Nitric Oxide Adsorption in Cu3btc2-Type MOFs—Physisorption and Chemisorption as NONOates

The adsorption of the biologically important signaling molecule nitric oxide (NO) on two metal–organic frameworks (MOFs), Cu 3 btc 2 and Cu 3 (NHEtbtc) 2, has been studied by multinuclear solid-state NMR. N -Diazenium diolate (NONOate) formation as primary mode of NO adsorption in the latter MOF is concluded from 15 N, 1 H, and 13 C NMR spectra together with analysis of the 1 H spin–lattice relaxation time ( T 1 ). Furthermore, NO adsorption at the open metal site of Cu 3 btc 2 as well as Cu 3 (NHEtbtc) 2 is also evident, indicating both physisorption and chemisorption of nitric oxide.