posted on 2020-03-16, 16:05authored byMarvin
K. Sarango-Ramírez, Dae-Woon Lim, Daniil I. Kolokolov, Alexander E. Khudozhitkov, Alexander G. Stepanov, Hiroshi Kitagawa
Highly
stable superprotonic conductivity (>10–2 S cm–1) has been achieved through the unprecedented solvent-free-coordinative urea insertion in MOF-74 [M2(dobdc), M = Ni2+, Mg2+; dobdc = 2,5-dioxido-1,4-benzenedicarboxylate]
without an acidic moiety. The urea is bound to open metal sites and
alters the void volume and surface functionality, which triggers a
significant change in proton conductivity and diffusion mechanism.
Solid-state 2H NMR revealed that the high conductivity
was attributed to the strengthening of the hydrogen bonds between
guest H2O induced by hydrogen bonds in the interface between
H2O and the polarized coordinated urea.