Ionization Processes in Polar Solution of Tryptophan at 77° K

Abstract

The triplet absorption spectrum of tryptophan in ethylene-glycol/water glass at nOK has been registered. It is demonstrated that light of wavelength 250 nm produces trapped electrons by a two-photon process in this system. In both UV-and X-ray-induced ionization the probability that an ejected electron will recombine with its mother ion is around 0.5. Bleaching with visible light causes the trapped electrons to react with the solvent and there is also a considerable degree of retrapping. The retrapping becomes more probable when the temperature increases.

Flash Photolysis of Tryptophan and N‐acetyl‐l‐tryptophanamide; The Effect of Bromide on Transient Yields

“…Assuming that T-T annihilation is diffusion-controlled (i.e., k N 10"M-'s-'), it is estimated that the 3Trp E~~~ rr 5 x 103M-' cm-' which is in good agreement with the estimate of 6.5 x 103~-1cm-1 obtained with indole in cyclohexane by pulse radiolysis methods (Bensasson and Land, private commun. ) and with the value of 8 x 103M-'cm-' obtained by Moan (1971) at low temperatures. Figure 3 shows that k, (or the 3Trp lifetime-') varies linearly with (Trp).…”