Coordination polymeric solid, {[Ag 2 (bpp) 2 (H 2 O) 2 ](chd)·9H 2 O} n (1) (bpp = 1,3-bis(4-pyridyl) propane, H 2 chd = 1,4-cyclo-hexanedicarboxylic acid), has been obtained by the solution phase ultrasonic synthesis techniques. The structure established through X-ray structural analysis shows that the compound traps an interesting 1D water tape built by the alternating "three-pointed star" cage-like pentameric and D 2h tetrameric clusters (C2/c, Z = 4; a = 30.37(2) , b = 9.271(5) , and c = 18.89(1) ; β = 128.47°; V = 4164(4) 3 ). The novelty of the present complex is the rarely crystallographic example of the cage-shaped water pentamer, which is usually ascribed to a less-stable species. A first-principle density functional theory (DFT) calculation demonstrates that the interconnectivity between cage-like pentamers and D 2h tetramers is beneficial for contribution to the structural stabilization of these less-stable water cluster species.
An octameric water moiety which consists of a chairlike water hexamer and two pendent water molecules in the 1,4-diaxial positions and shows a similar structure to the hydrocarbon(1r,4r)-1,4-dimethylcyclohexane,is unambiguously trapped in a2D Cu(Ⅱ) mixed-ligand coordination polymer,{[Cu2(bpp)2(H2O)2(bpda)2 ].6H2O} n(1)(bpp = 1,3-bis(4-pyridyl)propane and H2 bpda =2,2'-biphenyldicarboxylic acid).The water octamer can be extended into a hybrid carboxylate-water decamer when carboxylic oxygen atoms from bpda2 are involved.Interestingly,the present hybrid decamer bears a similar structural topology to a butterfly(H2O) 10 cluster.The reversible dehydration/hydration of 1 is determined by X-ray powder diffraction studies.
LUO GengGengWU DongLiangLIU LiLI DongXuZHAO QingHuaXIAO ZiJingDAI JingCao
Ce/Sm ions are covalently grafted to a Keggin polyoxomolybdate cluster[PMo12O40]3-to yield interesting fluorescent-photodarkening molecular systems.Their photoresponce processes are observed to be activated via energy transfer from luminescent fragments to photocoloration components.
A discrete centrosymmetric(H2O)20(CH3OH)4 binary cluster was confined in the cavity of a metal-ligand hybrid [Ag4(bpda)2(bpp)4·14H2O·2CH3OH] n(1)(where bpp = 1,3-bis(4-pyridyl)propane and H 2 bpda = 2,2'-biphenyldicarboxylic acid).The novel mixed water-methanol cluster consists of one grail-shaped hexadecameric cluster,four dangling water and four hanging methanol molecules.The(H 2 O) 16 cluster is composed of two pairs of edge-sharing(H2O) 5 rings attached to one(H2O) 4 core with twenty hydrogen bonds.Alternatively,the(H2O) 16 cluster is structurally similar to a complicated hydrocarbon generated by undergoing [2+2] cycloaddition of 1,2,3,4,5,6-hexahydropentalene,which reveals the resemblance between water clusters and organic compounds.
LUO GengGengHE WeiJunLIU LiWU ShengHuLI DongXuXIAO ZiJingDAI JingCao
The new complex, [Co2(adc)2(py)4(H2O)}n 1 (adc = 1,3-adamantanedicarboxylate, py = pyridine), has been hydrothermally synthesized as polymeric solid, and characterized by X-ray diffraction, elemental analysis, IR spectra and thermogravimetric analysis. Complex 1 crystallizes in monoclinic, space group C2/c with a = 18.932(4), b = 19.779(4), c = 12.352(3) , β = 112.03(3)o, V = 4288(2) 3, Z = 4, GOF = 0.998, R = 0.0518 and wR = 0.1074. X-ray single-crystal analysis reveals that 1 presents a 3D simple parallel rod-like supramolecular array constructed by 1D tape-like polymeric motif through aromatic π-π stacking interaction. Electrochemical investigation shows that 1 exhibits appreciable electrocatalytic activity for the reduction reaction of nitrite.
