CHEMILUMINESCENT MATERIALS.

Progress toward the development of efficient chemiluminescent systems is reported. Nine new oxalate esters and nine oxamides were prepared and examined qualitatively for chemiluminescence. Six of the esters and two oxamides gave medium or better chemiluminescent intensities when reacted with hydrogen peroxide and 9, 10-diphenylanthracene. Strong chemiluminescence was observed for two esters which represent new sub-classes of chemiluminescent oxalates. One of these requires acid catalysis and permits lifetime variation through pH control. A different, but partially overlapping, set of nine oxalate esters were examined quantitatively for chemiluminescence efficiency and lifetime in several solvents under a variety of conditions. Bis2,4-dinitrophenyl oxalate provided a quantum yield of 16.5 in dilute solution five other esters gave quantum yields above 12 and two others gave quantum yields in the 8 to 10 range. In every case, however, the quentum yield decreased with increasing ester concentration so that maximum radiation capacities were obttained at concentrations near 0.01 M. It was found that a large range of emission lifetimes can be achieved depending on the structure of the ester and the choice of reaction conditions. Author