The ionothermal synthesis of a new 3-D framework based on classic β-[Mo8O26]4− anions

Abstract

An unusual metal-organic framework, {H[Ag(I)L][Mo(VI)4O13]}n (1) (L=(4-((1H-1,2,4-triazol-1-yl)methyl)phenyl)methanol)), has been obtained under ionothermal conditions. According to the single-crystal X-ray diffraction analysis, 1 is a new 3-D framework based on β-[Mo8O26]4− type polymolybdate anions with two kinds of channels (A and B) along the b-axes and c-axes in the framework. The neighboring inorganic Mo8-Ag chains are linked by the organic ligands through the Ag centers resulting in 2-D layers. These adjacent 2-D layers extend into a 3-D framework through Ag1 nodes and β-[Mo8O26]4− anions, respectively, resulting in a topological symbol (64 · 82)2(64 · 82). In addition, the gas adsorption, proton conduction and luminescent properties of 1 are also discussed in detail. Moreover, the electrochemical impedance spectroscopy (EIS) measurements show a conductivity (1.9 × 10−4 S cm−1 at 65 °C and 95% relative humidity (RH)), with an activation energy of 0.41 eV for 1. The mechanism of proton conduction for 1 is proved to be the vehicular mechanism.