TRIPLET-TRIPLET ABSORPTION SPECTRA AND EXTINCTION $COEFFICIENTS^{*}$

$^{*}$Supported by the School of Aeroscpace Medicine, Aerospace Medicine, Aerospace Medical Division, Brooks Air Force Base, Texas. $^{1}$Moore, R. S. and M. W. Windsor. This symposium, 1962, paper E3; \emph{Spectrochimica Acta}, 18, 1384 (1962).Author Institution: Space Technology Laboratories, Inc.“A Cary Model 14 Spectophotometer has been modified to permit recording the absorption spectra of materials while they are being irradiated with light from an AH6-mercury are. Using rods of plastic containing dissolved aromatic $compounds^{1}$, triplet-triplet absorption spectra have been recorded for naphthalene, anthracene, chrysene, coronene and several other aromatic hydrocarbons. In some cases the corresponding depletion of the ground absorption is also detectable, which makes it possible to calculate the extinction coefficient of the triplet-triplet transition.