Summary: 2192 J. Org. Chem. 1987, 52, 2192-2195
by determining spectrometrically the extent of ionization for
p-anisyldiphenylmethanoland correlated it with the known pKR+
value (-1.24)37of p-anisyldiphenylmethyl cation.
The ~ K R +values for the monocations and also the values
correspondingto the second neutralization of the dications were
determined at 25 "C in 50% acetonitrile by means of the UV
spectrophotometric method described in a previous paper.38
Cyclic Voltammetry. The measurements were done with the
method and apparatus described in the previous paper.% Sample
solutionswere 1 mM in cation and 0.1 M in tetrabutylammonium
perchlorate as a supporting electrolyte. Scan rate was 0.1 V/s.
All the cations exhibited the irreversible cathodic peak at the
potential given in Table V. Immediatelyafter each measurement,
ferrocene (0.2mM) was added as an internal standard,39and the
peak potential was corrected with reference to this standard.
Acknowledgment. We thank Shigeo Fujii of Tottori
University for technical assistance in the X-ray crystallo-
graphicanalysis. Helpful discussion with Professor Hiroshi
Fujimoto of Division of Molecular Engineering, Faculty