Structural Diversity for a Series of Novel Zn Metal-Organic Frameworks Based on Different Secondary Building Units

The secondary building unit (SBU) has been identified as a useful tool in the synthesis of metal-organic frameworks (MOFs). Herein, we synthesized six novel Zn complexes, namely, {[Zn-3(tci)(2)(DMF)(2))]center dot 2DMF center dot 2CH(3)OH}(n) (1), {[Zn-3(tci)(2)(DMSO)(2)-(H2O)(2)]center dot 2DMSO center dot 3H(2)O}(n) (2), {[ZnNa(tci)(H2O)]center dot 2H(2)O}(n) (3), {[Zn-5-(tci)(2)(OH)(4)(H2O)(2)]center dot 2H(2)O}(n) (4), {[Zn-3(tci)(2)(phen)(2)(H2O)(2)]center dot 4H(2)O}(n) (5), and {[Zn-3(tci)(2)(btb)(2)(H2O)(2)]center dot 6H(2)O}(n) (6) by utilizing different SBUs (tci = tris(2-carboxyethyl) isocyanurate, phen = 1,10-phenanthroline, btb = 1,4-bis (1,2,4-triazole-1-ylmethyl) benzene). Complexes 1-4 were synthesized only by changing solvents, and complexes 5 and 6 were obtained by adding different auxiliary ligands on the same conditions. Structural analyses show that complexes 1 and 2 possess two-dimensional (2D) structures based on linear and triangular trinuclear Zn clusters. Complexes 3 and 4 exhibit 2D and three-dimensional (3D) frameworks built on rare infinite rod-shaped SBUs, while complex 5 belongs to a 3D framework with two kinds of left- and right-helical chains built from discrete dinuclear Zn clusters and mononuclear Zn atoms. Complex 6 exhibits high-connected 3D framework based on extended linear trinuclear Zn clusters.