ELECTRONIC STATES OF CIS-DECALIN AND TRANS-DECALIN RADICAL CATIONS IN ZEOLITES

The radical cations of cis-and trans-decalin have been studied in different synthetic zeolite matrices by EPR spectroscopy. The radical cations were produced by gamma-radiolysis at 77 K. The first experimental observation of both the electronic states (2A1: a(4H) = 50 G and 2A2: a(4H) = 29 G) of the cis-decalin radical cation is reported. The 2A1 and 2A2 states were observed at different temperatures in silicalite S-115. In ZSM-34 and Na-OMEGA-5 one species was observed preferentially, while in offretite a fast exchange between the two states was observed. In Na-Y and Na-X the 2A2 state was the principal species observed. In addition, the bridge-head neutral radical species resulting from ion-molecule reactions was observed. For trans-decalin+., the 2A(g) was observed in ZSM-34, and the 2B(g) state was observed in Na-OMEGA-5. In silicalite, only the 2A(g) state was observed at low temperature. The results for cis- and trans-decalin+. in offretite, Na-Y and Na-X were similar. The stabilization of radical cations via matrix interactions is discussed.