Inorganic Chemistry, Vol.43, No.14, 4383-4386, 2004
Unusual enlargment of magnetic interactions in the lowest excited states of nitroxide radical chromium(III) complexes as revealed by magnetic circular dichroism and luminescence
Magnetic circular dichroism and NIR luminescence of nitroxide radical complexes, [Cir(III)(beta-diketonato)(2)(NIT2py or IM2py)]PF6, demonstrate that the energy gaps between the singlet (L-1(D)) and triplet (L-3(D)) spin coupled levels in the lowest excited E-2(g),T-2(1g) states are much larger than those in the ground state. This is the first observation of magnetic interactions in the excited states of radical complexes, which could be elucidated in terms of the exchange mechanism.