Three novel polyoxometalate-based inorganic-organic hybrid materials based on 2,6-bis(1,2,4-triazol-1-yl)pyridine.

Three novel inorganic-organic hybrid materials [Co(btp) 2 (W 5 O 16 )(H 2 O)] n (1), [Cd 3 (btp) 6 (PW 12 O 40 ) 2 (H 2 O) 6 ·6H 2 O] n (2), and [Ag 3 (btp) 2 (PMo 12 O 40 )·1.5H 2 O] n (3) (btp = 2,6-bis(1,2,4-triazol-1-yl)pyridine) have been hydrothermally synthesized and characterized by IR spectroscopy, single-crystal X-ray diffraction, powder X-ray diffraction (PXRD), elemental analysis and thermal gravimetric analysis (TGA). The most striking structure feature of compound 1 is a 3D polycatenation framework, interpenetrated by a 2D 4-connected sql topology layer and a 3D 6-connected rob topology framework. Compound 2 exhibits a rare meso-helices 3D network with different chiralities crossing coexistence. Compound 3 also holds a 3D framework formed by linking terminal oxygen atoms of [α-PMo 12 O 40 ] 3- anions and silver ions in a 2D metal-organic layer. Compound 1 displays antiferromagnetic behavior. The luminescence, electrochemical and photocatalytic properties of compounds 1-3 have also been investigated. Compound 3 exhibits significant electrochemical activity for the reduction of H 2 O 2 while compounds 1 and 2 show efficient photocatalytic activities for the degradation of Rhodamine B (RhB). Furthermore, the three compounds display luminescence behaviors in the solid state.