| The Keggin-type POMs, as a classic member of the large family, possesses a large of terminal and bridge oxygen to combine with various transition metals to form a number of novel structures compounds with good applications. Under hydrothermal condition, on the basis of classic Keggin-type polyoxometalates, selecting the rigid ligands to modify them. Nine organic-inorganic hybrid compounds with novel structures have been synthesized and characterized by elemental analysis, TG, IR, UV and single-crystal X-ray diffraction. Additionally, their fluorescent properties, electrochemical properties, electrocatalytic properties and photocatalytic properties have been investigated. The molecular formula of the nine compounds:(H3biz)2(H2biz)2[HPMo12O40](1)(H3biz)3(H2biz)[PMo12O40](2)[{Ag7(H3biz)2(biz)4}{H2PMo12O40}]·4H2O(3)[{Ag7(H3biz)2(biz)4}{H2PW12O40}]·4H2O(4)[{Ag9(H3biz)2(biz)4}{HSi W12O40}]·2H2O(5)[{Ag12(H2L)2(HL)2L4}{HPMo12O40}]·4H2O(6)[{Ag9(HL)6}{HSiW12O40}]·6H2O(7)[Ag(pz)2]6[PMo12O40]2·3H2O(8)[Ni2(phen)4Cl][H2PMo12O40][HPMo12O40]·H2O(9)(H2biz=benzimidazole; H2L= 6-Nitrobenzimidazole; pz = pyrazol; 1,10-phen=1,10-Phenanthroline)Single-crystal X-ray diffraction studies reveals that compounds 1~9 are based on [XM12O40]n-(X = P, S; M = Mo or W) cluster anion. Compounds 1-5 are modified by benzimidazole ligands. In compound 1, {PMo12} polyanion with surrounding ligands form a supramolecular ring, it looks like a traditional Chinese knot, these “Chinese knot” units form 2D layer via hydrogen bonding interactions. Compound 2 contains two kind layers, the B layer is obtained by the 180 angle rotation of A layer, two kind layers arrange in a A-B-A-B type to form 3-D structure via supermolecular interaction. Compounds 3-5 have silver N-heterocyclic carbene groups, especially compound 3 and 4 are isostructural, seven Ag ions and six H2 biz ligands form a “Wave” geometry Ag cluster, the polyoxoanion as a template is wrapped by two Ag clusters to form a 1D chain structure via Ag-O bond. In compound 5, six ligands link nine Ag+ cations forming a “fish-like” Ag cluster, which furthermore connect with adjacent {SiW12} clusters form the holes. Compounds 6 and 7 are modified by 6-Nitrobenzimidazole ligands, also contain silver N-heterocyclic carbene groups. In compound 6, twelve Ag+ and eight L ligands form a Z-type large Ag cluster. Every Ag cluster connects to adjacent three clusters form “cage” structure with four different holes. In compound 7, six Ag+ and three L ligands compose a shell-type Ag cluster. [Si W12O40]4- polyanion is surrounded by two Ag clusters to from a charming diamond strunture. In compound 8, two crystallographically independent [PMo12O40]3- clusters are arranged in a AB-AB mode to give two kinds of supramolecular layers. The layers are further connected in a special alternating mode by [Ag(pz)2]+ linkers to form complex 3D supramolecular network. In compound 9, a butterfly structure constructed from two 1,10-phen and Ni2+, two “butterfly” connect to Cl- form [Ni2(phen)4Cl]3+ cations, [P(1)Mo12O40]3- and [P(2)Mo12O40]3- are supported by [Ni2(phen)4Cl]3+ to form an infinite wave 1D chain.Additionally, their fluorescent properties, electrochemical properties, electrocatalytic properties and photocatalytic properties of Rhodamine-B(RhB) at room temperature have been investigated. The results show that compounds 1-9 have strong fluorescent properties and can be used as luminescent materials. Compounds 1-9 have good electrochemical properties and electrocatalytic properties and it indicates the photocatalytic properties of RhB of compounds 1-9 are excellent. |
PDF Full Text Request