Four new metal-organic frameworks based on bi-, tetra-, penta-, and hexa-nuclear clusters derived from 5-(phenyldiazenyl)isophthalic acid: syntheses, structures and properties

Four new metal-organic frameworks (MOFs), namely, [Cu(PDIA)(DMA)](n) (JUC-126), [Mn-4(PDIA)(4)(DMF)(6)](n)center dot nDMF center dot 2nH(2)O (JUC-127), [Zn-23(PDIA)(18)(mu(4)-O)(2)(mu(3)-OH)(6)DMA(6)](n)center dot 10nDMA center dot 6nH(2)O (JUC-128), [Co-3(PDIA)(2) (HCOO)(mu(3)-OH)(H2O)(DMA)(2)](n)center dot nDMA center dot nH(2)O (JUC-129) (JUC = Jilin University, China), based on a new rigid ligand 5-(phenyldiazenyl) isophthalic acid (H(2)PDIA) with azobenzene were synthesized under solvothermal conditions. The ligand is connected to different metals to form bi-, tetra-, penta-and hexanuclear cores with distinctive coordination modes to generate different structures. Moreover, p-p stacking interactions between arene cores of the ligands also exist to affect the structural assembly process. JUC-126 displays a three-dimensional (3D) NbO topology with the point symbol (6(4).8(2)) based on Cu-2(COO)(4) as secondary building units (SBUs), JUC-127 shows a two-dimensional (2D) sql topology with the point symbol (4(4).6(2)) based on Mn-2(COO)(4) as SBUs, JUC-128 has a new 3D topology with the point symbol (3(3).4(6).5(6))(2)(3(6).4(8).5(10).6(4))(3) based on Zn4O(COO)(6) and Zn-5(mu(3)-OH)(2)(COO)(8) as SBUs and JUC-129 exhibits a 2D sql topology with the point symbol (4(4).6(2)) based on Co-6(mu(3)-OH)(2)(COO)(10) as SBUs. In addition, JUC-126, JUC-128 and JUC-129 are achiral frameworks; however, JUC-127 shows a chiral framework from an achiral ligand. Furthermore, the luminescent property of JUC-128 and the magnetic properties of JUC-127 and JUC-129 have been studied and discussed.