15N,13C and1H NMR study of azo coupling products from diazonium salts and enaminones

Abstract

Reactions of diazonium salts with 4‐substituted phenylaminopent‐3‐en‐2‐ones produce the corresponding 4‐phenylimino‐3‐phenylhydrazonopentan‐2‐ones. On the other hand, the reaction of diazonium salt with 4‐amino(or 4‐methylamino)pent‐3‐en‐2‐one gives a mixture of two isomers approaching the tautomeric form of 4‐amino‐3‐phenylazopent‐3‐en‐2‐ones. The tautomeric form of the individual coupling products was determined by means of 13C and 15N NMR chemical shifts and J(15N,H) coupling constants. With the help of TPPI‐NOESY spectra it was possible to follow the rate of mutual exchange of four protons of NH groups in both isomers of 4‐amino‐3‐(4‐methylphenylazo)pent‐3‐en‐2‐one. Copyright © 2000 John Wiley & Sons, Ltd.

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

“…These two signals appear in the typical 15 N chemical shift range of N=Ntype compounds. 57,60 Therefore, this is the first report of NONOate signals by solid-state NMR in a porous system. On the basis of signal intensity, the signal at −72 ppm could also indicate a decomposition product.…”