Formation of an infinite 2D-layered water of (H2O)45 cluster in a cryptand-water supramolecular complex: a template effect

Structural aspects governing the formation of the water layer in the octaaminocryptand L were examined. Crystallographic results reveal an unprecedented, infinite two-dimensional (2D) layer of water molecules by interconnection of (H2O)45 clusters under confined conditions. This unique 2D layer is basically a template effect of L where the N4 donor sets facilitate the formation of the crown shape water at both ends which, on propagation, generates an infinite through-channel down the c-axis. Thermal analysis, powder X-ray diffraction, and IR studies carried out on L.(H2O)15, 1, support the crystallographic results.     

Communication: determination of the bond dissociation energy (D0) of the water dimer, (H2O)2, by velocity map imaging

The bond dissociation energy (D(0)) of the water dimer is determined by using state-to-state vibrational predissociation measurements following excitation of the bound OH stretch fundamental of the donor unit of the dimer. Velocity map imaging and resonance-enhanced multiphoton ionization (REMPI) are used to determine pair-correlated product velocity and translational energy distributions. H(2)O fragments are detected in the ground vibrational (000) and the first excited bending (010) states by 2 + 1 REMPI via the C? (1)B(1) (000) ← X? (1)A(1) (000 and 010) transitions. The fragments' velocity and center-of-mass translational energy distributions are determined from images of selected rovibrational levels of H(2)O. An accurate value for D(0) is obtained by fitting both the structure in the images and the maximum velocity of the fragments. This value, D(0) = 1105 ± 10 cm(-1) (13.2 ± 0.12 kJ/mol), is in excellent agreement with the recent theoretical value of D(0) = 1103 ± 4 cm(-1) (13.2 ± 0.05 kJ∕mol) suggested as a benchmark by Shank et al. [J. Chem. Phys. 130, 144314 (2009)].     

Characterization of supramolecular (H2O)18 water morphology and water-methanol (H2O)15(CH3OH)3 clusters in a novel phosphorus functionalized trimeric amino acid host

Phosphorus functionalized trimeric alanine compounds (l)- and (d)-P(CH(2)NHCH(CH(3))COOH)(3) 2 are prepared in 90% yields by the Mannich reaction of Tris(hydroxymethyl)phosphine 1 with (l)- or (d)- Alanine in aqueous media. The hydration properties of (l)-2 and (d)-2 in water and water-methanol mixtures are described. The crystal structure analysis of (l)-2.4H(2)O, reveals that the alanine molecules pack to form two-dimensional bilayers running parallel to (001). The layered structural motif depicts two closely packed monolayers of 2 each oriented with its phosphorus atoms projected at the center of the bilayer and adjacent monolayers are held together by hydrogen bonds between amine and carboxylate groups. The water bilayers are juxtaposed with the H-bonded alanine trimers leading to 18-membered (H(2)O)(18) water rings. Exposure of aqueous solution of (l)-2 and (d)-2 to methanol vapors resulted in closely packed (l)-2 and (d)-2 solvated with mixed water-methanol (H(2)O)(15)(CH(3)OH)(3) clusters. The O-O distances in the mixed methanol-water clusters of (l)-2.3H(2)O.CH(3)OH and (d)-2.3H(2)O.CH(3)OH (O-O(average) = 2.857 A) are nearly identical to the O-O distance observed in the supramolecular (H(2)O)(18) water structure (O-O(average) = 2.859 A) implying the retention of the hydrogen bonded structure in water despite the accommodation of hydrophobic methanol groups within the supramolecular (H(2)O)(15)(CH(3)OH)(3) framework. The O-O distances in (l)-2.3H(2)O.CH(3)OH and (d)-2.3H(2)O.CH(3)OH and in (H(2)O)(18) are very close to the O-O distance reported for liquid water (2.85 A).     

A large protonated water cluster H+(H2O)27 in a 3D metal-organic framework

A large protonated water cluster, H+(H2O)27, has been trapped and stabilized within the well-modulated cavity of a 3D metal-organic framework formed by cobalt(II) and 4,4'-bipyridine-N,N'-dioxide with a globular Keggin structure [PW12O4]3- anion as template. The structurally characterized protonated water cluster might comprise a (H2O)26 shell with Oh symmetry and a monowater core within the center which is suggested to be a hydronium ion with the Eigen model.     

Lowest-energy structures of water clusters (H2O)11 and (H2O)13

We employed a four-step searching/screening approach to determine best candidates for the global minima of (H2O)11 and (H2O)13. This approach can be useful when there exist a large number of low-lying and near-isoenergetic isomers, many of which have the same oxygen-skeleton structure. On the two new candidates for the global minimum of (H2O)11, one isomer can be viewed as placing the 11th molecule onto the side of the global minimum of (H2O)10 and the other can be viewed as removing the 12th molecule from the middle layer of the global minimum of (H2O)12. The three leading lowest-energy clusters of (H2O)13 can all be built starting from the global minimum of (H2O)12, with the difference being in the location of the 13th water molecule.     

超分子化合物[CO(bppdca)_2(HL)_2(H_2O)_2]·2H_2O]的晶体结构和性质

以N,N′-二(3-吡啶基)-吡啶-3,5-二甲酰胺(bppdca)和1,4-环己烷二羧酸(H2L)为混合配体,利用水热合成方法获得了一个三维的超分子化合物[CO(bppdca)2(HL)2(H2O)2]·2H2O],并通过元素分析、IR和单晶X射线衍射技术确定了该化合物晶体结构.结构分析表明该化合物属单斜晶系,P21/n空间群,晶胞参数a=0.820 65(6)nm,b=1.259 76(9)nm,c=2.479 11(18)nm,β=98.061 0(10)°,Z=2,V=2.537 6(3)nm3,Mr=1 111.98,Dc=1.455g/cm3,F(000)=116 2,μ=0.421mm-1,S=1.018,R=0.041 7,wR=0.102 3.晶体结构分析表明,配合物中的CoⅡ与2个bppdca配体、2个HL阴离子以及2个配位水分子形成单金属配合物.相邻的配合物通过氢键作用拓展成三维超分子框架.另外,也研究了该化合物的热稳定性、荧光性质以及光催化性质.     

An unprecedented uranyl phosphate framework in the structure of [(UO2)3(PO4)O(OH)(H2O)2](H2O)

The new uranyl phosphate [(UO2)3(PO4)O(OH)(H2O)2](H2O) (1) with an unprecedented framework structure has been synthesized at 150 and 185 degrees C. The structure (tetragonal, P4(2)/mbc, a = 14.015(1) A, c = 13.083(2) A, V = 2575.6(4) A(3), Z = 8) contains uranyl phosphate chains composed of uranyl pentagonal and hexagonal bipyramids and phosphate tetrahedra linked by sharing of polyhedral edges. The uranyl phosphate chains are aligned both along [100] and [010] and are linked into a novel framework structure involving channels along [001]. Topologically identical chains occur linked into sheets in more than a dozen uranyl phosphate minerals, but these chains have never been observed in opposing orientations and linked into a framework as in 1.     

Water-soluble supramolecular porphyrin dimer: self-organization of mono(imidazolyl)-substituted Zn porphyrin to a special-pair type dimer in water

Tris(4-carboxylphenyl)-mono(N-methylimidazolyl)-substituted Zn porphyrin was synthesized as a precursor for a water-soluble supramolecular porphyrin dimer. The dimer formation was performed in a NaHCO₃ aq solution (pH 8.4) and phosphate buffer solutions (pH 7.4-9.0). The split Soret bands of Zn porphyrin observed in the absorption spectra clearly showed self-organization to a special-pair type slipped cofacial dimer via metal coordination of imidazole even in water.     

Na6(H2O)20(V10O28)·4H2O,a novel polyvanadate(V) with a three‐dimensional framework

The novel title polyvanadate(V), poly[[octa‐μ‐aqua‐dodecaaqua‐μ₄‐octacosaoxidodecavanadato‐hexasodium] tetrahydrate], [Na₆(H₂O)₂₀(V₁₀O₂₈)·4H₂O]_n, contains [V₁₀O₂₈]⁶⁻ anions which lie about inversion centres and have approximate 2/m symmetry and which are linked to [Na₃(H₂O)₁₀]³⁺ cations through two terminal and two μ₂‐bridging O atoms. The structure contains three inequivalent Na⁺ cations, two of which form [Na₂(H₂O)₈]_n chains, which are linked via NaO₆ octahedra involving the third Na⁺ ion, thus forming a three‐dimensional framework.     

GeTe2O6, a germanium tellurate(IV) with an open framework

The structure of an already evidenced but still uncharacterized GeTe₂O₆ phase consists of isolated GeO₆ octahedra connected via isolated TeO₃ units. The germanium cations occupy a site with symmetry. The Te and O atoms are in general positions of the P2₁/n space group. This structure corresponds to a new type of tetravalent tellurate and is different from other AB₂X₆ structures in which the B cation presents a stereochemically active electronic lone pair. It derives from the pseudo‐hexagonal MI₂O₆ (M = Mg, Mn, Co and Fe) type by a strong monoclinic distortion caused by the much smaller size of Ge⁴⁺ compared with the divalent M cations.     

Polyoxometalate (W/Mo) compounds connected via lanthanide cations with a three-dimensional framework, H2{[K(H2O)2]2[Ln(H2O)5]2(H2M12O42)}.nH2O: synthesis, structures, and magnetic properties

A series of 10 novel polyoxometalate (W/Mo) compounds connected via a trivalent lanthanide cation bridge, H2{[K(H2O)2]2[Ln(H2O)5]2(H2M12O42)}.n(H2O) (Ln = La, Sm, Eu, Gd, Tb, Dy, Ho, Er, Yb, Lu; M = W or W/Mo) (1-10), were designed and synthesized on the basis of the abduction of Al3+ in aqueous solution. X-ray diffraction analyses reveal that the structures of complexes 1-10 are three-dimensional frameworks assembled from the arrangement of H2M12O42(10-) (named paradodecmetalate-B) and Ln(H2O)53+ with two planes, which are constructed via the unification of H2M12O42(10-) and Ln(H2O)53+, along the [100] and [001] directions. Magnetic measurements reveal the paramagnetic properties and a strong ferromagnetic coupling between the two nearest-neighboring lanthanide cations, Ln3+ (Ln = Dy, Er), within the circle for compounds 2 and 4-9.     

V(III)(H2O)]3O(O2CC6H4CO2)3.(Cl, 9H2O) (MIL-59): a rare example of vanadocarboxylate with a magnetically frustrated three-dimensional hybrid framework

[V(III)(H2O)]3O(O2CC6H4CO2)3.(Cl, 9H2O) (denoted MIL-59) presents a three-dimensional framework built up from octahedral vanadium trimers joined via the isophthalate anionic linkers to delimit cages where water molecules and chlorine anions are occluded; the frustrated magnetic behaviour of MIL-59 is discussed.     

The first 3-D ferrimagnetic nickel fumarate with an open framework: [Ni3(OH)2(O2C-C2H2-CO2)(H2O)4].2H2O

A three-dimensional nickel fumarate has been isolated by hydrothermal reaction and its structure solved from powder X-ray diffraction; its organisation reveals an unusual topology not previously seen in nickel chemistry and provided a scarce ferrimagnetic behaviour below 20 K.     

(Th2F5)(NC7H5O4)2(H2O)][NO3]: an actinide-organic open framework

We believe [(Th2F5)(NC7H5O4)2(H2O)][NO3] is the first three-dimensionally connected, actinide-organic framework solid. The structure is composed of thorium oxyfluoride chains, each of which connected to pyridinedicarboxylate groups to give a 3D cross-linked network with cavities containing nitrate anions.     

Inorganic supramolecular host architectures: [(M@18c6)2][TlI4].2H2O, M=0.5 Tl, (NH4,NH3), (H3O,H2O)

The compounds [(M@18c6)2][TlI4].2H2O, M=Tl, (NH4,NH3), (H3O,H2O) (cubic, Fd; a=1481.00 pm, for M=0.5 Tl, a=1304.65 pm for M=(NH4,NH3), a=1313.67 pm for M=(H3O,H2O)) can be obtained from solution in the presence of traces of transition metal halides (like copper and mercury halides). Apparently the transition metal cations work as a template in the form of tetrahedral [MX4] units during the synthesis of the supramolecular host architecture. That the compounds are versatile host lattices for tetrahedrally coordinated transition metal units becomes obvious by the large group of known host-guest complex compounds, [(MIIX4)(MI@18c6)4][TlX4]2.nH2O (MII=Cu, Co, Zn, Mn; MI=NH4+, Rb, Tl; X=Cl, Br).     

Potential energy surface of the (H2)2 dimer: an MP2 study

Fifteen structures of the (H₂)₂ dimer have been investigated at the MP2/[4s3p] level. The SCF and MP2 (2nd order Møller-Plesser treatment) interaction energies have been corrected for the basis set superposition error. Only the T-shaped structure has been established as a minimum on the potential energy surface. Two equivalent T-shaped structures are connected by a saddle point with a rhomboid structure.Dedicated to Professor J. Koutecký on the occasion of his 65th birthday     

Imaging H2O photofragments in the predissociation of the HCl-H2O hydrogen-bonded dimer

The state-to-state vibrational predissociation (VP) dynamics of the hydrogen-bonded HCl-H(2)O dimer was studied following excitation of the dimer's HCl stretch by detecting the H(2)O fragment. Velocity map imaging (VMI) and resonance-enhanced multiphoton ionization (REMPI) were used to determine pair-correlated product energy distributions. Following vibrational excitation of the HCl stretch of the dimer, H(2)O fragments were detected by 2 + 1 REMPI via the C (1)B(1) (000) ← X (1)A(1) (000) transition. REMPI spectra clearly show H(2)O from dissociation produced in the ground vibrational state. The fragments' center-of-mass (c.m.) translational energy distributions were determined from images of selected rotational states of H(2)O and were converted to rotational state distributions of the HCl cofragment. The distributions were consistent with the previously measured dissociation energy of D(0) = 1334 ± 10 cm(-1) and show a clear preference for rotational levels in the HCl fragment that minimize translational energy release. The usefulness of 2 + 1 REMPI detection of water fragments is discussed.     

The novel monomeric bis(orotate-N,O) supramolecular complex of manganese(II): Synthesis,spectrothermal properties and crystal structures of (enH2)[Mn(HOr)2(H2O)2]·2.5H2O

A novel supramolecular complex containing zigzag chain of ethylenediammonium trans-diaquabis(orotato)manganate(II) hydrate (1) has been synthesized and characterized by using IR spectroscopy, thermal analysis (TG, DTG and DTA) and X-ray crystallographic studies. The complex reveals that the Mn(II) atom exhibits a distorted octahedral geometry coordinated by nitrogen and oxygen atoms of two orotate ligands, oxygen atoms of the two aqua ligands. The supramolecular network is constructed by one dimensional novel cyclic dimer zigzag chain, which was further linked by strong hydrogen bonds formed between N and O atoms.