Adsorption of nitric oxide – NO – in the MOFs Cu3(btc)2 (HKUST-1) and Cu3(NH2btc)2 (UHM-30) was studied via 1H solid-state NMR. Changes to the electronic properties by adding paramagnetic molecules to antiferromagnetically coupled copper ions is evident in 1H NMR shift, hyperfine coupling, and spin-lattice relaxation times (T1). Furthermore, in the case of Cu3(NH2btc)2, the results indicate the formation of NONOates.