Hydrothermal syntheses, crystal structures and characterization of two new 1-D and 2-D inorganic-organic hybrid polyoxomolybdates [H2dap]2[x-Mo8O26]•2H2O and [Cu(dap)2]2[β-Mo8O26]

Two new 1-D and 2-D inorganic-organic hybrid polyoxomolybdates [H(2)daP](2)[x-Mo8O26] center dot 2H(2)O (1) and [Cu(dap)(2)](2)[beta-Mo8O26] (2) (dap = 1,2-propanediamine) have been hydrothermally synthesized and structurally characterized by elemental analyses, IR spectra, powder X-ray diffraction and single-crystal X-ray diffraction. The most remarkable structural differences between them are that 1 displays a 1-D chain constructed from [x-Mo8O26](4-) clusters through two terminal O atoms from adjacent [x-Mo8O26](4-) clusters whereas 2 demonstrates the 2-D extended layer made up of [beta-Mo8O26](4-) clusters via [Cu(dap)(2)](2+) connectors. To our knowledge, the [x-Mo8O26](4-) cluster in 1 is reported for the first time. The thermogravimetric (TG) curve of 1 shows a two-step weight loss whereas the TG decomposition of 2 only proceeds in one stage. Additionally, their electrochemical behaviors and their photocatalytic degradation properties towards rhodamine-B are also investigated. (C) 2015 Elsevier B.V. All rights reserved.