Sensitized ketonization of ethyl acetoacetate. A method for the determination of triplet quantum yields

Abstract

A new method for the determination of triplet quantum yields, QT, based on the ketonization of ethyl acetoacetate (EAA) sensitized by triplet energy transfer, is described. Steady state and fluorescence measurements were carried out, using benzene, toluene, and p-xylene as energy donors. The QT values obtained by this simple method are in very good agreement with data obtained by other methods. A probable mechanism for photoketonization is discussed.

Measurements of the Relaxation Kinetics of Photo‐Excited Enol Form of Dibenzoylmethane

“…where n,(t) is number of molecules on level i. For this four level system we write the rate equations" dn2 -k21/12 (4) dn3 -(k31 + k34)" n3 (5) dt dtl 4 k34n k41n4 (6) dt dnl k21 r12 + k31n3 + k41n4 (7) dt The solution of the system gives: n2 N2 exp (-k2 t) (8) n3 N3" exp (-kt) (9) n4 C{exp (-k4t)-exp[-(k2 + k34)t]} (10) n N N2. exp (-k2 t) C2.…”