Optical properties of a melt-quenched metal-organic framework glass

Metal-organic framework (MOF) glasses are characterized by the possession of both inorganic and organic components, linked in a continuous network structure by coordination bonds. To the best of our knowledge, the optical properties of MOF glasses have not been reported until now. In this work, we prepared a transparent bubble-free bulk MOF glass, namely, the ZIF-62 glass (ZnIm_2-xbIm_x), using our newly developed hot-pressing technique, and measured its optical properties. The ZIF-62 glass has a high transmittance (up to 90%) in the visible and near-infrared wavelength ranges, which is comparable to that of many oxide glasses. Using the Becke line n_D method, we found that the ZIF-62 glass exhibits a refractive index (1.56) similar to most inorganic glasses, though a lower Abbe number (∼31).