Synthesis, crystal structures and electrocatalytic properties of 2D and 3D Co(Ⅱ) Coordination polymers based on semi-rigid tricarboxylic acid ligand

The tricarboxylic ligand, 4′,4′,4′-[(trimethylamino)]-tris[(1,1′-biphenyl)-2-carboxylic acid] (H 3 TMCA), is designed and synthesized to self-assembly two novel cobalt coordination polymers, formulated as {[Co 2 (TMCA)(OH)(DMF)(H 2 O)]} n (1), {[Co 3 (TMCA) 2 ]} n (2). Interesting, due to the flexibility of the H 3 TMCA, the final frameworks of 1-2 can change depending on the reaction of temperature and solvents. Complex 1 is a (3, 6)-connected of type kgd two-dimensional (2D) network with a point (Schlafli) symbol of {4 3 } 2 {4 6 . 6 6 . 8 3 }. Complex 2 is a (4, 6)-connected 2-nodal three-dimensional (3D) net with point (Schlafli) symbol of {4 15 } 2 {4 2 . 8 4 } 3 . In addition, the electrocatalytic activity of these Co-CPs were studied in detail.