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.
A discrete centrosymmetric （H2O）20（CH3OH）4 binary cluster was confined in the cavity of a metaMigand hybrid [Ag4（bpda）2（bpp）4＂ 14H2O.2CH3OH], （1） （where bpp = 1,3-bis（4-pyridyl）propane and H2bpda = 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 （H2O）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
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 （lr,4r）-1,4-dimethylcyclohexane, is unambiguously trapped in a 2D Cu（II） mixed-ligand coordination polymer, {[Cu2（bpp）2（HzO）2（bpda）2]＇6H2O}n （1） （bpp = 1,3-bis（4-pyridyl）propane and H2bpda = 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
