Engineering lanthanide-optical centres in IRMOF-3 by post-synthetic modification

Abstract

The use of the post-synthetic modification of metal–organic frameworks is a recent strategy for engineering the coordination sphere of lanthanide cations and optimizing the light-emission properties of organic–inorganic hybrid materials. Here, IRMOF-3 was modified with 2-chloroacetic acid, glyoxylic acid, diethyl (ethoxymethylene)malonate and methyl vinyl ketone (vapour) and characterized by elemental analysis, solution and solid-state NMR, Fourier transform infrared spectroscopy, powder X-ray diffraction and scanning electron microscopy. The yields of the amino group's conversion were, respectively, 100% (IRMOF-3-CA), 75% (IRMOF-3-Gl), 80% (IRMOF-3-EM), and 76% (IRMOF-3-MVK). The reductive amination of IRMOF-3-Gl was carried out using sodium triacetoxyborohydride. The modified IRMOF-3 pendant groups were used to coordinate Eu³⁺ and Nd³⁺ and generate infrared (and visible) light emission.