Synthesis, Structure, and Properties of Two Supramolecular Compounds Based on Silicotungstic Acid and Transition Metal(II) Coordinated Isonicotinic Acid

• Published in: Chinese journal of chemistry 2012-04, Vol.30 (4), p.759-764
• Main Authors: Kong, Zuping, Wang, Chunling, Ren, Yuanhang, Gu, Min, Hu, Yichen, Yue, Bin, He, Heyong
• Format: Article
• Language: English
• Subjects: crystal structure; HINA; Hydrogen bonds; polyoxometalates; transition metal ions
• ISSN: 1001-604X; 1614-7065
• DOI: 10.1002/cjoc.201100439

Two compounds, namely [Cd(HINA)2(µ2‐H2O)(H2O)2]2[SiW12O40]·6H2O (1) and [Co(HINA)3(H2O)3][Co(HINA)2(H2O)4][SiW12O40]·2H2O (2), have been synthesized from the aqueous mixture containing H4SiW12O40, isonicotinic acid (HINA), and M(CH3COO)2 (M=Cd and Co). The compounds have been characterized by elemental analysis, IR spectroscopy, TG analysis, and single‐crystal X‐ray diffraction. The dinuclear coordinated cadmium units in compound 1 are linked to form 2D layer parallel to ab plane through π‐π interactions and hydrogen bonds. Compound 2 contains two different types of coordinated metal cations, [Co(HINA)3(H2O)3]2+ and [Co(HINA)2(H2O)4]2+, which construct 2D layer along bc plane through π‐π interactions and hydrogen bonds. In both compounds, the Keggin anions are located inside the channels and cavities formed from stack of the coordinated metal cations, which further achieve the 3D supramolecular structure through hydrogen bonds. The luminescent property of compounds 1 and 2 has been investigated. Two supramolecular compounds based on polyoxometalates, isonicotinic acid, and metal cations (Cd and Co) show 1D channels and cavities, respectively, constructed by the coordinated metal cations through π‐π interactions and hydrogen bonds. Keggin anions play the template role inside the channels and cavities to achieve 3D frameworks.