Electron Spin Relaxation and Heterogeneity of the 1:1 α,γ-Bisdiphenylene-β-phenylallyl (BDPA)/Benzene Complex

The electron spin spin relaxation time (T-2) for the 1:1 crystalline complex of alpha,gamma-bisdiphenylene-beta-phenylallyl (BDPA) with benzene was determined by continuous wave (CW) and rapid scan electron paramagnetic resonance (EPR). T-2 for individual BDPA particles found by simulation of rapid scan spectra or by simulation of the Lorentzian line shapes of CW spectra were in good agreement. The T-2 for small BDPA particles in air ranged from 80 to 160 ns, which corresponds to peak-to-peak Lorentzian linewidths of 0.82-0.41 G. The removal of oxygen from the samples had a greater impact on the line width for particles that had shorter T-2 in air. Heterogeneity in the g-value was not observed at X-band. Scanning electron microscope (SEM) images showed that the BDPA particles had varying morphology.