Journal of the American Chemical Society, Vol.120, No.41, 10622-10628, 1998
Self-assembly of molecular brick wall and molecular honeycomb from nickel(II) macrocycle and 1,3,5-benzenetricarboxylate : Guest-dependent host structures
Novel multidimensional supramolecular networks with brick wall and honeycomb structures, [Ni(C12H30N6O2)](3)[C6H3(COO)(3)](2). 18H(2)O (1) and [Ni(C12H30N6O2)](3)[C6H3(COO)(3)](2). 14H(2)O . 2C(5)H(5)N (2), respectively, have been constructed by the self-assembly of S = 0 Ni(II) macrocyclic complex containing hydroxyl pendent chains and I,3,5-benzenetricarboxylate (BTC3-). The host structures assembled are greatly affected even by the partial change of the guests. X-ray crystal structures indicate that each Ni(II) macrocycle binds two BTC3- in the trans position and each BTC3- coordinates three NI(II) macrocyclic units via C-1 symmetry in 1 and C-3 symmetry in 2. The simplest cyclic motif of the two-dimensional (2-D) networks in 1 and 2 is a large ring consisting of six Ni(TI) macrocyclic complexes and six BTC3- anions. The rings are extended to form a 2-D layer. The layers are stacked in parallel, separated by 8.850 Angstrom in 1 and 8.973 Angstrom in 2. They are interconnected by the hydrogen-bonding interactions between the hydroxyl pendants of the macrocycle in a layer and the secondary amines of the macrocycle located in the neighboring layers, which gives rise to the three-dimensional structures. The effective cavity size of 1 is ca. 6.7 x 13 Angstrom and that of 2 ca. 11.4 x 11.4 Angstrom. The cavities are filled with guest molecules. In 2, the pyridine guest experiences pi-pi interaction with the benzene ring of BTC3-. Variable-temperature (2-300 K) magnetic susceptibility measurements indicate chat both 1 and 2 exhibit weak anti-ferromagnetic interactions between the S = 1 Ni(II) paramagnetic centers.
Keywords:METAL-ORGANIC FRAMEWORK, CRYSTAL-STRUCTURES, COORDINATIONCHEMISTRY, POROUS SOLIDS, COMPLEXES, NETWORK, ARCHITECTURE;CHANNELS, CONSTRUCTION, PYRAZINE