Actions for Mechanism of phosphorescence quenching in photomagnetic molecules determined by positron annihilation spectroscopy

Email RIS file
Bookmark
Report an Issue

Mechanism of phosphorescence quenching in photomagnetic molecules determined by positron annihilation spectroscopy

Author
Naidu, S. V. N.
Published
Nov. 12, 1994.
Physical Description
1 electronic document
Additional Creators
Singh, Jag J. and Eftekhari, A.
Online Version

Availability

I Want It
I Want It

Finding items...

Restrictions on Access
Unclassified, Unlimited, Publicly available.
Free-to-read Unrestricted online access
Summary
Platinum Octaethyl Porphyrin (Pt.OEP) is an efficient phosphor under ultraviolet excitation. The phosphorescent triplet state (T(sub 1)) is readily quenched by the oxygen (O2) molecules. This phenomenon is being utilized as the basis for global air pressure measurements in aerodynamic facilities at various laboratories. The exact mechanism by which O2 molecules quench the (T(sub 1) - S(sub 0)) transitions is still unknown. The diamagnetic S(sub n) singlet states, which feed T(sub 1) states via intersystem crossings, would presumably not be affected by O2. It must be the magnetic T(sub 1) states, which can interact with the paramagnetic O2 molecules, that are affected. However, our positron lifetime and Doppler broadening studies suggest the formation of (S(sub n) central dot O2) complexes which can also eventually reduce the population of the T(sub 1) states (i.e. quench phosphorescence). This is possible since higher triplet states in (Pt.OEP) are admixed with the S(sub n) states via spin orbit interactions. The experimental procedures and the results of various measurements are discussed in this paper.
Other Subject(s)
Collection
NASA Technical Reports Server (NTRS) Collection.
Note
Document ID: 19960028542.
Accession ID: 96N29269.
NAS 1.15:111534.
NASA-TM-111534.
Meeting of the Southeastern Section of the American Physical Society; 10-12 Nov. 1994; Newport News, VA; United States.
Terms of Use and Reproduction
No Copyright.
View MARC record | catkey: 15650396