Polymeric Zigzag Research Articles

Crystal structure of an HgII coordination polymer with an unsymmetrical dipyridyl ligand: catena-poly[[[di-chlorido-mercury(II)]-μ-N-(pyridin-4-ylmeth-yl)pyridin-3-amine-κ2N:N'] chloro-form hemisolvate

The asymmetric unit of the title compound, {[HgLCl2]·0.5CHCl3} n (L = N-(pyridin-4-ylmeth-yl)pyridin-3-amine, C11H11N3), contains one HgII ion, one bridging L ligand, two chloride ligands and a chloro-form solvent mol-ecule with half-occupancy that is disordered about a crystallographic twofold rotation axis. Each HgII ion is coordinated by two pyridine N atoms from two symmetry-related L ligands and two chloride anions in a highly distorted tetra-hedral geometry with bond angles falling in the range 99.05 (17)-142.96 (7)°. Each L ligand bridges two HgII ions, forming polymeric zigzag chains propagating in [010]. In the crystal, the chains are linked by inter-molecular N/C-H⋯Cl hydrogen bonds together with weak C-H⋯π inter-actions, resulting in the formation of a three-dimensional supra-molecular network, which is further stabilized by C-Cl⋯π inter-actions between the solvent chloro-form mol-ecules and the pyridine rings of L [chloride-to-centroid distances = 3.442 (11) and 3.626 (13) Å]. In addition, weak Cl⋯Cl contacts [3.320 (5) Å] between the chloro-form solvent mol-ecules and the coordinating chloride anions are also observed.

Synthesis, characterization and self-assembly of three dicyanamide bridged polynuclear copper(II) complexes with N2O donor tridentate Schiff bases as blocking ligands

Three copper(II) complexes [Cu(L1)(μ1,5-dca)]n (1), [Cu(L2)(μ1,5-dca)]n (2) and [Cu(L3)(μ1,5-dca)]n (3) [where HL1=(1-(2-(dimethylamino)ethylimino)ethyl) naphthalene-1-ol, HL2=(1-(2-(methylamino)ethylimino)ethyl) naphthalene-1-ol and HL3=(1-(2-(ethylamino)ethylimino)ethyl)naphthalene-1-ol] have been synthesized and characterized by elemental analysis, IR and UV–Vis spectroscopy. The structure of each complex has been confirmed by single-crystal X-ray diffraction studies. In all three complexes, copper(II) centres are bridged by dicyanamide in end to end fashion. Complexes 1 and 2 are zigzag polymers, whereas complex 3 is a helical one. The weak forces like C–H⋯π and π⋯π interactions influence the self-assembly process in all three complexes. Such types of interactions lead to the formation of interesting supra molecular networks in three complexes.

CB-TE2A(+)·Cl(-)·3H2O: a short intermolecular hydrogen bond between zwitterionic bicyclo[6.6.2]tetraamine macrocycles.

1,4,8,11-Tetraazabicyclo[6.6.2]hexadecane-4,11-diacetic acid (CB-TE2A) is of much interest in nuclear medicine for its ability to form copper complexes that are kinetically inert, which is beneficial in vivo to minimize the loss of radioactive copper. The structural chemistry of the hydrated HCl salt of CB-TE2A, namely 11-carboxymethyl-1,8-tetraaza-4,11-diazoniabicyclo[6.6.2]hexadecane-4-acetate chloride trihydrate, C16H31N4O4(+)·Cl(-)·3H2O, is described. The compound crystallized as a positively charged zwitterion with a chloride counter-ion. Two of the amine groups in the macrocyclic ring are protonated. Formally, a single negative charge is shared between two of the carboxylic acid groups, while one chloride ion balances the charge. Two intramolecular hydrogen bonds are observed between adjacent pairs of N atoms of the macrocycle. Two intramolecular hydrogen bonds are also observed between the protonated amine groups and the pendant carboxylate groups. A short intermolecular hydrogen bond is observed between two partially negatively charged O atoms on adjacent macrocycles. The result is a one-dimensional polymeric zigzag chain that propagates parallel to the crystallographic a direction. A second intermolecular interaction is a hydrogen-bonding network in the crystallographic b direction. The carbonyl group of one macrocycle is connected through the three water molecules of hydration to the carbonyl group of another macrocycle.

Copper(I) oligomers and polymers with dicyanobenzene and cyanopyridine ligands

The reaction of [Cu(MeCN)4]BF4 with o-, m-, or p-dicyanobenzene (DCB) or o-, m-, or p-cyanopyridine (CPy) in the presence of two equivalents of PPh3 produces DCB- or CPy-bridged copper(I) complexes. Cyclic dimers are formed for the ortho ligands, and zigzag polymers are formed using the para ligands. m-DCB produces a polymer, however m-CPy results in a cyclic trimer. Multiple lattice-bound solvates are formed upon crystallization of the o-DCB dimer from various solvents. A total of 11 X-ray crystal structures are reported for [Cun(PPh3)2n(bridge)n](BF4)n·(solvent): bridge=o-DCB, n=2, solvent (per dimer)=none, ½ CH2Cl2, CH2Cl2, 2 CHCl3/H2O, or 2 THF; bridge=m-DCB, n=∞, solvent=none; bridge=p-DCB, n=∞, solvent=CH2Cl2 (two polymorphs), bridge=o-CPy, n=2, solvent (per dimer)=2 toluene; bridge=m-CPy, n=3, solvent=none; bridge=p-CPy, n=∞, solvent=½ acetone. All complexes are photoluminescent with excitation in the range 340–400nm. The meta complexes emit in the blue region, while the other complexes emit in the green. Dimer complexes of o-DCB exhibit structural flexibility in the central macrocyclic ring. Complexes of m-DCB and p-CPy show orientational disorder in the ligand. Polymeric complexes show helicity. Smaller Stokes shifts are noted for DCB than for CPy complexes, suggesting less excited state distortion for cyanoaromatic ligand complexes of Cu(I).

Preparation, structural organization, and thermal behavior of the ion-polymeric gold(III)–zinc(II)–dibutylammonium complex ([NH2(C4H9)2][Au{S2CN(C4H9)2}2][ZnCl4)] n

Structural organization and thermal behavior of a new polymeric heteronuclear of gold(III)-zinc-dibutylammonium complex ([NH2(C4H9)2][Au{S2CN(C4H9)2}2][ZnCl4])n (I), obtained by a heterogeneous reaction between freshly precipitated binuclear zinc dibutyldithiocarbamate [Zn2{S2CN(C4H9)2}4] and a H[AuCl4] solution in 2M HCl, is studied. According to single crystal XRD data the crystal structure of the obtained compound is determined and its main structural units are complex [NH2(C4H9)2]+ and [Au{S2CN(C4H9)2}2]+ cations and complexе [ZnCl4]2– anions. Dibutylammonium cations are hydrogen bonded to tetrachlorozincate ions, forming zigzag polymer chains. On the side of the chains there are discrete complex [Au{S2CN(C4H9)2}2]+ cations characterized by a planar tetragonal structure and a uniform spatial orientation. The thermal behavior of I is investigated by synchronous thermal analysis. The multistage process of thermal destruction involves the thermolysis of the cation and anion parts (with the release of metallic gold, zinc chloride and a partial formation of zinc sulfide).

Hydrogen-bonded hexameric cluster of benzyl alcohol in the solid state polymeric organization of p-tert-Butylcalix[5]arene

An uncommon hydrogen-bonded hexameric cluster of benzyl alcohol (2) was formed in hydrophobic space in the layered organisation of the one-dimensional polymeric zigzag array of 1 in the solid state. The hexameric cluster adopted a distorted cyclohexane-like (12) O–H⋯O hydrogen bond network. The formation of the hexameric cluster was quite sensitive to a tiny structural difference of guests; phenylethylalcohol (3), phenol (4), benzyl amine (5) and aniline (6) did not form any hexameric cluster. The packing coefficient of 0.53 suggested that the hexameric cluster nicely filled the hydrophobic space, which most likely resulted in the effective van der Waals contacts that stabilised the supramolecular organisation composed of the hexameric cluster and the polymeric array of 1 in the solid state.

Syntheses and X-ray structures of heteroleptic octahedral Mn(II)-xanthato complexes involving N-donor ligands

A series of octahedral manganese(II) complexes involving xanthates and N-donor ligands, [Mn(S2COiBu)2(phen)] (1), [Mn(S2COiBu)2(2,2′-bpy)] (2), [Mn(S2COnPr)2(phen)] (3), [Mn(S2COnPr)2(2,2′-bpy)] (4), [Mn(S2COMe)2(2,2′-bpy)] (5), [Mn(S2COnPr)2(4,4′-bpy)]n, and [Mn2(S2COnPr)4(4,4′-bpy)3] (6) (phen = 1,10-phenanthroline, bpy = bipyridine) was prepared. Complexes were characterized by elemental analysis, FTIR spectroscopy, TG/DSC analysis, and single-crystal X-ray diffraction. The structures are built of monomeric molecules of the complexes, except for 6 with the 4,4′-bipyridine ligand, which contains a binuclear complex and 1D polymeric zigzag chain in one crystal.

Synthesis and characterization of main‐chain, second‐order, nonlinear optical polyurethanes with isolation moieties and zigzag structures

ABSTRACTIn this study, two main‐chain second‐order nonlinear optical (NLO) polyurethanes were successfully prepared with indole‐based chromophores. The introduced phenyl isolation group and the continuous zigzag polymer backbone were found to be helpful for effectively decreasing the intermolecular dipole–dipole interactions and enhancing the NLO properties of the resulting polymers. The studied polymers exhibited good optical transparency, high thermal stability, and excellent NLO effects; this indicated that the nonlinearity–stability trade‐off and nonlinearity–transparency trade‐off could be alleviated by this newly designed polymer system. Poly{4‐anilinocarbonyl[N‐ethoxyl‐5‐phenyl‐3‐azo(2′‐oxyethylene‐4′‐nitrobenzene)indole]carbonylimino} with a zigzag backbone showed a large second harmonic generation coefficient (d33) value of 88.4 pm/V. However, poly{5‐naphthyliminocarbonyl[N‐ethoxyl‐5‐phenyl‐3‐azo(2′‐oxyethylene‐4′‐nitrobenzene)indole]carbonylimino} (PUAZN) with a continuous zigzag structure exhibited a higher d33 value of 116.2 pm/V, which was attributed to the unique rigid and zigzag linkage of 1,5‐naphthalene as the isolation spacer. The enhanced NLO efficiency and relatively longer term temporal stability made PUAZN as a promising candidate for practical applications in photonic devices. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 42974.

Anion and Cation Effects on Anion-Templated Assembly of Tetrahydroxytriptycene

A tetrahydroxytriptycene ligand 1 assembles through O–H···anion hydrogen bonds into a range of different structures. With tetrabutylammonium bromide, 1 forms a stable nanotube structure that is supported by O–H···anion hydrogen bonds, but its space is occupied by the large cation. In an effort to produce the nanotubes with different cations and anions, 1 was crystallized with different salts. The reaction of 1 with tetraethylammonium bromide gives a 2D net structure, while 1 and tetrapropylammonium bromide give a discrete 1:2 complex. Attempting to co-crystallize 1 and tetramethylammonium bromide gave crystals of an oxidized quinone form of the ligand. When 1 was crystallized with tetrabutylammonium terephthalate, two different one-dimensional anion coordination polymers were obtained, depending on the crystallization solvent: acetonitrile gave a zigzag polymer, while methanol gave a linear structure. In both cases, the tetrabutylammonium cations fill the gaps between the 1D polymers, giving a layered 2D ...

Silver complexes of symmetrically 4,5-disubstituted 3,6-di(3,5-dimethyl-1H-pyrazol-1-yl)pyridazine

The reaction of ligands based on 3,6-di(3,5-dimethyl-1H-pyrazol-1-yl)pyridazine having carbocyclic rings fused to the pyridazine ring; 1,4-bis(3,5-dimethylpyrazol-1-yl)-6,7-dihydro-5H-cyclopenta[d]pyridazine (L1), 1,4-bis(3,5-dimethylpyrazol-1-yl)-5,6,7,8-tetrahydrophthalazine (L2) and 7,10-bis(3,5-dimethyl-1H-pyrazol-1-yl)-8,9-diazafluoranthene (L3) with silver triflate gave complexes 1–3. Characterisation of these using single-crystal X-ray structure determination clearly showed that the steric bulk of the carbocycle stops the 3,5-dimethyl-1H-pyrazole from chelating metal atoms. Ligands L1 and L3 were tetrabridging (complexes 1 and 3), while L2 formed a one-dimensional zigzag polymer (complex 2).

Surface-Confined Synthesis of One-Dimensional Schiff Base Polymers Investigated by Scanning Tunneling Microscopy

The surface-mediated synthesis of ordered linear or zigzag polymers on a highly oriented pyrolytic graphite surface was investigated either at a solid/liquid interface or with moderate heating under low vacuum. Scanning tunneling microscopy (STM) reveals the submolecular details of the structure and growth dynamics of surface-confined one-dimensional polymers. We discovered that the substituent and concentration of monomers have a significant effect on the assembling structure of the in-situ-synthesized one-dimensional polymer at the octanoic acid/graphite interface.

Crystal structure of poly[[μ-1,1'-(butane-1,4-di-yl)bis-(1H-benzimidazole)-κ(2) N (3):N (3')]{μ-4,4'-[1,4-phenyl-enebis(-oxy)]di-ben-zo-ato-κ(4) O,O':O'',O'''}cobalt(II)

In the title compound, [Co(C20H12O6)(C18H18N4)]n, the CoII atom, located on a twofold rotation axis, is hexa­coordinated to four O from two bis-bidentate 4,4′-[phenyl­enebis(­oxy)]dibenzoate (L) ligands and two N atoms from two 1,1′-(butane-1,4-di­yl)bis­(1H-benzimidazole) (bbbm) ligands, forming a distorted octahedral cis-N2O4 coordination environment. Polymeric zigzag chains along [102] are built up by the bridging L ligands. These chains are additionally connected by the bbbm ligands to produce a two-dimensional coordination polymer parallel too (010).

Synthesis and characterization of macrocyclic and polymeric Schiff base complexes derived from related macrocyclic ligands in the presence of Ni(II) and Cu(II)

Four macrocyclic Schiff base ligands (L1, L2, L3, and L4) have been prepared. In the presence of Copper(II), original macrocycles were converted to the three new binuclear polymeric complexes [Cu2L 2 1′ ](NO3)2, [Cu2L 2 2′ ](NO3), and [Cu2L 2 3′ ](NO3)2. But in the presence of Nickel(II), macrocyclic rings remained unchanged and Schiff base complexes of [NiL1(CH3CN)2(CH3OH)2](ClO4)2 and [NiL4](NO3)2 were synthesized. All ligands and their related complexes were characterized by elemental analysis, IR spectroscopy, in the case of ligands 1H, 13C NMR and EI-Mass and for [Cu2L2′](NO3)2 and [NiL1(CH3CN)2(CH3OH)2](ClO4)2 complexes X-ray crystal structure determination have been performed. Crystal structure showed 1D zigzag polymer for [Cu2L 2 1′ ](NO3)2 and macrocyclic structure for [NiL1(CH3CN)2(CH3OH)2](ClO4)2 complexes. The ligands and related polymeric complexes were screened for their antibacterial activities against six bacterial strains and the complexes showed antibacterial effects.

Crystal structure of tetra-butyl-ammonium bromide-1,2-di-iodo-3,4,5,6-tetra-fluoro-benzene-di-chloro-methane (2/2/1).

The crystallization of a 1:1 molar solution of 1,2-di­iodo-3,4,5,6-tetra­fluoro­benzene (o-DITFB) and tetra­butyl­ammonium bromide (n-Bu4NBr) from di­chloro­methane yielded pure white crystals of a halogen-bonded compound, C16H36N+·Br−·C6F4I2·0.5CH2Cl2 or [(n-Bu4NBr)(o-DITFB)]·0.5CH2Cl2. The compound may be described as a quaternary system and may be classified as a salt–cocrystal solvate. The asymmetric unit contains one mol­ecule of solvent, two o-DITFB mol­ecules, two cations (n-Bu4N+) and two crystallographically distinct bromide ions [θI ⋯ Br- ⋯ I = 144.18 (1) and 135.35 (1)°]. The bromide ion is a bidentate halogen-bond acceptor which inter­acts with two covalently bonded iodines (i.e. halogen-bond donors), resulting in a one-dimensional polymeric zigzag chain network approximately along the a axis. The observed short contacts and angles are characteristic of the non-covalent inter­action [d C—I⋯Br = 3.1593 (4)–3.2590 (5) Å; θC—I⋯Br = 174.89 (7) and 178.16 (7)°]. It is noted that iodine acts as both a halogen-bond donor and a weak CH hydrogen-bond acceptor, while the bromide ions act as acceptors for weak CH hydrogen bonds and halogen bonds.

The role of steric constraints in the formation of rare aqua bridged coordination polymers: Synthesis, characterization and X-ray structures of polymeric, [Cu(2-chlorobenzoate)2(β-picoline)2(μ-H2O)]n and monomeric, [Cu(2-chlorobenzoate)2(γ-picoline)2(H2O)

Reaction of hydrated copper(II) 2-chloro-benzoate with β-/γ-picoline in methanol: water mixture (4:1 v/v) yielded polymeric [Cu(2-chlorobenzoate)2(β-picoline)2(μ-H2O)]n; 1 and monomeric [Cu(2-chlorobenzoate)2(γ-picoline)2(H2O)]; 2. The newly synthesized complexes have been characterized by elemental analyses, FT-IR spectroscopy, UV–Visible spectroscopy, TGA and single crystal X-ray structure determination. X-ray crystallographic analysis revealed that both complexes crystallize in the monoclinic crystal system with space group and unit cell dimensions: C2/c; a=51.71Å, b=10.58Å, c=10.02Å and β=100.5° for 1 and P21/c; a=11.81Å, b=16.33Å, c=13.79Å and β=90.77° for 2. Whereas in 1 the presence of constituent and mediating water molecules running along a-axis gives rise to 1-dimensional zig-zag polymer chains, in complex 2, the presence of square pyramidal arrangement of ligands around copper(II) center results in monomeric structure. Various non-covalent interactions like OH⋯O, CH⋯O and CH⋯л have been observed to play a decisive role in the stabilization of crystal lattices in both complexes.

Chemisorption of gold(III) from solutions using thallium(I) diisobutyldithiocarbamate: Supramolecular structure and thermal behavior of the polymeric gold(III)-thallium(III) complex ([Au{S2CN(iso-C4H9)2}2][TlCl4]) n

Chemisorption of gold(III) from 2 M HCl using thallium(I) diisobutyldithiocarbamate via an ion exchange/redox process gives a polymeric gold(III)-thallium(III) complex of the formula ([Au{S2CN(iso-C4H9)2}2][TlCl4])n (I). Its supramolecular structure determined by X-ray diffraction (CIF file CCDC no. 1009388) comprises three structurally nonequivalent complex cations [Au{S2CN(iso-C4H9)2{2]+ (A, B, and C) and two nonequivalent [TlCl4]−-anions, both the cations and the anions being conformers. The isomeric cations are united through pairs of relatively weak secondary nonvalent Au⋯S contacts into zigzag polymer chains (⋯A⋯B⋯C⋯B⋯)n, with alternating nonequivalent [TlCl4]− anions on both sides. The thermal behavior of complex I was studied by simultaneous thermal analysis. The TG curve shows two steps of its weight loss. The first step involves thermal decomposition of the dithiocarbamate portion of the complex and [TlCl4]− with reduction of gold(III) to metallic gold and release of TlCl. The second step is due to evaporation of TlCl. The final thermolysis product of complex I is reduced metallic gold.

Synthesis of the first chalcogen-centered diselenophosphinato Zn(II) clusters, [Zn4(μ4-X){Se2PR2}6] (X = S or Se), and a zigzag polymer {ZnBr(μ-Se2PR2)[PyNO]}n

N,N-Diethylammonium diselenophosphinate, [Et2NH2][Se2PR2] (R = CH2CH2Ph), under mild conditions (r.t., CH2Cl2) reacts with ZnBr2 to afford discrete tetranuclear cluster [Zn4(μ4-Se){Se2PR2}6] in 63% yield, which consists of Se-centered distorted Zn4 tetrahedron ligated by six edge-bridged diselenophosphinato anions (μ2, μ2). In the presence of Na2S2O3 as a S2− source, this reaction provides structurally similar S-centered cluster, [Zn4(μ4-S){Se2PR2}6], in 76% yield. Finally, at the interaction of the N,N-diethylammonium diselenophosphinate with ZnBr2 and pyridine N-oxide (the reagent ratio is stoichiometric), the zigzag polymer {ZnBr(μ-Se2PR2)[PyNO]}n, bearing a “SeZnSeP” repeating chain, was formed in 84% yield.

Molecular engineering of Schiff-base linked covalent polymers with diverse topologies by gas-solid interface reaction.

The design and construction of molecular nanostructures with tunable topological structures are great challenges in molecular nanotechnology. Herein, we demonstrate the molecular engineering of Schiff-base bond connected molecular nanostructures. Building module construction has been adopted to modulate the symmetry of resulted one dimensional (1D) and two dimensional (2D) polymers. Specifically, we have designed and constructed 1D linear and zigzag polymers, 2D hexagonal and chessboard molecular nanostructures by varying the number of reactive sites and geometry and symmetry of precursors. It is demonstrated that high-quality conjugated polymers can be fabricated by using gas-solid interface reaction. The on-demanding synthesis of polymeric architectures with diverse topologies paves the way to fabricate molecular miniature devices with various desired functionalities.

New heterometallic coordination polymers based on zinc(II) complexes with Schiff-base ligands and dicyanometallates: synthesis, crystal structures, and luminescent properties

Four new d10 heterometallic coordination polymers have been obtained using three Schiff-base ligands, zinc(II) nitrate, and dicyanometallates: 1∞[{Zn3(Salen)2}{μ-Au(CN)2}2] (1); 1∞[Zn(Saldmen){μ-Ag(CN)2}]·2H2O (2); 1∞[Zn(Salampy){μ-Ag(CN)2}] (3); 1∞[Zn(Salampy){μ-Au(CN)2}] (4). The Schiff bases are obtained from condensation of salicylaldehyde with ethylenediamine (H2Salen); N,N-dimethyl-ethylenediamine (HSaldmen) and, respectively, 2-aminomethyl-pyridine (HSalampy). The dicyanometallates are K[Ag(CN)2] and K[Au(CN)2]. The compounds were characterized by X-ray single-crystal diffraction, infrared spectroscopy, UV–vis spectroscopy, and elemental analysis. In compound 1, the homotrimetallic units, {Zn3(salen)2}2+, are connected by two [Au(CN)2]− bridges, forming a 1-D double chain. In compounds 2–4, the crystal structures show polymeric zigzag chains generated by the mononuclear zinc(II) nodes and [M(CN)2]− spacers. The luminescence properties of the new heterometallic polymers have also been investigated.

Design and construction of two rare aqua bridged copper (II) coordination polymers through mixed ligand strategy: Synthesis, characterization and single crystal X-ray structure determination of [Cu(2-iodobenzoate)2(β/γ-picoline)2(μ-H2O)

Reaction of hydrated copper (II) 2-iodobenzoate with β/γ-picoline in methanol:water mixture (4:1, v/v) yielded two rare aqua bridged zig-zag polymers [Cu(2-iodobenzoate)2(β-picoline)2(μ-H2O)]n; 1 and [Cu(2-iodobenzoate)2(γ-picoline)2(μ-H2O)]n; 2. The newly synthesized complexes have been characterized by elemental analysis, FT-IR spectroscopy, UV–Vis spectroscopy and single crystal X-ray structure determination. Complex 1 crystallized in monoclinic crystal system with C2/c space group, and complex 2 crystallized in triclinic crystal system with P1‾ space group. X-ray structure determination revealed the presence of 1-dimensional chains of constituent molecules running along a-axis in both complexes. Water molecules act as bridges between constituent molecules and hence play a crucial role in 1-dimensional chain propagation in zig-zag manner. Empty channels have been observed between the zig-zag chains of complexes. Non-covalent interactions interactions such as O–H⋯O, C–H⋯O and C–H⋯π have been observed, which play a decisive role in the stabilization of crystal lattices in both complexes 1 and 2.