High-Symmetry Co/Ni Triazine Polycarboxylate Diverse Frameworks Constructed by M x (COO) y Building Blocks: Characterization and Catalytic Performance Evaluation of p -Nitrophenol.

Three new triazine compounds [Co 1.5 (H 3 TDPAT)(H 2 O) 3 ]·6H 2 O ( 1 ), [Co 2 (TCPT)(μ 2 -H 2 O) 2 ]·OH ( 2 ), and [Ni 3 (TCPT)]·3OH ( 3 ) were designed and synthesized via the reaction of the symmetrical triazine ligand connected by C-N-C and C-O-C bonds with triazine poly(carboxylic acid)s ligands as the side arms: H 6 TDPAT (H 6 TDPAT = 2,4,6-tris(3,5-dicarboxylphenylamino)-1,3,5-triazine) and H 3 TCPT (H 3 TCPT = 2,4,6-tris(4-carboxyphenoxy)-1,3,5-triazine) as well as the corresponding metal salts under the solvothermal condition. Three triazine polycarboxylate frameworks were characterized by elemental analysis, infrared spectroscopy, ultraviolet spectroscopy, thermogravimetric analysis, X-ray powder diffraction, and solid fluorescent spectra in detail. The structural analysis results showed that the three-dimensional porous cage framework of compound 1 was constructed by three different polyhedral cages connected with [Co(COO) 4 (H 2 O) 2 ] building blocks. One of the compounds, 2 , is formed by twin propeller Co 2 (μ 2 -H 2 O)(COO) 3 building blocks connecting two-dimensional layers and the intermolecular π-π interactions involved the triazine rings between the layers. While the structure of compound 3 is similar to that of 2 , assembly is by Ni(COO) 3 building blocks and adjacent layers of the face-to-face π-π interaction between the triazine rings. In order to explore functional properties, the catalytic reduction of p -nitrophenol (PNP) of compounds 1 - 3 was investigated. They exhibit excellent catalytic activity of more than 95% for reduction of PNP with a dose of 2.5 mg of the compounds.