Journal ArticleDOI
The lowest triplet state of free base porphin
TLDR
In this paper, an appropriate mathematical model for describing the fluorescence transients is introduced in conjunction with a specific series of experiments from which one may evaluate the molecular quantities in a systematic way.Abstract:
Transient signals in the fluorescence intensity induced by microwaves can be used to acquire quantitative information on the molecular rates of populating and depopulating of the lowest triplet state of organic molecules. This method seems especially promising when the molecule emits no detectable phosphorescence. Part of this paper concerns the introduction of an appropriate mathematical model for describing the fluorescence transients. The model is formulated in conjunction with a specific series of experiments from which one may evaluate the molecular quantities in a systematic way. The kinetics of the lowest triplet state of free base porphin (H2P) are determined explicitly by this method. In the discussion the results for H2P are compared with those for Zn porphin. A satisfactory qualitative explanation based on the theory of radiationless transitions can be given for the great difference in behaviour of these two porphyrin molecules. Short attention is given to effects due to the photochemical shift...read more
Citations
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Journal ArticleDOI
Principles of phosphorescent organic light emitting devices.
TL;DR: This review highlights the basic principles and the main mechanisms behind phosphorescent light emission of various classes of photofunctional OLED materials, like organic polymers and oligomers, electron and hole transport molecules, elementoorganic complexes with heavy metal central ions, and clarify connections between the main features of electronic structure and the photo-physical properties of the phosphorescent OLED materials.
Journal ArticleDOI
Theory and Calculation of the Phosphorescence Phenomenon
TL;DR: The theory and principles of computational phosphorescence are illustrated by highlighting studies of classical examples like molecular nitrogen and oxygen, benzene, naphthalene and their azaderivatives, porphyrins, as well as by reviewing current research on systems like electrophosphorescent transition metal complexes, nucleobases, and amino acids.
Journal ArticleDOI
Synthesis, Spectroscopy, and Molecular Orbital Calculations of Subazaporphyrins, Subphthalocyanines, Subnaphthalocyanines, and Compounds Derived Therefrom by Ring Expansion1
TL;DR: A number of unsymmetrical Pc's and Nc's have been synthesized in moderate yields by the ring expansion reaction of structurally distorted subphyrin derivatives with isoindolediimine derivatives in dimethyl sulfoxide−chloronaphthalene (or chlorobenzenes or aromatic hydrocarbons such as toluene and xylene) mixtures as mentioned in this paper.
Journal ArticleDOI
Homogeneous linewidth of the S1←S0 transition of free‐base porphyrin in an n‐octane crystal as studied by photochemical hole‐burning
TL;DR: In this paper, the homogeneous linewidth of the 0-0 band of the S1←S0 transition of freebase porphyrin (H2P) in an n-octane matrix and its temperature dependence (T=1.5-4.2 K) have been measured by means of photochemical hole-burning.
Journal ArticleDOI
The chlorophyll triplet state as a probe of structure and function in photosynthesis.
TL;DR: This review has tried to emphasize work on the triplet state of chlorophyll in photosynthetic and related systems which has appeared since previous reviews were published, and to demonstrate the impact that the newly available crystal structure has had on many of these studies.
References
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Journal ArticleDOI
The energy gap law for radiationless transitions in large molecules
Robert Englman,Joshua Jortner +1 more
TL;DR: In this article, a unified treatment of non-radiative decay processes in large molecules which involve either electronic relaxation between two electronic states or unimolecular rearrangeme(s) is presented.
Journal ArticleDOI
Spectra of porphyrins
TL;DR: In this article, the absorption spectra of metal porphyrins derived from the basic skeleton are discussed in terms of a four-orbit model, that is intensity changes and energy shifts are related to the properties of two top filled and two lowest empty pi orbitals.
Journal ArticleDOI
Theory of Electronic Energy Relaxation in the Solid Phase
G. W. Robinson,R. P. Frosch +1 more
TL;DR: In this article, a theory of electronic energy relaxation in the solid phase is presented and the physical limit where the electronic transition is slow compared with vibrational relaxation is shown to be a well-defined mathematical limit in the theory.
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