Solid-State ¹⁷O NMR of Oxygen–Nitrogen Singly Bonded Compounds: Hydroxylammonium Chloride and Sodium Trioxodinitrate (Angeli’s Salt)

Abstract

We report a solid-state NMR study of (17)O-labeled hydroxylammonium chloride ([H(17)O-NH3]Cl) and sodium trioxodinitrate monohydrate (Na2[(17)ONNO2]·H2O, Angeli's salt). The common feature in these two compounds is that they both contain oxygen atoms that are singly bonded to nitrogen. For this class of oxygen-containing functional groups, there is very limited solid-state (17)O NMR data in the literature. In this work, we experimentally measured the (17)O chemical shift and quadrupolar coupling tensors. With the aid of plane-wave DFT computation, the (17)O NMR tensor orientations were determined in the molecular frame of reference. We found that the characteristic feature of an O-N single bond is that the (17)O nucleus exhibits a large quadrupolar coupling constant (13-15 MHz) but a rather small chemical shift anisotropy (100-250 ppm), in sharp contrast with the nitroso (O═N) functional group for which both quantities are very large (e.g., 16 MHz and 3000 ppm, respectively).

On the incompatibility of lithium–O2 battery technology with CO2

“… a The uncertainties in the experimental data are: δ iso ± 2 ppm; δ ii ± 10 ppm; C Q ± 0.2 MHz; η Q ± 0.1. b See ref. 24 .…”

Solid-State 15N and 17O NMR Studies of S-Nitrosothiols

“…S -Nitrosothiols (RSNO or RSNO) are a class of organic molecules that play important roles in nitric oxide (NO) chemistry, potential therapeutic applications, and protein post-translational modification. − Recently, the reactivity of RSNOs toward H 2 S under physiological conditions has attracted considerable attention − and also generated controversies. − This new reaction pathway adds further complication for possible “cross talks” between the two major gaseous signaling molecules, NO and H 2 S. Because RSNOs are generally unstable, only a limited number of X-ray structural − and 15 N ( I = 1/2) NMR spectroscopic studies ,− have been reported in the literature. In fact, all previous NMR studies of other NO-related compounds utilize 15 N as a common NMR probe nucleus. − Recently, we demonstrated the use of 17 O ( I = 5/2) as a complementary NMR probe to study NO-related compounds. − One of the advantages of 17 O NMR is that the fast quadrupolar 17 O relaxation in solution allows one to collect data very rapidly so that some transient reaction intermediates can be potentially captured. For example, we used 17 O NMR to help identify molecular structures of the elusive red-violet and blue intermediates in the Gmelin reaction between nitroprusside and sulfides in aqueous solution .…”