The construction of a new POMs-based inorganic–organic hybrid framework involving in-situ ligand conversion from 1,3-bis(4-pyridyl)propane to isonicotinic acid

A new inorganic–organic hybrid complex, Na2[{Ag10(NC5H4COO)8(H2O)6}(SiW12O40)] (1), has been successfully synthesized from [SiW12O40]4− anions, Ag+ ions and 1,3-bis(4-pyridyl)propane under hydrothermal conditions and characterized by elemental analyses, IR spectroscopy, TG analyses, and single-crystal X-ray diffraction. In complex 1, each [SiW12O40]4− anion connects with six Ag atoms and in turn each Ag atom links to three [SiW12O40]4− anions, leading to a (6, 3) layer. Such (6, 3) layers are arranged in parallel and further linked by [Ag(H2O)(NC5H4COOH)2]− fragments to generate a 3D framework. The most striking feature in this work is that 1,3-bis(4-pyridyl)propane converses to isonicotinic acid in the synthetic reaction of 1, which may be induced by the combined function of Ag+ ion and polyoxometalate.

Graphical abstractIn this article, under the hydrothermal reaction conditions, we synthesized one inorganic–organic hybrid compounds. Compound 1 exhibits three-dimensional (3D) network. Furthermore, compound 1, it exists two kinds of channels, the first type, existing Ag–IN chains (pink stick), in the second type, resided the Na (I) metal ions (yellow stick).Figure optionsDownload full-size imageDownload as PowerPoint slideResearch highlights► In this paper, we synthesized a new hybrid complex from [SiW12O40]4− anions, Ag+ ions and 1,3-bis(4-pyridyl)propane. ► [SiW12O40]4− anions connect with Ag atoms to generate a (6, 3) layer. ► The transformation from 1,3-bis(4-pyridyl)propane to isonicotinic acid due to the introduction of Ag+ ion and polyoxometalate.