Time-resolved thermal lensing and phosphorescence studies on photosensitized singlet molecular oxygen formation. Influence of the electronic configuration of the sensitizer on sensitization efficiency
✍ Scribed by Robert W. Redmond; Silvia E. Braslavsky
- Publisher
- Elsevier Science
- Year
- 1988
- Tongue
- English
- Weight
- 602 KB
- Volume
- 148
- Category
- Article
- ISSN
- 0009-2614
No coin nor oath required. For personal study only.
✦ Synopsis
The absolute quantum yields, QAd, of photosensitized formation of singlet molecular oxygen, O2 (I$), by various sensitizers in benzene were measured by time-resolved thermal lensing (TRTL). Relative measurements with time-resolved O,( 'Ag) phosphorescence detection were used to confirm the absolute values from TRTL. For aromatic mt* triplet states, S&G @~/Q&=0.9 k 0.1 and the rate constant for quenching of the triplet state of 02, k,= (2 + 0.5) x 10-l M9 s-l, is about l/9 of the diffusional rate constant. For the more polarizable nrc* triplet states .S,=O.3 f 0.05 and k. sharply increases with triplet energy.