = N,N′-bis(3-pyridinecarboxamide)-1,2-ethane, 3-dpyp = N,N′-bis(3-pyridinecarboxamide)-1,3-propane, 3-dpyb = N,N′-bis(3-pyridinecarboxamide)-1,4-butane, 3-dpyh = N,N′-bis(3-pyridinecarboxamide)-1,6-hexane, 1,3-H2BDC = 1,3-benzenedicarboxylic acid], have been hydrothermally synthesized and structurally characterized by elemental analyses, IR, PXRD, TG and single crystal X-ray diffraction analyses. X-ray analyses reveal that the title complexes show three different two-dimensional (2D) coordination layers (for complexes 1, 3 and 4) and a one-dimensional (1D) polymer chain (for complex 2). In four Ni(II) complexes, the four flexible bis-pyridyl–bis-amide ligands only show a μ2-bridging mode. While the 1,3-BDC ligands adopt two kinds of coordination modes in these four complexes: a bis(monodentate) bridging mode with each carboxyl group in a μ1-η1:η0 mode in complexes 1, 3 and 4, a chelating-monodentate bridging mode with one carboxyl group in a μ1-η1:η1 mode and another carboxyl group in a μ1-η1:η0 mode in 2. Finally, the adjacent 2D layers or 1D chains are further extended into 3D supramolecular frameworks via hydrogen bonding or π–π stacking interactions. The spacer length and conformation of the bis-pyridyl–bis-amide ligands play an important role in the final structures of the title complexes. The fluorescent and electrochemical properties of complexes 1–4 have also been investigated.

Dimeric Ni(II)2 and polymeric Ni(II)4Fe(II) type complexes bridged with Cl− and CN− ligands: X-ray structures and magnetic properties of a dimeric complex of [(tren)Ni(μ-Cl)2Ni(tren)](ClO4)2 and a polymeric complex of {[Fe(CN)6][Ni(tren)]2[Ni(tren)(H2O)]2}Cl2(ClO4)2·4H2O

Abstract A dimeric complex of [(tren)Ni(μ-Cl)2Ni(tren)](ClO4)2 (1) and a polymeric complex of {[Fe(CN)6][Ni(tren)]2[Ni(tren)(H2O)]2}Cl2(ClO4)2·4H2O (2), are isolated from the reaction of potassium ferricyanide, nickel chloride and tren and their X-ray structures and magnetic properties were characterized. Two [Ni(tren)]2 + units are linked through bis μ-Cl ligands forming dimeric structure of 1. In complex 2, there are two kinds of Ni(II) unit, terminal ([Ni(tren)(H2O)]2 +) and bridged ([Ni(tren)]2 +), and this bridged [Ni(tren)]2 + units are linked with two different Fe(II) ions through μ-NC ligands forming one-dimensional polymeric rectangular chain. 1 shows a weak ferromagnetic coupling between two Ni(II) ions and 2 shows spin crossover in Fe(II) ion.

Supramolecular assemblies and magnetic behaviors of the M(II)/p-aminopyridine/malonate (M = Ni, Mn, Cu, Co) systems

The coordination compounds [Ni(μ-mal)(apy)2(H2O)]·2.8H2O (1), [Mn(μ-mal)(H2O)2] (2), (apyH)2[Cu(μ-mal)2] (3) and (apyH)2[Co(mal)2(H2O)2] (4) (mal=malonate, apy=p-aminopyridine) have been synthesized and characterized by elemental analysis, vibrational spectroscopy, single crystal X-ray diffraction and magnetometry. With exception of 4, the malonate group acts as bridging ligand leading to the formation of one-dimensional polymeric chains. In compound 1 it was observed the coordination of the p-aminopyridine in the axial positions of the distorted octahedral coordination sphere. The solid-state structure exhibits a high complex 3D network formed by several supramolecular interactions. Magnetic properties were determined for all members of the series and indicate that the materials behave are normal paramagnets, except the Mn polymer 2 which exhibits an antiferromagnetic ground state.

Some new compounds with P(E)NHC(O) (E = lone pair, O, S) linkage: synthesis, spectroscopic, crystal structures, theoretical studies, and antimicrobial evaluation

New phosphinoamides, chalcogenides, and amidophosphates were synthesized and characterized by 1H, 13C, 31P NMR, IR spectroscopy, and elemental analysis. The 13C NMR spectra of two phosphinoamides exhibit obvious differences between their 1 J(P,C) coupling constants (128.3 Hz in one compound vs. 439.2 Hz in another compound). Natural bond orbital analysis was performed to clarify the electronic behavior of the title molecules. The crystal structures of three derivatives were determined by X-ray crystallography. The structure of N-(Diphenylphosphino)-2-pyrazinecarboxamide contains two symmetry-independent forms of the molecule with equal occupancy in the lattice. Density functional theory calculations indicate that two conformers of this compound are identical from an energy point of view. Strong intermolecular N–H···O(P) hydrogen bonds lead to a centrosymmetric dimer in Diphenyl N-(2-pyrazinylcarbonyl)phosphoramidate, whereas N–H···(O)C and N–H···N hydrogen bonds in N-(Diphenylphosphino)-2-pyrazinecarboxamide and N-(Diphenylphosphinothioyl)-2-pyrazinecarboxamide sulfide, respectively, form a one-dimensional polymeric chain in their structures. The in vitro antimicrobial activity of the amidophosphates was evaluated against various microbial strains of Gram positive and Gram negative bacteria and fungi.

4-hydroxy-2H-1,2-benzothiazine-3-carbohydrazide 1,1-dioxide-oxalohydrazide (1:1): X-ray structure and DFT calculations

The title compound, 4-hydroxy-2H-1,2-benzothiazine-3-carbohydrazide 1,1-dioxide-oxalohydrazide (1:1), is determined using X-ray diffraction techniques and the molecular structure is also optimized at the B3LYP/6-31G(d,p) level using density functional theory (DFT). The asymmetric unit consists of four independent molecules. The oxalohydrazide molecules have the centre of symmetry at the mid-point of the central C-C bond. Each thiazine ring adopts a half-chair conformation. Intermolecular C-H...O, N-H...O and N-H...N hydrogen bonds produce R22 (10), R22 (13), R33 (12) and R33 (15) rings, which lead to one-dimensional polymeric chains. An extensive three-dimensional supramolecular network of N-H...N, N-H...O, C-H...O and O-H...O hydrogen bonds is responsible for crystal structure stabilization.

Metal-to-Ligand Ratio As a Design Factor in the One-Pot Synthesis of Coordination Polymers with [MS4Cun] (M = W or Mo, n = 3 or 5) Cluster Nodes and a Flexible Pyrazole-Based Bridging Ligand

Two complexes, [WS4Cu5I3(bbd)2]n (1) and [(WS4Cu3I)2(bbd)3]n·n(DMF) (2), with one-dimensional polymeric chain structures containing hexanuclear and tetranuclear clusters linked by flexible 1,4-bis(3,5-dimethylpyrazol-1-yl)butane (bbd) ligands have been synthesized in facile one-pot reactions at room temperature, together with the molybdenum analogue of 2. The only significant difference in the syntheses of the two tungsten complexes is the 5:1 or 3:1 molar ratio of copper(I) to [WS4]2–, the other experimental factors being kept constant. The observed products reflect the stoichiometric Cu:W ratio used. All three complexes were characterized by IR and UV–vis spectroscopy, thermal and elemental analyses, and single-crystal X-ray diffraction. Complex 1 contains an unusual and surprisingly unsymmetrical WS4Cu5I3 cluster in which five Cu atoms bridge all but one of the six S···S edges of the WS4 tetrahedron and the three I atoms all have different coordination modes (terminal, μ2 and μ3); it consists of two face-sharing WS3Cu3I distorted cubes, in one of which a Cu···I edge is opened up instead of being bonded, this Cu atom (shared by the two cubes) having an additional terminal iodo ligand. Complex 2 is the first reported example of a polymer containing (S=)MS3M′3X cubes linked by organic ligands; pairs of these cube clusters are connected by pairs of bbd ligands, and the (cluster)2(bbd)2 units are assembled into chains by single bbd bridges. In these and previously reported complexes, the bbd bridging ligand displays considerable flexibility, enabling it to support a range of discrete oligomeric and polymeric structures. X-ray powder diffraction shows that 2 is consistently obtained as a mixture of two polymorphs, and the same has been found for the corresponding molybdenum complex [(MoS4Cu3I)2(bbd)3]n·n(DMF) (3), for which the second polymorph has been structurally characterized by single-crystal diffraction using synchrotron radiation. The two polymorphs have essentially identical polymer chain structures, with different packing arrangements of the chains and different symmetry properties.

Torsional effects on the optical properties of PPV and PPP

The optical properties of infinite and isolated chains of poly(para-phenylene vinylene) (PPV) and poly(para-phenylene) (PPP) are studied using Density Functional Theory (DFT) in the Local Density Approximation (LDA) with norm-conserving pseudopotentials to replace the core electrons. We investigate theoretically the influence of several structural modifications of conjugated polymers on the band gap and the optical properties. Our results show that the band gap for isolated chains of PPV depends on the chain length. We also find that for both PPV and PPP one-dimensional chain polymers, the optical properties are strongly affected by the torsion angles.

Hydrothermal Synthesis and Crystal Structures of Three Novel Cobalt(II) Complexes Based on Thiabendazole Ligand

Three novel metal–organic complexes, [Co(BDC)(TBZ)] (1), [Co2(PDA)2(H2O)(TBZ)2] (2), and [Co(HBTC)(TBZ)(H2O)] (3) (where BDC = 1,4-benzenedicarboxylate; PDA = 1,4-phenylendi- acetate; TBZ = thiabendazole; BTC = 1,3,5-benzenetricarbox- ylate), have been prepared and characterized by IR spectrum, elemental analysis, thermogravimetric analysis, and single-crystal X-ray diffraction. Both 1 and 3 are one-dimensional chain polymers, where two complexes are constructed from multicarboxylates and cobalt atoms. Complex 2 is a two-dimensional network polymer, where two cobalt ions are bridged by an aqua molecule and two carboxylate anions. The 3D structures of the three complexes are stabilized by π-π stacking interactions and hydrogen-bonds.

Two chiral mononuclear and one-dimensional cadmium(II) complexes constructed by (1R,2R)-N1,N2-bis(pyridinylmethyl)cyclohexane-1,2-diamine derivatives: Effect of positional isomerism

Reactions of (1R,2R)-N1,N2-bis(pyridinylmethyl)cyclohexane-1,2-diamine derivatives, (1R,2R)-2-bpcd and (1R,2R)-3-bpcd [(1R,2R)-2-bpcd = (1R,2R)-N1,N2-bis(pyridin-2-ylmethyl)cyclohexane-1,2-diamine, (1R,2R)-3-bpcd = (1R,2R)-N1,N2-bis(pyridin-3-ylmethyl)cyclohexane-1,2-diamine], with CdI2 in an analogous way led to the formation of a chiral discrete mononuclear complex and a chiral one-dimensional polymeric chain, respectively, which may be attributed to the positional isomerism of the ligands. The chiral organic ligands and complexes display luminescent properties indicating that they may have a potential application as optical materials. Powder second-harmonic generation (SHG) efficiency measurement shows that the SHG efficiency of the complexes is approximately 0.3 and 0.45 times that of KDP, respectively.

Tetra-methyl-ammonium hydrogen terephthalate.

The asymmetric unit of the title salt, C4H12N+·C8H5O4 −, contains one half of a tetra­methyl­ammonium cation and one half of a hydrogen terephthalate monoanion. The N atom of the ammonium cation lies on a twofold rotation axis and the centre of mass of the terephthalate anion is on a centre of inversion. In the crystal, the centrosymmetric terephthalate ions are linked by a very short symmetric O—H⋯O hydrogen bond [O⋯O = 2.4610 (19) Å] into a one-dimensional polymeric chain along [1-12]. The tetra­methyl­ammonium cations and terephthalate anions are then connected through a pair of bifurcated acceptor C—H⋯O hydrogen bonds, generating a three-dimensional supra­molecular network. The carboxyl­ate groups at both ends of the terephthalate anion are charge-shared with an equal probability of 0.5.

Directional motion of forced polymer chains with hydrodynamic interaction

We study the propulsion of a one-dimensional (1D) polymer chain under sinusoidal external forces in the overdamped (low Reynolds number) regime. We show that, when hydrodynamical interactions are included, the polymer presents directional motion which depends on the phase differences of the external force applied along the chain. Moreover, the velocity shows a maximum as a function of the frequency. We discuss the relevance of all these results in light of recent nanotechnology experiments.

Hydrothermal Synthesis, Crystal Structure of Four Novel Complexes Based on Thiabendazole Ligand

Four novel metal-organic complexes (1), (2), (3), [Co(PDC)(TBZ)] (4) (where IP = isophthalate; TBZ = thiabendazole; BTC = 1,3,5-benzenetricarboxylate; PDC = pyridine-3,4-dicarboxylate) have been prepared and characterized by IR spectrum, elemental analysis, thermogravimetric analysis, and single-crystal X-ray diffraction. X-ray structure analysis reveals that 1, 2, and 3 are one-dimensional chain polymers, while 4 is a two-dimensional network polymer. The TBZ acts as a typical chelating ligand coordinated to the metal center in all complexes. The 1D chain architecture of 1 is constructed from isophthalates and cadmium atoms. A simultaneous presence of chelating, monodentate and bidentate coordination modes of IP ligands is observed in complex 2. In complex 3, the 16-membered rings are alternately arranged forming an infinite 1D double-chain structure. The 2D skeleton of 4 is formed by cobalt ions as nodes and PDC dianions as spacers, through coordination bonds. The hydrogen bonds and stacking play important roles in affecting the final structure where complexes 1 and 3 have 2D supramolecular networks, while complexes 2 and 4 have 3D supramolecular architectures.

2-Propyl-4,5-dicarboxylate-imidazole (H3PIDC) Based Cadmium(II) Coordination Compounds Stabilized by Supramolecular Interactions: From Mononuclear and Tetranuclear Oligomers to One-Dimensional (1D) Chain and Two-Dimensional (2D) Layer Polymers

Six cadmium(II) coordination compounds with 2-propyl-imidazole-4,5-dicarboxylate (H3PIDC), including two mononuclear complexes, [Cd(H2PIDC)2(H2O)2]·4H2O (1) and [Cd2(H2PIDC)4(H2O)4]·7H2O (2), two square tetranuclear complexes, [Cd4(HPIDC)4(H2O)8]·2H2O (3) and [Cd4(HPIDC)4(py)8]·10H2O (py = pyridine, 4), one one-dimensional chain polymer, [Cd2(H2PIDC)4(H2O)2]n·2nH2O (5), as well as one two-dimensional layer polymer, [Cd(H2PIDC)2]n (6), have been prepared using solvent evaporation method and hydrothermal method. The results of single-crystal X-ray diffraction analyses indicate that, besides the common supramolecular interactions such as hydrogen bond and π···π stacking, the hydrophobic interaction among the propyl groups in the H3PIDC ligands also contributes to the stabilities of 1–6. The study of substance transformation for 3 reveals that the coordinated H2O molecules in 3 can be well replaced by pyridine molecules, indirectly leading to the formation of 4. The results of photoluminescent measurements illustrate upon photoexcitation that 3–6 can emit fluorescence in the wavelength range of 451–473 nm in the solid state.

Building-up Remarkably Stable Magnesium Porphyrin Polymers Self-Assembled via Bidentate Axial Ligands: Synthesis, Structure, Surface Morphology, and Effect of Bridging Ligands

A series of supramolecular architectures of magnesium tetranitrooctaethylporphyrins mediated by several bidentate axial ligands have been synthesized in excellent yields and structurally characterized. Six conjugated axial ligand with increasing chain lengths have been utilized in the present investigations in which the Mg···Mg nonbonding distance between successive ions also increases from 0.73 to 2.70 nm in the series. To the best of our knowledge, this is the first report where stable metallo-porphyrin polymers with such long spacers have been synthesized in one pot so easily. Linear one-dimensional (1D) polymeric chains were observed in the X-ray structure of the six-coordinated complexes in which porphyrin units are aligned parallel to each other to have so-called "shish kebab" like architectures to maintain offset-stacked overlap. However, after an optimum Mg···Mg nonbonding distance, these 1D chain do not continue, rather they form five-coordinated porphyrin dimers with "wheel-and-axle" like architectures which are then self-aggregated by π-π interactions in a perpendicular manner to fill space created by large bridging ligands more effectively which consequently results in spherical structures. The structures of the molecules in solution and their surface patterns on highly ordered pyrolytic graphite (HOPG) have also been investigated.