Series of Metal-Organic Frameworks Including Novel Architectural Features Based on a Star-like Tri(4-pyridylphenyl)amine Ligand

Six new metal-organic frameworks with novel structural features based on a star-like ligand tri(4-pyridylphenyl)amine (TPPA), namely, {[Cd(TPPA)(pht)(H2O)](H2O)(2)}(n) (1), {[Zn(TPPA)(pht)](H2O)(2)}(n) (2), {[Zn(TPPA)(trans-chdc)(0.5)(NO3)]center dot(H2O)}(n) (3), {[Co(TPPA)(bdc)(H2O)]center dot(H2O)}(n) (4), {[Co(TPPA)(bdc)(H2O)]center dot(H2O)(4)}(n) (5), and {[Co(TPPA)(bdc)]}(n) (6) (H(2)pht = phthalic acid, trans-H(2)chdc = trans-1,4-cyclohexanedicarboxylic acid, H(2)bdc = benene-p-dicarboxylic acid), have been synthesized under solvothermal conditions. Compounds 1-3 all exhibit fascinating. 2D -> 3D frameworks with coexistence of inclined polycatenation and polythreading characters. On the other hand, compounds 4-6 are three supramolecular isomers. Even though the compositions of 4-6 are almost same, they generate different structures. Compound 4 shows a 2D -> 3D framework with parallel polycatenation of undulated square layers. Compound 5 reveals 3-fold interpenetrating 3D frameworks with {4.6(2)}{4(3).6(7)} crs topology. Compound 6 shows a 4-fold interpenetrating 3D metal-organic polyrotaxane framework. In addition, photophysical properties of 1-3 and the TPPA ligand in the solid state have also been studied.