Phosphorescence transients induced by magnetic resonance fast passage

Winscom, C. J.; Maki, August H.

doi:10.1016/0009-2614(71)85061-3

Cited by 130 publications

(64 citation statements)

References 19 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…For that reason, the zero field splitting parameters D and E were determined by optical detection of magnetic resonance (ODMR) in zero field. At 1.5 K the meth· od used was the analysis of phosphorescence transients after a saturating fast passage [37,38). The ODMR apparatus was in prinCiple the same as described by Zuc1ich et al [39).…”

Section: Methodsmentioning

confidence: 99%

Transannular interactions in [2,2] phanes as studied by magnetic resonance and optical spectra

Schweitzer¹,

Colpa²,

Behnke³

et al. 1975

Chemical Physics

View full text Add to dashboard Cite

The interaction of IT-eleetrons in [2.2] phanes was studied both experimcntally and theoretically. The fluorescence and phosphorescence spectra were measured at liquid helium temperature; in addition, the zero field splitting parameters D and E were detcrmined by ODMR in zero field and by ordinary ESR at X·band. The results for the phanes with two identical aromatic units can be summarized as follows: The rather small reduction of the D and E values of the order of 10% with respect to the monomrrs indicates, in agreement with the theoretical treatment given in part II, that the two unpaired electrons of the excited triplet state have a high probability to be at a given time in the same half of the molecule. While the fluorescence spectra show the typical behaViour of emission spectra of dimers or excimers, the phosphorescence spectra CKhibit some remaining structure. This behaviour which indicates a somewhat weaker coupling among the triplet orbitals as compared to the singlet orbitals can also be understood on the basis of theoretical considerations. for a phane with two different aromatic units thl! behaviour is found t~ be more Similar to the corresponding aromatic monomer with the lower ex" cited states with some pcrtu~bation by the other part of the phane also.in agreement with theoretical expectation.

show abstract

Section: Methodsmentioning

confidence: 99%

Transannular interactions in [2,2] phanes as studied by magnetic resonance and optical spectra

Schweitzer¹,

Colpa²,

Behnke³

et al. 1975

Chemical Physics

View full text Add to dashboard Cite

show abstract

“…(1967), a new optical method has become available for detailed studies of the populating and depopulating kinetics of aromatic triplet states Burland and Schmidt, 1971 ;Harris and Hoover, 1971 ;Harris, 1971;Winscom and Maki, 1971). This method is also referred to in the literature as "phosphorescence microwave double resonance" or PMDR (Tinti ef aI., 1969 …”

Section: Introductionmentioning

confidence: 99%

Optically Detected Magnetic Resonance of the Tryptophan Phosphorescent State in Native Proteins*

Zuclich

Schweitzer

Maki

1973

Photochem & Photobiology

View full text Add to dashboard Cite

Abstrad-The phosphorescent triplet state of tryptophan has been studied by the method of optically detected magnetic resonance (ODMR) at pumped helium temperatures in zero magnetic field. Only one of the triplet sublevels is found to be significantly radiative; the other two decay radiationlessly. Although the phosphorescence and ODMR decay lifetimes are influenced by spin-Ianice relaxation processes at T = 1·3°K. the lifetime of the radiative level can be estimated as approximately 2 s. whereas the lifetimes of the non·radiative levels are in excess of 10 s. Comparison of the ODMR signals and the phosphorescence spectra has been made for tryptophans in native proteins with the folJowing results: the ODMR signals of the two types of tryptophan sites in horse liver alcohol dehydrogenase can be resolved due to a shift in the D and E values of the respective triplet states; binding of the substrate tri-N-acetylglucosamine to hen lysozyme leads to a considerable narrowing of the phosphorescence peaks and ODMR signals as well as to a shift in the E value oflhe triplet state.The following tentative conclusions can be reached: the tryptophan triplet D and E values are measurably affected by the environment of the chromophore in the protein, as are the Iinewidths of the magnetic resonance transitions. The I EI value is reduced and the magnetic resonance Iinewidth is increased with increasing exposure of the tryptophan to hydroxylic solvent. Although a considerable part of the width of the magnetic resonance transition can be ascribed to a heterogeneity of environments in the sample, there appears to exist an intrinsic line-broadening process which at present is not understood.

show abstract

“…MIDP experiments [8] did not give signals because strong spin lattice relaxation rates between the triplet sublevels exist. This can be seen from the fact that, at 1·3 K, the decay rate of the fast passage signal [9], under continuous irradiation of light is a factor of Z·3 larger for the ZIEI-transition than for the IDI + lEI-transition (0·58 secl for the IDI + lEI-transition and 1·35 sec-l for the ZIEI-transition). In figure 5 (b) the phosphorescence emission is shown of the same sample after 1Z hours of irradiation with V.V.-light of wavelengths between 3510 and 3610 A ('" 5 mW Argon-Ion-laser).…”

Section: Resultsmentioning

confidence: 88%

Electronic properties of kekulene

Schweitzer¹,

Hausser²,

Vogler³

et al. 1982

Molecular Physics

View full text Add to dashboard Cite

The fluorescence and phosphorescence of kekulene in a host matrix of polycrystalline tetrachlorobenzene are investigated, together with the triplet zero field splitting parameters IDI and lEI obtained by ODMR in zero field. The D value is also calculated within a semi-empirical 1T-theory and compared with experiment. It could be shown that the triplet state energies of a number of different sites of kekulene in the host matrix and the zero field splitting parameters are related, in first order, by spin orbit interaction.

show abstract

Phosphorescence transients induced by magnetic resonance fast passage

Cited by 130 publications

References 19 publications

Transannular interactions in [2,2] phanes as studied by magnetic resonance and optical spectra

Transannular interactions in [2,2] phanes as studied by magnetic resonance and optical spectra

Optically Detected Magnetic Resonance of the Tryptophan Phosphorescent State in Native Proteins*

Electronic properties of kekulene

Contact Info

Product

Resources

About