Three Polyoxometalate-Based Coordination Polymers Constructed from the Same Dimetallic Cyclic Building Block

• Published in: European journal of inorganic chemistry 2015-01, Vol.2015 (3), p.488-493
• Main Authors: Gu, Min, Ren, Yuanhang, Hu, Yichen, Tang, Min, Kong, Zuping, Yue, Bin, He, Heyong
• Format: Article
• Language: English
• Subjects: Acetal resins; Bridging ligands; Coordination polymers; Copper; Electrochemical analysis; Hydrothermal synthesis; Ligands; Nickel; Nicotinic acid; Polyoxometalates; Voltammetry
• ISSN: 1434-1948; 1099-0682
• DOI: 10.1002/ejic.201402938

The reactions of silicotungstate, 2,5‐bis(3‐pyridyl)‐1,3,4‐oxadiazole (3‐bpo), and copper, cobalt, or nickel acetate under hydrothermal condition yield the three compounds [(SiW12O40)Cu2(3‐bpo)2(C5H4NCOOH)2]·H2O (1), [(SiW12O40)Co2(3‐bpo)2(C5H4NCOOH)2(H2O)2]·2H2O (2), and [(SiW12O40)Ni2(3‐bpo)2(C5H4NCOOH)2(H2O)2]·3H2O (3), respectively, in which the nicotinic acid ligands are generated from the in situ decomposition of 3‐bpo during the hydrothermal process. In the three structures, the polyoxometalate (POM) serves as the center and is imbedded within the dimetallic cyclic [M2(3‐bpo)2(C5H4NCOOH)2]4+ moiety through coordination bonds to form infinite one‐dimensional (1D) supramolecular snadwich‐like structures. Owing to the difference in the metal ions, the packing style of [Cu2(3‐bpo)2(C5H4NCOOH)2]4+ is different from that of [M2(3‐bpo)2(C5H4NCOOH)2]4+ (M = Co, Ni). The electrochemical behaviors of compounds 1–3 were studied by cyclic voltammetry. Three polyoxometalate‐based (POM‐based) coordination polymers containing a similar type of building block, [M2(3‐bpo)2(C5H4NCOOH)2]4+ [M = Cu, Co, Ni; 3‐bpo = 2,5‐bis(3‐pyridyl)‐1,3,4‐oxadiazole], are hydrothermally synthesized. These polymers are characterized, and their electrochemical behaviors are studied by cyclic voltammetry.