Ultrahigh-field <sup>67</sup> Zn NMR reveals short-range disorder in zeolitic imidazolate framework glasses
Rasmus S. K. Madsen, Ang Qiao, Jishnu Sen, Ivan Hung, Kuizhi Chen, Zhehong Gan, Sabyasachi Sen, Yuanzheng Yue
Abstract
The structure of melt-quenched zeolitic imidazole framework (ZIF) glasses can provide insights into their glass-formation mechanism. We directly detected short-range disorder in ZIF glasses using ultrahigh-field zinc-67 solid-state nuclear magnetic resonance spectroscopy. Two distinct Zn sites characteristic of the parent crystals transformed upon melting into a single tetrahedral site with a broad distribution of structural parameters. Moreover, the ligand chemistry in ZIFs appeared to have no controlling effect on the short-range disorder, although the former affected their phase-transition behavior. These findings reveal structure-property relations and could help design metal-organic framework glasses.