LAUSR

We have studied the nature of monovalent Cd+ (4d10 5s1) species generated in a Cd-loaded HZSM-5 zeolite by reaction with molecular O2. The open-shell species formed in the different steps of the—reversible—reaction are characterized by electron paramagnetic resonance and hyperfine sublevel correlation (HYSCORE) spectroscopies at X- and Q-band frequencies. The same Cd+ species are obtained via a photochemical pathway through the UV irradiation of the Cd-loaded zeolite. Unambiguous evidence for the formation of mononuclear Cd+ species is obtained by the detection of the hyperfine interaction associated to the naturally abundant 111Cd and 113Cd magnetic isotopes (I = 1/2 natural abundance 12.8 and 12.22%, respectively). The full 111Cd A tensor (Ax = 10 620, Ay = 10 639, Az = 10 790 MHz) is resolved, indicating that 84% of the unpaired electron spin density is localized on the Cd ion. The small spin density delocalization on the zeolite framework is observed through the detection of 27Al hyperfine interaction...