Keggin型多酸基超分子化合物H_(3)[{H(4-AP)}_(6)(PMo^(Ⅴ)_(6)Mo^(Ⅵ)_(6)O_(40))]的结构和电催化性能

Structure and Electrocatalytic Performance of a Keggin-Type Polyoxometalate-Based Supramolecular Complex H_(3)[{H(4-AP)}_(6)(PMo^(Ⅴ)_(6)Mo^(Ⅵ)_(6)O_(40))]

通过水热合成方法,以钼酸铵、氯化镍和4-氨基吡啶为原料成功合成了一个Keggin型多酸基超分子化合物H_(3)[{H(4-AP)}_(6)(PMo^(Ⅴ)_(6)Mo^(Ⅵ)_(6)O_(40))](4-AP=4-氨基吡啶)。该化合物的结构单元包含一个[PMo^(Ⅴ)_(6)Mo^(Ⅵ)_(6)O_(40)]^(9-)阴离子和6个质子化的配体。而[PMo^(Ⅴ)_(6)Mo^(Ⅵ)_(6)O_(40)]^(9-)阴离子与配体之间通过N(1)—H(1)…O(3)、N(2)—H(2A)…O(5)和N(2)—H(2B)…O(1)三种氢键相互作用,进而形成二维超分子层。通过X射线单晶衍射、IR和粉末X射线衍射对其进行表征。晶体结构分析表明:该标题化合物属于三方晶系,R-3空间群,a=2.1912(10)nm,b=2.1912(10)nm,c=1.0423(5)nm,α=β=90°,γ=120°,V=4.3338(4)nm^(3),Z=3,R_(1)=0.0362,wR_(2)=0.0956,电催化性质研究表明该标题化合物对H_(2)O_(2)和K_(2)Cr_(2)O_(7)具有良好的电催化还原效果,以及对抗坏血酸具有良好的电催化氧化效果。

A Keggin-type polyoxometalate-based supramolecular complex H_(3)[{H(4-AP)}_(6)(PMo^(Ⅴ)_(6)Mo^(Ⅵ)_(6)O_(40))](4-AP=4-aminopyridine)was successfully synthesized from ammonium molybdate,nickel chloride,and 4-aminopyridine by hydrothermal method.The structural unit of the complex contains a[PMo^(Ⅴ)_(6)Mo^(Ⅵ)_(6)O_(40)]^(9-) anion and six protonated ligands.[PMo^(Ⅴ)_(6)Mo^(Ⅵ)_(6)O_(40)]^(9-)anion and ligands are connected to each other by N(1)—H(1)…O(3),N(2)—H(2A)…O(5),and N(2)—H(2B)…O(1)hydrogen bonds,which further form a two-dimensional supramolecular layer.It was characterized by X-ray single crystal diffraction,IR spectra,and powder X-ray diffraction.The crystal structure analysis shows that the complex belongs to the trigonal crystal system,R-3 space group,a=2.1912(10)nm,b=2.1912(10)nm,c=1.0423(5)nm,α=β=90°,γ=120°,V=4.3338(4)nm^(3),Z=3,R_(1)=0.0362,wR_(2)=0.0956.The electrocatalytic performance shows that the complex has a good electrocatalytic reduction effect on H_(2)O_(2) and K_(2)Cr_(2)O_(7).It also has a good effect of electrocatalytic oxidation on ascorbic acid.