Methods for production of radical ions in low temperature matrices for electronic spectroscopy

Amine-assisted photochemical dehalogenation of haloanthracenes (9-halo and 9,10-dihalo compounds) and their triplet formation

“…We have assigned bands F, G and H to absorptions of the haloanthracene radical anions (XA'-) based on the following facts: (1) The spectra with bands F -H are identical with those of XA'which are produced by pulse radiolysis of XA at room temperature in CHaCN without amine (Hamanoue et al 1984a) or ~,-radiolysis of XA at 77 K in 2-methyltetrahydrofuran without amine. (2) Band E observed in the presence of DMA is vbry similar to that of the published absorption spectrum due to DMA "+ (Hamil 1968;Shida 1988;Iwamura and Eaton 1991); no clear observation of the absorption band due to TEA .+ may be ascribed to its weak absorption (Shida 1988).…”

Radical Cation of 1,3-Butadiene: Resonance Raman Spectrum of the h6 Isotopomer

“…6,46 Although we could reproduce the electronic absorption spectrum published previously for BD •+ in this medium, 11,13,16 we were not able to detect Raman scattering from BD •+ , except for a very weak band around 1600 cm -1 where the strongest fundamental is observed in the Freon matrix spectrum. 6,46 Although we could reproduce the electronic absorption spectrum published previously for BD •+ in this medium, 11,13,16 we were not able to detect Raman scattering from BD •+ , except for a very weak band around 1600 cm -1 where the strongest fundamental is observed in the Freon matrix spectrum.…”

“…As density functional theory calculations predict some important bands in regions masked by matrix bands, we have carried out experiments in a 1:1 mixture of isopentane (2-methylbutane) and n -butyl chloride, which also forms a transparent glass at liquid nitrogen temperature and can be utilized as a matrix material in connection with the radiolytical generation of radical cations. , Although we could reproduce the electronic absorption spectrum published previously for BD •+ in this medium, ,, we were not able to detect Raman scattering from BD •+ , except for a very weak band around 1600 cm -1 where the strongest fundamental is observed in the Freon matrix spectrum.…”

Radical Cations of Monomethyl-Substituted 1,3-Butadienes: Resonance Raman Spectra and Molecular Orbital Calculations

“…The generation of radical cations by γ-irradiation in Freon glasses is well documented. 2,12,31 The originally colorless glasses containing 1.5 × 10 -2 M trans-or cis-1,3-pentadiene turned orange-red following γ-irradiation at 77 K, while in the case of isoprene a green color indicated the appearance of the radical cations. The electronic absorption spectra of the radical cations are shown in Figure 1.…”