Two 2D Zinc(II) Coordination Polymers and Their Orange IV Composites: Preparation, Structures, and Photocurrent Responses

Reactions of Zn(OAc)2·2H2O with N1,N4-bis(5-fluoropyridin-3-yl)succinamide (bfps) and 1,2,3-benzenetricarboxylic acid (1,2,3-H3BTC) or 1,3,5-benzenetricarboxylic acid (1,3,5-H3BTC) under hydrothermal conditions produce two Zn(II)-based coordination polymers (CPs), {[Zn3(bfps)(1,2,3-BTC)2(H2O)6]·4H2O}n (1·4H2O) and {[Zn(bfps)(1,3,5-HBTC)]·H2O}n (2·H2O). Both compounds show two-dimensional layer structures derived from interconnecting dinuclear [Zn2(1,2,3-BTC)2(H2O)2] units through the bfps bridges and the [Zn(H2O)4] species (1·4H2O) or interlinking dinuclear [Zn2(1,3,5-HBTC)2] units via pairs of bfps bridges and pairs of 1,3,5-HBTC dianions (2·H2O). They display high absorptive capacities toward Orange IV (OIV) in water, i.e., 718 mg·g–1 (1·4H2O) and 794 mg·g–1 (2·H2O), respectively. The resulting CP-OIV composites with the chemical formulas of 1·2.0OIV (3) and 2·1.1OIV·2.5H2O (4) exhibit enhanced photocurrent responses in relation to those of the two precursors.