Syntheses, crystal structures, and properties of four polyoxometalate-based metal–organic frameworks based on Ag(I) and 4,4′-dipyridine-N,N′-dioxide

Abstract

Four new metal-organic frameworks ([Ag 3 (dpdo) 3.5 (DMF)(PW 12 O 40)]•H 2 O (1), [Ag 3 (dpdo) 5 (DMF) 2 (PW 12 O 40)]•2CH 3 OH (2), [Ag 3 (dpdo) 5 (DMF) 2 (PMo 12 O 40)]•4H 2 O (3), and H 0.5 [Ag 4.5 (dpdo) 5 (DMF) (BW 12 O 40)]•5H 2 O (4); dpdo = 4,4'-dipyridine-N,N'-dioxide) based on polyoxometalates were created, and their properties were examined using infrared (IR) spectroscopy, powder X-ray diffraction, elemental analysis, and comprehensive single-crystal structure investigations. In compounds 1 and 4, the secondary building blocks ([Ag 6 O 20 ] and [Ag 3 O 14 ] for 1 and 4, respectively) serve as nodes that connect the dpdo ligands with the polyanions ([PW 12 O 40 ] 3− and [BW 12 O 40 ] 5− for 1 and 4, respectively) to create a three-dimensional (3D) framework. By joining Ag ions and dpdo ligands and enclosing the polyanions ([PW 12 O 40 ] 3− and [PMo 12 O 40 ] 3− for compounds 2 and 3, respectively) as templates and counterions, compounds 2 and 3 display a two-dimensional (2D) gridlike network. Additionally, the solid state optical, luminescent, and ultraviolet-visible (UV-vis) spectral features of compounds 1-4 as well as the electrochemical characteristics of compounds 1-3 were examined.