Infinite Water Chain Research Articles

Self-Assembled Copper(II) Coordination Polymers Derived from Aminopolyalcohols and Benzenepolycarboxylates: Structural and Magnetic Properties

The new copper(II) or copper(II)/sodium(I) 1D coordination polymers [Cu2(Hmdea)2(mu-H2O)(mu2-tpa)]n.2nH2O (1), [Cu2(H2tipa)2(mu2-ipa)]n.4nH2O (2), [Cu2(H2tea)2Na(H2O)2(mu2-tma)]n.6nH2O (3), [Cu2(H2tea)2(mu2-ipa)]n.nH2O (4a), and [Cu2(H2tea)2{mu3-Na(H2O)3}(mu3-ipa)]n(NO3)n.0.5nH2O (4b) have been prepared in aqueous medium by self-assembly from copper(II) nitrate, aminopolyalcohols [methyldiethanolamine (H2mdea), triisopropanolamine (H3tipa), and triethanolamine (H3tea)] as main chelating ligands and benzenepolycarboxylic acids [terephthalic (H2tpa), isophthalic (H2ipa), and trimesic (H3tma) acid] as spacers. They have been characterized by IR spectroscopy, elemental and single-crystal X-ray diffraction analyses, the latter indicating the formation of unusual multinuclear metal cores interconnected by various benzenepolycarboxylate spacers, leading to distinct wavelike, zigzag, or linear 1D polymeric metal-organic chains. These are further extended to 2D or 3D hydrogen-bonded supramolecular networks via extensive interactions with the intercalated crystallization water molecules. The latter are associated, also with aqua ligands, by hydrogen bonds resulting in acyclic (H2O)3 clusters in 1, (H2O)8 clusters in 2, infinite 1D water chains in 3, and disordered water-nitrate associates in 4b, all playing a key role in the structure stabilization and its extension to further dimensions. Variable-temperature magnetic susceptibility measurements have shown that 1-4 exhibit a moderately strong ferromagnetic coupling through the alkoxo bridge. The small Cu-O-Cu bridging angle and the large out-of-plane displacement of the carbon atom of the alkoxo group accounts for this behavior. The magnetic data have been analyzed by means of a dinuclear and a 1D chain model, and the magnetic parameters have been determined. The magnetic exchange coupling in 3, to our knowledge, is the highest found in alkoxo-bridged copper(II) complexes.

Formation of a 1D water chain into the channel of a unique 3D hydrogen-bound coordination polymer {[Cd(μ-Cl)(4-pya)(H 2O)] 2 · 4H 2O} ∞ (4-pya = trans-4-pyridylacrylate)

A novel Cd(II)/4-pya coordination polymer {[Cd(μ-Cl)(4-pya)(H 2O)] 2 · 4H 2O} ∞ ( 1) (4-pya = trans-4-pyridylacrylate) was synthesized and structurally characterized. Single-crystal X-ray diffraction revealed that 1 consists of a 2D (4, 4) network constructed from the 4-pya bridging ligand and the dimeric [Cd(μ-Cl)] 2 cores, in which each six-coordinated Cd(II) ion adopts an octahedral coordination geometry. Each 2D layer is further stacked along the a axis through hydrogen bonding interactions to afford a 3D hydrogen-bound network. An infinite water chain is generated via hydrogen bonds into each resulting 1D channel. The luminescent properties of 1 in the solid state were investigated.

Hydrothermal synthesis and structural characterization of three new transition-metal coordination polymers with 2-carboxycinnamic acid

Three new coordination polymers, [Zn 2(CCA) 2(bpy)] n·0.5 nbpy ( 1), [Zn(CCA)(bpe)(H 2O)] n·0.5 nH 2O ( 2) and [Mn(CCA)(bpe)] n·2 nH 2O ( 3) (H 2CCA = 2-carboxycinnamic acid; bpy = 4,4′-bipyridine; bpe = 1,2-bis(4-pyridyl)ethane) have been synthesized by the hydrothermal reactions and characterized by single crystal X-ray diffraction, elemental analysis and IR spectrum. Although both complexes 1 and 2 possess 3D metal-organic frameworks, CCA ligands adopt different coordination modes in them. This can be attributed to the introduction of different auxiliary ligands bpy and bpe. In complex 3, CCA ligands link Mn(II) ions into 1D infinite double-strand helical chains and these chains are bridged by bpe to 2D layers. There are hydrogen bonds among the free water molecules, leading to the formation of 1D infinite water chains, which play an important role in the construction of the 3D microporous network. The fluorescent properties of complexes 1 and 2 have also been investigated.

Unusual hexamers and infinite water chains trapped in the complexes of 2-(4-pyridyl)benzimidazole

Unusual hexamers and water chains have been observed in the complexes of (HPyBIm) + (Hterephate) − (PyBIm) · 4H 2O ( 1) and [Ag 2(PyBIm) 2(μ 2-SO 4)] · 4H 2O ( 2), respectively (PyBIm = 2-(4-pyridyl)benzimidazole). In 1, a chair-shaped hexamer (not water hexamer) formed by the water molecules and carboxylate groups as well as one-dimensional water chain are being observed. While in 2, a water hexamer-shaped as parallelogram is obtained; more interestingly, the parallelogram-shaped water hexamers are further aggregated into tape like infinite water chain via hydrogen-bonding interactions.

A novel self-assembled chain of water molecules in a metal-organic framework of Cu(II) with isophthalate

A novel coordination polymer, {[Cu(ip)(Him)2(H2O)]·3H2O} (1), (ip=isophthalate, Him=imidazole) was prepared under hydrothermal conditions and its structure is determined by single-crystal X-ray diffraction. X-ray structural analysis reveals that 1D zigzag metal-organic framework was connected to form a 3D metal-organic framework by a novel infinite 1D water chain constructed by five- and six-membered rings through edge-sharing. These water chains behave as glue to stabilize the 3D network. Upon removal of the water molecules by heating, the 3D structure breaks down. Thermogravimetric analysis, infrared, X-ray powder diffraction studies, elemental analysis and magnetic analysis were performed to characterize this compound.

Crystallographic and Theoretical Evidence of Acetonitrile−π Interactions with the Electron-Deficient 1,3,5-Triazine Ring

Reaction of zinc(II) chloride with the ligand N,N‘-{2,4-(di-2-pyridylamino)-1,3,5-triazin-6-yl}-1,4,10,13-tetraoxa-7,16-diazacyclooctadecane (oxodendtriz) in acetonitrile/methanol results in the formation the tetranuclear complex [Zn4(oxodendtriz)Cl8](CH3CN)2(H2O)1.5. Notably, its crystal structure reveals unique π-interactions with the first experimental evidence of electron-rich/electron-poor molecule pairing, which is corroborated by computational studies. In addition, infinite helical water chains with both right- and left-handed configurations are present in the crystal lattice.

Structural Impact of Infinite Water Chains on the Self-Assembly of an Inorganic−Metal−Organic Architecture

The structure of {p-C6H4[CH2OCH2C(pz)3]2[Ru(p-cymene)]2}Cl4·14H2O (pz = pyrazolyl ring) contains a one-dimensional water chain associated into an inorganic (carbon-free) layer with chloride anions by hydrogen bonds. This layer acts as a “host” supporting the non-self-assembled metal−organic “guests”.

Infinite Water Chains Trapped in an Organic Framework Constructed from Melamine with 1,5-Naphthalenedisulfonic Acid via Hydrogen Bonds

Cocrystallizations of melamine (MA) with 1,5-naphthalenedisulfonic acid (H2NDA) from water in different molar ratios (2:1, 4:1, and 8:1) offer [(HMA+)2(NDA2-)]·4H2O (1), [(HMA+)2(MA)2(NDA2-)]·8H2O (2), and [(HMA+)2(MA)2(NDA2-)]·10H2O (3), respectively. Among them, sulfonic protons are transferred to the triazine nitrogen atoms of MA, furnishing hydrogen-bonded anionic [(NDA2-)·H2O]∞ chains. In 1, the adjacent HMA+ cations form cationic (HMA+)∞ ribbons via pairs of N−H···N hydrogen bonds ( (8) synthon), and the ribbons connect to each other through NDA2- anions as well as lattice water molecules via hydrogen bonds and C−H···π, π···π, and electrostatic interactions to form a 3D structure. In 2 and 3, only half of the MA molecules are protonated, resulting in cationic (MA·HMA+)∞ ribbons via N−H···N hydrogen bonds. In 2, hydrophilic channels (size 3.9 × 6.1 A2) enclosed by the NDA2- anions and (MA·HMA+) cations are found to host a pair of zigzag water chains, which are interlinked through sulfonate oxygen ato...

An Infinite Water Chain Passes through an Array of Zn(II) Metallocycles Built with a Podand Bearing Terminal Carboxylates

A podand bearing three carboxylic acid groups was synthesized by condensation of tris(2-chloroethyl)amine with 4-hydroxyethylbenzoate followed by hydrolysis of the ester group. An aqueous solution of Zn(NO3)2 x 6H2O reacts with the tetraethylammonium salt of the podand at room temperature, to form a porous coordination polymeric structure with infinite interlinked chains of Zn(II) metallocycles. An infinite water chain passes through the metallocycles like a thread. The compound was characterized by X-ray crystallography, X-ray powder diffraction, TGA, IR spectroscopy, and elemental analysis.

Structures and solid-state dynamics of one-dimensional water chains stabilized by imidazole channels.

Proton wires: One-dimensional water chains play an important role in proton permeation through transmembrane proteins. The X-ray crystal structures as well as solid-state 2H and 17O NMR and calorimetry studies of two imidazole hydrates that stabilize infinite one-dimensional water chains are reported (see picture; N blue, O red, H white). The 2H NMR spectroscopic studies suggest that water molecules in both compounds undergo different reorientational dynamics.

Non-linear optical properties of quasi-one-dimensional periodic systems: consistent theoretical treatment within the crystal orbital method

The concepts of the interaction of a homogeneous electric field with a periodic quasi-one-dimensional system are discussed. The translational periodicity in the presence of the electric field is demostrated using a transformation of the Hamilton operator. The periodic perturbation Hamiltonian is introduced into the ab initio Hartree–Fock crystal orbital method and the generalized hermitian eigenvalue problem is solved with a self-consistent iteration procedure. Calculations of the static polarizability of an infinite water chain as a model and of polyyne are performed and compared with results reported in the literature.

Cooperative effects in hydrogen bonding: Fourth-order many-body perturbation theory studies of water oligomers and of an infinite water chain as a model for ice

As a step toward the first principles quantum mechanical modeling of the structural and electronic properties of ice, hydrogen-bonded periodic infinite chains of water molecules have been investigated by the ab initio crystal orbital method at the Hartree–Fock (HF) level and by including electron correlation up to the complete fourth order of Mo/ller–Plesset perturbation theory (MP4). The Bloch functions of the crystal have been expanded in a series of high quality atomic orbital basis sets complemented by extended sets of polarization functions, up to TZ(3d2f,3p2d). Basis set superposition errors have been (partly) eliminated by the counterpoise method and the infinite lattice sums have been computed using the multipole expansion technique. The systematically increasing size of the basis sets has allowed the extrapolation of structural and electronic indices of this ice model to the limit of an infinite atomic basis at both the HF and various correlated levels, respectively. For each theoretical model, detailed comparisons have been made with the corresponding physical properties of water monomers, dimers, and some larger linear oligomers. The results convincingly prove that hydrogen bonding in ice is a highly cooperative phenomenon, both from the structural and energetic points of view. The cohesive energy per hydrogen bond of the crystal is −5.30 kcal/mol at the HF level (with RHFO,O=2.88 Å) as compared with the dimer value of −3.60 kcal/mol (at the optimized distance of 3.03 Å). At the MP2 level of theory, the crystalline binding energy decreases to −6.60 kcal/mol and the lattice contracts to RMP2O,O=2.73 Å (compared with −4.50 kcal/mol at 2.88 Å for the dimer). The correlation corrections at third and fourth order slightly expand the crystal lattice (to RMP4O,O=2.75 Å) and reduce the cohesion by 0.15 kcal/mol. A decomposition of the intermolecular interactions according to different terms of MP4 theory suggests that the cohesive energy of ice results from a delicate balance between different repulsive and attractive terms in third and fourth order, which exhibit different long-range behaviors. The detailed study of the role of high-energy virtual energy bands in computing electron correlation effects in ice provides further insight into the important role that basis set flexibility plays in such investigations. The resulting cohesive energy of −6.83 kcal/mol at the MP4 level is in reasonable agreement with the experimental energy per hydrogen bond in ice I, −6.7 kcal/mol.

One-dimensional water chain in the zeolite bikitaite: Neutron diffraction study at 13 and 295 K

The crystal structure of the natural zeolite bikitaite, Li 2Al 2Si 4O 12·2H 2O from Bikita, Zimbabwe, has been determined by neutron diffraction at 295 and 13 K. Space group P1, Z = 1, a = 8.6071(9), b = 4.9540(5), c = 7.5972(7) Å, α = 89.900(7), β = 114.437(8), γ = 89.988(8)°, V = 294.9(1) Å 3 at 295 K, and a = 8.5971(8), b = 4.9395(4), c = 7.6121(7) Å, α = 89.850(7), β = 114.520(7), γ = 90.004(7)°, V = 294.10(4) Å 3 at 13 K. λ = 1.0505(1) Å, μ = 0.650 cm −1, D x = 2.28 g/cm 3. Final R( F) = 0.027 and 0.026 for 1845 and 2083 unique reflections at 295 and 13 K, respectively. Refined values of Si Al site occupancies show a high degree of ordering, which results in a triclinic distortion from the monoclinic symmetry reported by X-ray studies. The H 2O molecules are hydrogen bonded only to each other, H···O = 1.949(3) and 1.955(3) Å, and with H···O (framework) distances in the range 2.544(4)-2.946(4) Å. The infinite water chains, parallel to b, are linked to the zeolite framework by Li +···O w coordination only. The Li + ions are each tetrahedrally coordinated by one water and three SiOAl oxygens. The Li coordination causes a strong decrease in the SiOAl angles. The significant structural changes when going from 295 to 13 K are stronger hydrogen bonding and a general decrease in the SiO Si Al angles.