Enhanced Resolution of Close g Values in the High-Field, High-Frequency EPR Compared to the X-Band
EPR spectrum of [Cu2Zn2(NH3)2Br2(HL)4]Br2 · CH3OH
where HL- is the anion of diethanolamine, H2L
The X-band EPR spectrum (above) of [Cu2Zn2(NH3)2Br2(HL)4]Br2 · CH3OH in which two copper ions are exchange-coupled, was uninterpretable because of extensive overlap of the "parallel" and "perpendicular" features. High-field EPR spectrum (below) allowed the determination of the spin Hamiltonian parameters of the spin-triplet state:
gx = 2.053, gy = 2.055, gz = 2.251, |D| = 101∙10-4 cm-1 ,
|E| = 6∙10-4 cm-1, Ax = Ay = 0, Az = 94∙10-4 cm-1
Separate coordinate frames were used for tensors g and D in that gzz is perpendicular to Dzz.