Syntheses, structures and photoluminescence of two Dawson-based hybrid materials with polynuclear silver clusters

Two new POM-based hybrids (POM = polyoxometalate), namely, [Ag6(H L)4(H2O)6(P2W18O62)]·4H2O (1) and [Ag4(H2biim)4][K2(H2O)3(P2W18O62)]·H2O (2) (HL = 5-(4-imidazol-1-yl-phenyl)-2H-tetrazole, H2biim = 2,2′-biimidazole), have been hydrothermally synthesized and characterized. X-ray diffraction analysis reveals that compound 1 is a 3D structure based on infinite organic-metal chains {Ag6(HL)4}n and Wells-Dawson anions. Compound 2 displays a 3D framework based on potassium-POM inorganic sheets and dinuclear silver-H2biim units.