The ESR method was used to study the interaction of thiophene compounds with Cu(II) ions in Mordenite.
In the dehydrated Cu(II) Mordenite, Cu(II) ions seemed to be located at magnetically equivalent one site on behalf of straight channel system in Mordenite.
When adsorption began, new Cu(II) peak was appeared and was explained by stacking fault of thiophene.
As Cu(II) concentration in Mordenite can be controlled, ESR spectral shape change by ion exchange concentration observed effectively. The higher Cu(II) ion concentration, the poorer resolution of thiophene.
When thiophene ring acted as electron donor to Cu(II), we could observe that ring electron near S-atom in thiophene ring preferentially is donated to the Cu(II) by HFSC value of thiophene.
In methyl substituted thiophene, HFSC value was generally increased by electron donation of methyl substituted to the thiophene ring.
By this HFSC value, we could observe that 3-methyl thiophene makes more stable radical cation than 2-methyl thiophene.
