Pulsed EPR study of the (NO)2–Na+ triplet state adsorption complex

The (NO)2–Na+ triplet state complex stabilised in Na–A zeolites at low temperature was studied by pulsed EPR. The 3-pulse ESEEM spectra at 5 K were analysed by simulations in the time-domain, followed by Fourier transformation. The ESEEM was attributed to the interaction with Na+. The hyperfine coupling A(23Na) = (4.6, 4.6, 8.2) MHz and nuclear quadrupole Q(23Na) = (0.3, 0,3, −0.6) MHz tensors are of comparable magnitude as in the NO–Na+ complex determined earlier. The complexes are proposed to be either pairs of NO–Na+ or ON–Na+–NO.