Chemilumineszenz von Oxydationsreaktionen

Studies on the Generation of Electronic Excitation States in a Riboflavin-Hydrogen Peroxide-Copper-Ascorbate Redox System Leading to Chemiluminescence and/or Aromatic Hydroxylation*

“…We emphasize this feature since the exothermicities of these oxygen-yielding reactions may be sufficient to promote molecular oxygen to its electronically excited states, which, may in turn be important in chemiluminescent and aromatic hydroxylation reactions. Stauff and Schmidkunz (1962), Stauff (1965), and Khan and Kasha (1966) have discussed those mechanisms whereby excited molecular oxygen species, by concerted action, can pool their energies to yield chemiluminescence in the visible and near-ultraviolet electromagnetic spectrum. Arnold et al (1965) have discussed those features of excited singlet oxygen, such as its 1-hr half-life and its high affinity for olefinic groups which may make it a likely candidate for the primary reactant leading to aromatic hydroxylation.…”

Singlet molecular oxygen. A new kind of oxygen

“…10 Based on a wavelength coincidence of this narrow band emission with liquid oxygen spectra, Stauff and Schmidkunz in 1962 suggested that the emission was a double molecule, [(1Ag)(1Ag)] -* [(32g-)(32g-)], transition involving molecular oxygen. 11 Khan and Kasha in 1963 reported a spectrum of the hydrogen peroxide-hypochlorite reaction, (H2O2/OCI-), containing a band at 6334 Á and an additional band of stronger intensity at 7032 Á (see Figure 1A, third spectrum).4 Based on the fact that the band separation, 1567 cm-1, correlated with the ground state vibrational frequency of molecular oxygen and the fact that the isotope studies of Cahill and Taube showed that the oxygen-oxygen bond of H2O2 remained intact in the molecular oxygen generated in the reaction, 12 Khan and Kasha identified the red chemiluminescence as emission from the singlet excited states of molecular oxygen. Because of the energetics of the emission, the spectral the aqueous reaction at 20 °C of 202/00 .…”

“…Generally in vitro chemiluminescence reactions are characterized by (1) a requirement for molecular oxygen or peroxide, (2) an apparent square dependence of the light intensity on the peroxide decomposition, and (3) a lu- the organic molecule. [5][6][7][8][9][10][11][12][13][14][15] The difficulty in understanding these chemiluminescence reactions involves the energetics of the reaction; a blue photon, for example, has about 70-80 kcal mol-1 of energy, but the H2O2/OCI"-reaction produces only about 32 kcal mol-1.…”

Intermolecular electron exchange

“…Taking again naphthalene as an example, with Hu ca 50 cm-1 and a ~10 cm-1, we obtain for reaction 14 with AS 8000 cm-1. P(%+) ~0.6 X 1012 sec-1 (17) This result shows that the condition ß « a is not fulfilled and that the real value is even higher.…”