Optical absorption spectroscopic study on solute-solvent interactions of 4,4'-bpyH radical in sub- and supercritical water

Lin, M.; Katsumura, Yosuke; Muroya, Yusa*; Fu, H.*; Yan, Y.*

The absorption spectrum of 4,4'-bpyH has been investigated in sub- and supercritical water (T = 374 C, P = 22.1 MPa) by pulse radiolysis techniques. The spectrum shows blue-shift with increasing temperature at a fixed pressure or with decreasing pressure at a fixed temperature. We have demonstrated that the shift is mainly due to the change of the dielectric constant of water. The local density effect on the absorption spectrum has been observed as well.