RECENT STUDIES ON TRIPLET-SINGLET TRANSITIONS IN AROMATIC MOLECULES

Abstract

The paper is divided into four parts. The first part discusses the selection rules of the intersystem crossing process in systems having both n, pi(*) and pi,pi(*) types of states. The detection of the polarized state by observing the phosphorescence emission requires that the radiative lifetime of the latter from at least one of the three sublevels of the lowest triplet state be shorter than the characteristic time for the spin-lattice relaxation processes between the three sublevels of the triplet state. This is demonstrated to be the case for pyrazine in its n,pi(*) triplet state at low temperatures (1.6 -10K) and discussed in Section III. In the third part of the paper, a summary of the theory of the triplet-singlet radiative transitions is given. A comparison of phosphorescence properties of the different systems is made and the observed differences are explained in the framework of the present theory. In the last part of this paper, the important experiments needed in this field are recommended.

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Document Details

Document Type
Technical Report
Publication Date
Jul 01, 1968
Accession Number
AD0679191

Entities

People

  • Mostafa El-Sayed

Organizations

  • University of California, Los Angeles

Tags

Communities of Interest

  • Materials and Manufacturing Processes

DTIC Thesaurus Topics

  • Aromatic Compounds
  • Aromatic Hydrocarbons
  • Chemical Synthesis
  • Chemistry
  • Crystal Structure
  • Cyclic Hydrocarbons
  • Hydrocarbons
  • Internal Conversion
  • Low Temperature
  • Naphthalenes
  • Organic Chemistry
  • Polarization
  • Probability
  • Quantum Properties
  • Quantum Yields
  • Relaxation Time
  • Spin-Orbit Interaction

Readers

  • Molecular Photonics/Laser Physics
  • Theoretical Analysis.