Magnetic properties of metal–quinone high-spin complexes prepared by solid-state mechano-activation and by chemical synthesis in solution. Comparative study with very high-field and low-temperature EPR and ENDORстатья
Аннотация:EPR spectroscopy at high frequencies and low temperatures and ENDOR spectroscopy at X- and W-bands have been applied toinvestigate two- and three-spin complexes of the type MQ,' and MQ3' generated by mechanochemical treatment (by grinding orby the action of elastic waves) of solid mixtures of quinones and metals (M = Al, Ga, In, Cd, Sn, Zn). In addition, complexesobtained in liquid-phase reactions of metal amalgams with quinones were investigated. The magnetic-resonance parameters andthe observed thermal spin polarization provide evidence for the identity of the magnetic complexes produced in solutions and bysolid-state mechanochemical treatment. In particular, the presence of ground-state triplet and quartet species has been demonstrated in both cases. In addition, the exchange and the dipoledipole interaction parameters were evaluated, their comparisonproviding information about the electronic intramolecular interaction.
