Concerning the existence of Hminus;ion in irradiated solvent matrices at 77 K studied by stimulated luminescence

摘要

The attribution of the sim;1050 nm stimulation luminescence (SL) band in ggr;hyphen;irradiated pure solvent matrices at 77 K to the anion Hminus;is further supported by the present SL results observed on irradiated neutral or acidic solid solutions of tetramethylhyphen;phyphen;phenylenediamine (TMPD), tryptophan, or diphenylhyphen;phyphen;phenylenediamine (DPPD) in methylcyclohexane (MCH), 4.5M CaCl2ices and 2hyphen;methyltetrahydrofuran (MTHF). Depending on the location of its SL band, at the red side or the blue side of theeminus;sone, the anion Hminus;can decay faster or slower, respectively, relative to theeminus;sin the irradiated matrix. The present two photon bleaching SL experiments in the region below the SL energy threshold support the suggestion that theeminus;soptical absorption band in ggr;hyphen;irradiated MTHF consists of many underlying discrete bands. There are three strongly overlapping bandsthinsp;:thinsp;1050, 1200, and 1400 nm. One of these, the 1050 nm, would be related to the anion Hminus;. The effect of the ggr;hyphen;dose rate on the SL intensity in irradiated TMPDndash;MCH and DPPDndash;MTHF glasses at 77 K reveals that (a) for the same total ggr;hyphen;dose the formation of solvent radical is more pronounced in samples with higher ggr;hyphen;dose rate; (b) the solvent radical anion(s) might have an optical absorption band located in the same region as theeminus;sone.