Infinite Water Chain Research Articles

Synthesis, structures, and one/two-photon excited fluorescence of two new Ca(II)-coordinated polymers with D-π-A ligand

Two alkaline-earth metal coordination polymers, [Ca(TAPIP)2(H2O)3]·2H2O (1) and [Ca(TAPIP)2(H2O)3]·5H2O (2), have been synthesized under hydrothermal reactions with the imidazo[4,5-f][1, 10]phenanthroline derivate D-π-A type ligand, 2-(4-(1H-1,2,4-triazol-1-yl)phenyl)-1H-imidazo[4,5-f][1, 10]phenanthroline (TAPIP). Complexes 1 and 2 crystallize in different lattice groups and are discrete coordinate structures in which the two planes of TAPIP ligands are nearly coplanar and perpendicular, respectively. Moreover, in 2 an interesting infinite water chain is captured. In exploring their one/two-photon excited fluorescence, the results show that the original ligand and 1 exhibit similar fluorescent properties while 2 gives off orange light and shows much stronger two-photon excited fluorescent properties which might result from the different torsion angles and/or stacking modes of the organic ligands.

Use of Zwitterionic Ligands in Uranyl Hybrid Materials: Explorations on the Structural Features that Control Water Ordering and Mobility

Development of novel materials for water purification and storage is reliant on our understanding of the interaction of water within solid-state materials and inspired by the high selectivity present in certain biological systems. The present study investigates the influence of zwitterionic ligands on water properties within hybrid materials through the synthesis and characterization of four novel coordination polymers built from the uranyl unit and an imidazolium dicarboxylate (Imd) linker. One of the compounds (UIM-5) hosts an infinite water chain of edge sharing hexamers and octamers of hydrogen bonded water molecules. The other three compounds (UIM-2A, 2B, 2C) make up a polymorphic system in which the guest water molecules are found in varying degrees of isolation. We further explore the expansive literature on uranyl hybrid materials to identify common water nets and possible structural features that may control water structure and properties.

Synthesis, structure and magnetic properties of four chiral Cu(II) complexes based on N-benzoyl-l-glutamic acid and different N-donor ancillary ligands

Four new chiral Cu(II) complexes, namely [Cu2(bzgluO)2(2,2′-bipy)2]·7H2O (1), {[Cu(bzgluO)(2,4′-bipy)2(H2O)]·2H2O}n (2), [Cu2(bzgluO)2(4,4′-bipy)2]n (3), {[Cu2(bzgluO)2(bpe)2]·7H2O}n (4), have been synthesized in the presence of N-donor ancillary ligands [H2bzgluO=N-benzoyl-l-glutamic acid, 2,2′-bipy=2,2′-bipyridine, 2,4′-bipy=2,4′-bipyridine, 4,4′-bipy=4,4′-bipyridine, bpe=1,2-bis(4-pyridyl)ethane]. Their structures have been determined by single-crystal X-ray diffraction analyses and further characterized by elemental analyses, IR spectra, powder X-ray diffraction (PXRD), and thermogravimetric analyses (TGA). Complex 1 exhibits a 0D discrete unit, which is extended by the π…π stacking interactions to generate 2D supramolecular layers, a 1D infinite right-handed water chain exists in the 2D layers. Complexes 2–4 are coordination polymeric networks. Complex 2 displays a 1D chain structure and is extended by the hydrogen-bonding to generate 2D supramolecular layers. Complex 3 is a 3D pillared layered framework by linking a 2D [Cu(bzgluO)]∞ layer with 4,4′-bipy molecules. Complex 4 comprises 3D networks containing small voids occupied by water molecules. The structural difference indicates that the effect of N-donor ancillary ligand is critical in construction of polymeric arrangement. This work will provide a favorable idea for us to construct the higher dimensionality available metal–organic framework. In addition, the solid-state circular dichroism (CD) and the magnetic properties of the complexes were investigated.

Adaptation of guest molecules: A simple system that amplifies the gentle perturbation of host lattices from nickel(II) to cobalt(II)

Two dinuclear complexes [Ni2(μ-bpym)(fum)2(H2O)6]·5H2O (1, bpym=2,2′-bipyrimidine, fum=trans-fumarate) and [Co2(μ-bpym)(fum)2(H2O)6]·2H2O (2) were assembled from MCl2·6H2O (M=Ni, Co), 2,2′-bipyrimidine, and trans-fumaric acid at ambient temperature. In particular, compounds 1 and 2 adopt almost the same molecular structure, but 1 hosts an infinite water chain while 2 traps a discrete tetrameric water cluster. It would arise from the guest water aggregates and would depend on the very slight differences in the coordination chemistry of the Ni(II) and Co(II) centers. The significant influence of metal ions on the resulting structures and the reversible dehydration/rehydration of the complexes further detailed. Photoluminescence spectra of 1 and 2 in the solid state at room temperature were obtained and studied. Magnetic studies showed that both of 1 and 2 afforded a dominant antiferromagnetic coupling between the metal ions.

1D infinite helical water chain encapsulated in a supramolecular complex based on amino acid derivate

ABSTRACTAn oligonuclear complex based on amino acid derivate had been synthesized and structurally characterized, which exhibits a three-dimensional (3D) supramolecular framework constructed from the mono-cobalt units and helical water chains stabilized in this complex. Additionally, the compound was characterized by thermogravimetric analysis (TGA), IR spectroscopy, and elemental analysis.

Syntheses, structures, and properties of transition metal coordination polymers based on a long semirigid tetracarboxylic acid and multidentate N-donor ligands

Six transition metal coordination polymers based on a semirigid tetracarboxylic acid and the multidentate N-donor ligands have been synthesized by the hydrothermal method, namely, {[Co(H2obda) (μ2-H2O) (H2O)2]·2H2O}n (1), {[Co(obda)0.5(bpe) (H2O)2]·3H2O}n (2), {[Zn(H2obda) (H2O)4]·H4obda·6H2O}n (3), {[Zn(bpy) (H2O)4]·H2obda}n (4), {[Ni(bpy) (H2O)4]·H2obda}n (5) and {[Cu(H2obda) (bpy)2]}n (6) (H4obda = 1,4-bis(4-oxy-1,2-benzene dicarboxylic acid)benzene, bpe = 1,2-Bis(4-pyridyl)ethylene), bpy = 4,4′-bipyridine). Compounds 1–6 were structurally characterized by the elemental analyses, infrared spectra, and single crystal X-ray diffractions. Compounds 1–2 exhibit the 2D quadrilateral and polygonal layered grid structures, respectively; a 3D supramolecular structure of 2 has been build via π···π and hydrogen bonds interactions. Compounds 3–6 reveal the 1D zigzag and linear chains structures, respectively; furthermore, 3–5 display the diverse 3D supramolecular structures via hydrogen bonds, respectively. The 1-D infinite water chain in 3 has been found between the lattice water molecules. In addition, the thermogravimetric analyses of 1–6, magnetic property of 1, and photoluminescence of 3–4 have been investigated, respectively.

Implications of hydrogen/halogen-bond in the stabilization of confined water and anion-water clusters by a cationic receptor

Anion complexation of benzene capped flexible tripodal receptor and solid state stabilization of discrete hybrid anion-water or infinite water clusters by various supramolecular interactions are reported here. The crystal structure of the receptor in protonated states shows all the three arms projected in one direction. We structurally demonstrate discrete fluoride-water cluster [F2–H2O]2− and square shaped chloride-water cluster [Cl2–(H2O)2]2− inside the cationic channel of the receptor. Structural analysis also reveals that these clusters are stabilized inside the channel through active participation of N/C/Ow′H⋯Ow, N/C/Ow′H⋯X− (X− = F−, Cl− and I−) H-bonds and electrostatic interactions. Moreover, C–H⋯π and π⋯π types weak intermolecular interactions appear to play crucial role in supramolecular assembly of receptor. Additionally, on treatment with hydroiodic acid (HI) L resulted zwitterionic iodide complex. Crystal structure reveals the presence of S···I halogen bonded dimer, I2···I halogen bond, 1D infinite water chain and neutral iodine molecules. It is comprehensible that ligand basal structure (benzene capped and N-bridge head in two tripodal) play crucial roles in the formation of diverse halide-water cluster. All structures were well examined by different techniques such as NMR, IR, TGA, DSC, PXRD and XRD.

Synthesis, crystal structure and luminescent property of a novel lanthanide coordination polymer containing (H2O)20 clusters

A novel lanthanide coordination polymer, (H2pipz)3[Tb2(pydc)6]·15H2O (1) (where pipz=piperazine and H2pydc=pyridine-2,6-dicarboxylic acid), has been hydrothermally synthesized and characterized by single-crystal X-ray diffraction, infrared spectroscopy, element analysis and thermogravimetric analysis. The most interesting structural feature of 1 consists in the occurrence of one-dimensional infinite water chains made up of novel (H2O)20 clusters. 1 is extended into a three-dimensional supramolecular network structure via an extensive net of hydrogen bonds together with π–π stacking interactions. In addition, 1 was demonstrated to display a green fluorescence emission in the solid state at room temperature.

Infinite 1D water chains present in complexes of Co(II) and Zn(II) with 4,4′,6,6′-tetramethyl-2,2′-bipyrimidine

Two new transition metal complexes [Co(tmbpm)Cl2(H2O)]·2H2O (1) and [Zn(tmbpm)Cl2]·2H2O (2) (where tmbpm = 4,4′,6,6′-tetramethyl-2,2′-bipyrimidine) are synthesized and characterized by IR and single crystal X-ray diffraction. The tmbpm adopts chelating coordination mode in the two mononuclear complexes. Both 1 and 2 form 2D supramolecular structures containing an infinite 1D water chain through hydrogen bonds.

Water clusters in mixed ionic complexes with metal dipicolinate anions

Formations of three different types of hydrogen-bonded water clusters in the interstices of mixed ionic complexes with metal dipicolinate anions are reported. In the complex [Co(phen)2(H2O)2][Zn(dpa)2]⋅7H2O (1) (where phen=1,10-phenanthroline, dpa=dipicolinate), both the cation and anion is hydrophilic in nature, exhibits an unusual 2D infinite cyclic water decamers (H2O)10 stabilized by four identical zinc dipicolinato complex anions. Modulating the cationic unit to a hydrophobic environment by replacing the aqua ligand with 2,2′-bipyridine ligand the water cluster can be modified. The complex [Ni(phen)2⋅bpy][Co(dpa)2]⋅8H2O (2) (where bpy=2,2′-bipyridine) has unprecedented discrete hydrogen bonded hexadecameric (H2O)16 water clusters encapsulated between eight anionic units. A rare wavelike infinite water chain (H2O)n is observed in complex [Co(phen)3][Mn(dpa)2]⋅12H2O (3), in this case the water chain fills the interstitial space created by packing of large hydrophilic anionic units and hydrophobic cationic units. The reported clusters are indefinitely stable in their respective complex at ambient temperature, but the water loss is irreversible when thermally decomposed.

Supramolecular assembled of hexameric water clusters into a 1D chain containing (H2O)6 and [(H2O)4O2] stabilized by hydrogen bonding in a copper complex

BackgroundVarious water clusters including hexamers, heptamers, octamers, decamers and 1D or 2D infinite water chains in a number of organic and inorganic-organic hybrid hosts, have been reported.Results{[Cu(pydc)(amp)].3H2O}n has been hydrothermally synthesized and characterized by elemental analysis and by IR spectroscopy. A wide range of hydrogen bonds (of the O-H...O, N-H...O and N-H...N type) are present in the crystal structure. Hydrogen bond interactions between the co-crystallized water molecules led to formation of six-membered rings with chair conformation.ConclusionIn {[Cu(pydc)(amp)].3H2O}n, there are three uncoordinated water molecules. Thermal methods confirm number of co-crystallized water molecules in polymer. Hydrogen bond interactions between the co-crystallized water molecules led to the formation of a six-membered ring with the chair conformation. These rings are part of a 1D chain containing six-membered O6 rings, which are alternately made from (H2O)6 and [(H2O)4O2] rings. [(H2O)4O2] rings are also in chair conformation.

First-Principles Study of Water Confined in Single-Walled Silicon Carbide Nanotubes

In the present work, water molecules confined inside single-walled silicon carbide nanotubes (SiCNTs) are studied using density functional theory calculations. A set of periodic boundary condition models are established for segments of single-file water chains, infinite single-file water chains, and infinite multifiled water networks encapsulated within the periodic armchair and zigzag SiCNTs with (5,5), (6,6), (8,0), (9,0), and (10,0) chiralities. Two hybrid density functionals with and without dispersion correction, ωB97XD and B3LYP, respectively, are employed in all calculations for structure, interaction energy, and charge analysis. Although the silicon carbide surface is essentially hydrophilic, water molecules within SiCNTs have structures and properties that resemble those in the hydrophobic single-walled carbon nanotube since both are controlled by the geometry confinement. It is necessary to include dispersion corrections to describe the weak interactions between the water molecules and the SiCNT wall which arise mainly from van der Waals interactions and a slight charge transfer from SiCNT to the enclosed water molecules.

Encapsulated two distinct infinite helical water chains in a cyano-bridged copperII–ironII heterometal complex

A bimetallic oligonuclear complex, [trans-{Cu(pmea)2Fe(CN)6]·9H2O (1) (pmea=bis[(2-pyridyl)methyl]-2-(2-pyridyl)ethylamine), had been synthesized and structurally characterized. 1 crystallizes in monoclinic space group P2(1)/c with a=23.924(5)Å, b=10.911(2)Å, c=21.094(4)Å, β=112.46(3)° and Z=4, which exhibits a three dimensional (3D) framework constructed from the water rich 2D sheets. Of particular interest, two kinds of helical water chains coexist in this complex. Comparing the experimental results, it is comprehensible that hosts constructed from the hexacyanometallates plays crucial roles in the formation of the helical structures and water aggregates. Additionally, the compound was characterized by TGA, IR spectroscopy, magnetism and elemental analysis.

Syntheses, structures and properties of two unusual silver–organic coordination networks: 1D→1D tubular intertwinement and existence of an infinite winding water chain

Two unusual metal-organic frameworks {[Ag(2)(Hbtc)(bpy)(2)]·(H(2)O)(2)}(n) (1), {[Ag(3)(btc)(bpy)(3)(H(2)O)]·(H(2)O)(7)}(n) (2) (H(3)btc = 1,2,3-benzenetricarboxylic acid, bpy = 4,4'-bipyridine) have been synthesized and characterized by single crystal X-ray diffraction. Complex 1 features an infinite 1D→1D tubular intertwinement network, while complex 2 exhibits a double ladder structure which contains rare winding water chains. Both infinite 1D→1D tubular chains in complex 1 and double ladder in 2 are mutually interconnected by hydrogen bonding and π···π stacking interactions into three-dimensional (3D) supramolecular networks. In addition, thermogravimetric analysis, powder X-ray diffraction (XRD), and photoluminescent behavior of the complexes have also been investigated.

Self-assembled coordination polymers of V-shaped bis(pyridyl)thiadiazole dependent upon the spacer length and flexibility of aliphatic dicarboxylate ligands

An investigation into 2,5-bis(4-pyridyl)-1,3,4-thiadiazole (bpt) and cupric or cadmium complexes with a large variety of aliphatic α,ω-dicarboxylic acids HOOC-X-COOH (X = (CH2)n, n = 0–4 corresponding to oxalic acid (H2ox), malonic acid (H2mal), succinic acid (H2suc), glutaric acid (H2glu) and adipic acid (H2adi); CHCH, maleic acid (H2male) and fumaric acid (H2fum)) is performed. Ten novel metal–organic architectures, [Cu2(bpt)(ox)2]n·2.92nH2O (1), [Cu(bpt)(mal)(H2O)]n·2nH2O (2), [Cu(bpt)(glu)]n (3), [Cu(bpt)(adi)]n (4), [Cu2(bpt)2(fum)2]n·3nH2O (5), [Cd(bpt)(mal)(H2O)]n (6), [Cd(bpt)(suc)]n (7), [Cd(bpt)(glu)]n·nH2O (8), [Cd2(bpt)2(male)2]n·2nH2O (9), and [Cd(bpt)(fum)(H2O)]n·nH2O (10) were successfully synthesized through varying the organic acid linkers. The molecule 1 is a 3D pillared-layer framework with the open channels encapsulating infinite 1D water chains. Complex 2 shows the contorted 2D layer, which is extended to a 2-fold interpenetrated 3D supramolecular net by antidromic R24(8) hydrogen-bonding pattern. Compound 3 is a grid-like layer motif with the terminal bpt ligands as pendants. The MOFs 4 and 5 present two-fold interpenetrating primitive cubic (α-Po) coordination networks. Interestingly, discrete tetrameric water clusters exist in the micropores of the MOF 5. For the cadmium complex 6, six-coordinated metal centers link malonate and bpt to form interdigitated layers through edge-to-face π–π stacking interactions. Coordination polymer 7 can be considered as six-connected self-penetrated topological 3D network, in which the right- and left-handed helices are alternately arranged into a wavy Cd/succinate layer. Flexible glutarate with cadmium atoms produces a 1D ribbon, and is further linked by bpt ligands to produce the 2D double-layered motif 8. Incorporating with rigid butenedioic acid, the reaction of seven-coordinated cadmium and bpt leads to two distinct 2D (4,4) layered frameworks 9 and 10, with a one-dimensional Cd–O chain observed in the former framework. A systematic structural comparison of these ten complexes indicates that the final polymeric structures could be tuned through the introduction of the different backbone length and flexibility of the aliphatic dicarboxylates. In addition, host–guest chemistry of MOFs 1 and 5, and the luminescent properties of cadmium compounds were discussed.

Metal–organic open frameworks with one-dimension channels assembled with pyridine 2,6-dicarboxylic acid and N-containing auxiliary ligands: Syntheses, crystal structures, and physical characterization

Four new complexes, {[Mn(imH) 2(pdc)]·H 2O} n ( 1), [Zn 2(pdc) 2(H 2O) 5]·2H 2O ( 2), [Zn(imH) 2(pdc)]·H 2O ( 3), {[Zn 2(pdc) 2(bpy)(H 2O) 2]·5H 2O} n ( 4) [imH = imidazole pdc = pyridine 2,6-dicarboxylate, bpy = 4,4′-bipyridine] have been synthesized under hydrothermal conditions and structurally characterized by elemental analysis, IR, PXRD, single-crystal X-ray diffraction and thermogravimetric analyses. All the four complexes display a three-dimensional (3D) open framework with one-dimensional (1D) channels that are filled with lattice water molecules. Particularly, in 4, the lattice water molecules form an infinite water chain. Both 1 and 4 consist of 1D polymeric chains. While 2 contains a dinuclear Zn(II) unit, and 3 is a mononuclear complex. Further, the result of thermal analysis of 1 and 2 shows the robustness of the overall supramolecular three-dimensional architecture. Complexes 1, 3, and 4 exhibit strong fluorescent emissions in the solid state at room temperature and could be significant in the field of photoactive materials.

Hydrothermal synthesis and characterization of two 2-D lanthanide-2,2′-bipyridine-3,3′-dicarboxylate coordination polymers based on zigzag chains

Two lanthanide coordination polymers, {[La 2(bpdc) 3(H 2O) 4]·(H 2O) 4} n ( 1) and {[Sm 2(bpdc) 3(H 2O) 2]·(H 2O) 5} n ( 2) (H 2bpdc = 2,2′-bipyridine-3,3′-dicarboxylic acid) have been obtained by hydrothermal synthesis. Single-crystal X-ray diffraction shows that 1 and 2 are two-dimensional network structures based on the zigzag chains which are linked by bpdc ligands, forming the first examples of binary lanthanide polymers with bpdc. It is unprecedented that the adjacent zigzag chains are symmetrical in mirror images with the arraying form of ⋯ ABAB ⋯ . In 1 and 2, lanthanide ion are all nine-coordinate and bpdc ligands exhibit different kinds of coordination modes. The 1-D infinite water chain in 1 and pentameric water ring in 2 have been found between lattice water molecules. Thermo-gravimetric analyses of 1 and 2 display considerable thermal stability. Photoluminescent properties of 1 and 2 are discussed.

A new binuclear potassium (І) complex with a novel 1D infinite water chain containing (H2O)12 clusters

Abstract A novel 1D infinite water chain made of (H2O)12 clusters containing two different chair water hexamers is found in the binuclear coordination compound, [K2(L)2(phen)4]·6H2O (1) (where L = 2,2′-azanediyldibenzoic dianion, phen = 1,10′-phenanthroline), which has been synthesized and structurally characterized by single-crystal X-ray diffraction. The fluorescence spectrum and thermogravimetric analysis (TGA) of the title complex 1 have been also discussed.

A novel three-dimensional framework constructed by 2-[(1H-imidazol-1-yl)methyl]-1H-benzimidazole and infinite chains of hydrogen-bonded water molecules

A novel three-dimensional framework of 2-[(1H-imidazol-1-yl)methyl]-1H-benzimidazole dihydrate, C(11)H(10)N(4).2H(2)O or L.2H(2)O, (I), in which L acts as both hydrogen-bond acceptor and donor in the supramolecular construction with water, has been obtained by self-assembly reaction of L with H(2)O. The two independent water molecules are hydrogen bonded alternately with each other to form a one-dimensional infinite zigzag water chain. These water chains are linked by the benzimidazole molecules into a three-dimensional framework, in which each organic molecule is hydrogen bonded by three water molecules. This study shows that the diversity of hydrogen-bonded patterns plays a crucial role in the formation of the three-dimensional framework. More significantly, as water molecules are important in contributing to the conformation, stability, function and dynamics of biomacromolecules, the infinite chains of hydrogen-bonded water molecules seen in (I) may be a useful model for water in other chemical and biological processes.

Structures of an infinite helical water chain and discrete lattice water in metal–organic framework structures

Two supramolecular complexes Ni[(Py)2C(OH)2]2·(CH3COO)2·4H2O 1 and Co[(Py)2C(OH)2]2·(CH3COO)2·2H2O 2 have been synthesized under hydrothermal conditions and structurally characterized by elemental analysis, IR spectra, and X-ray single-crystal diffraction. The X-ray diffraction analysis indicates that the center metal (Ni2+ and Co2+) ions having the same coordination environments are chelated by two pyridyl N atoms and a hydroxyl O atom of the gem-diol ligand in an octahedral geometry. In 1, the lattice water molecules form infinite single helical chains, while in 2, two lattice water molecules are discrete. In their crystal structures, intermolecular O–H···O and C–H···O hydrogen bonds form an extensive three-dimensional network, which consolidates the crystal packing.