Controllable self-assembly of two novel metal-organic frameworks based on different tetradentate in situ ligands

Two novel metal-organic frameworks (MOFs) based on different tetradentate in situ ligands, Cu-3(I)(L-1)(2)(L-2)[(PMo8V4O40)-V-VI-O-V((VO)-O-IV)(2)]center dot 2H(2)O (1) and [(Cu2Cl2)-Cl-I(L-3)] (2) (L-1 = 1,4-bis(imidazol-1-ylmethyl) benzene, L-2 = 1,2,4,5-tetra(4-pyridyl)-benzene L-3 = a-1-hydroxy-e,e,e,e-1,2,4,5-tetra-(4-pyridyl) cyclohexane) have been rationally hydrothermally synthesized and characterized by elemental analyses, IR spectroscopy, TG analyses, and single-crystal X-ray diffraction, respectively. Here, compound 1 represents the first example that dehydrogenative coupling has been employed to yield a novel tetradentate coplanar dye molecule in POM-based MOFs. It also exhibits unique 3D MOFs with two topologies (4(2)8(4))(4(2)8(3)10(1))(8(6))(2) and (4(3)8(3))(4(2)8(4))(4(4)6(2)8(9))(4(10)6(1)8(3)) due to different definitions of nodes. Compound 2 shows a two-fold diagonal/diagonal inclined interpenetration based on Cu-I ions and in situ synthesized ligands L-3. Interestingly, reaction conditions play important roles in the domination of in situ ligands (L-2 and L-3) from the same precursor bpp (bpp = 1,3-bis-(4-pyridyl) propane). Additionally, electrochemical and photocatalysis properties of compound 1 have also been minutely investigated.