A Zinc(Ⅱ) Coordination Polymer Based on a Polycarboxylate Ligand: Synthesis, Crystal Structure, Photoluminescence and Photocatalysis

A new zinc coordination polymer(CP) {[Zn1.5(ttb)0.5(phen)(H2O)]·2 H2O}n(1),(H6ttb = 3,4,5-tricarboxyl-(3',4',5'-tricarboxylazophenyl)benzene, phen = 1,10-phenanthroline), has been hydrothermally synthesized and structurally characterized by single-crystal X-ray determination, IR and thermogravimetric analysis(TGA). CP 1 crystallizes in the monoclinic system, space group C2/c with a = 12.402(3), b = 15.231(3), c = 22.233(4)A, β = 94.388(3)°, Zn1.5C21H16N3O9, Mr = 552.42, V = 4187.3(15) A^3, Dc = 1.753 g/cm^3, F(000) = 2240, μ = 1.795 mm^-1, S = 1.041, GOF = 1.041, Rint = 0.0169, 2.36°<θ<30.95°, and Z = 8. The final refinement gave R = 0.0340 and w R = 0.0927 for 5791 observed reflections with I > 2σ(I). The completely deprotonated(ttb)^6- ion in 1 adopts an octadentate coordination mode(μ8-η^2-η^1-η^1-η^1-η^1-η^2). Four of the carboxyl groups are coordinated with four zinc ions by monodentate, respectively. While the other two carboxyl groups are coordinated with four zinc ions by bidentate, respectively. So, CP 1 possesses a 3 D network structure cross-linked by(ttb)6-ion. The XRD, UV and photoluminescence properties of CP 1 were also studied. Remarkably, 1 exhibits photocatalytic activities for the degradation of dye(MO) under UV light irradiation and shows good stabilities towards UV-light photocatalysis.

A new zinc coordination polymer（CP） {[Zn1.5（ttb）0.5（phen）（H2O）]·2 H2O}n（1）,（H6ttb = 3,4,5-tricarboxyl-（3?,4?,5?-tricarboxylazophenyl）benzene, phen = 1,10-phenanthroline）, has been hydrothermally synthesized and structurally characterized by single-crystal X-ray determination, IR and thermogravimetric analysis（TGA）. CP 1 crystallizes in the monoclinic system, space group C2/c with a = 12.402（3）, b = 15.231（3）, c = 22.233（4） ?, β = 94.388（3）°, Zn1.5C21H16N3O9, Mr = 552.42, V = 4187.3（15） ?3, Dc = 1.753 g/cm3, F（000） = 2240, μ = 1.795 mm-1, S = 1.041, GOF = 1.041, Rint = 0.0169, 2.36°<θ<30.95°, and Z = 8. The final refinement gave R = 0.0340 and w R = 0.0927 for 5791 observed reflections with I > 2σ（I）. The completely deprotonated（ttb）6- ion in 1 adopts an octadentate coordination mode（μ8-η2-η1-η1-η1-η1-η2）. Four of the carboxyl groups are coordinated with four zinc ions by monodentate, respectively. While the other two carboxyl groups are coordinated with four zinc ions by bidentate, respectively. So, CP 1 possesses a 3 D network structure cross-linked by（ttb）6-ion. The XRD, UV and photoluminescence properties of CP 1 were also studied. Remarkably, 1 exhibits photocatalytic activities for the degradation of dye（MO） under UV light irradiation and shows good stabilities towards UV-light photocatalysis.