Magnetic fluorescence and phosphorescence quenching of gas-phase sulfur dioxide

Makarov, Vladimir I.; Лаврик, Н. Л.; Skubnevskaya, G. I.; Bazhin, N. M.

doi:10.1007/bf02064247

Cited by 15 publications

(3 citation statements)

References 6 publications

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“…Evans et al700 were the first to use this method in a quantitative theory of the CIDNP effect. Then the method was adopted by Salikhov et a1.715p717 and by H a b e r k~r n .~~~~~~~ Further contributions are due to Adrian and M o n~h i c k ,~~~~~~~ to S h~s h i n ,~~~~~~~ and to Mints and P~k h o v .~~~ For an illustration of the method we shall outline the procedure used by Haberkorn.682 He used the following form of r-dependent operators in eq 120: &(r) = -4r)Qs (192) K(r) = Itorob(r -ro) (195) p(r, t = 0 ) = Porob(r -ro) (196) Applying Laplace transformation in time and Fourier transformation in space, eq 120 was transformed into a matrix equation that could be formally solved and after Fourier transforming backward yielded the following matrix equation for p(ro):…”

Section: Stainer and Ulrichmentioning

confidence: 99%

Magnetic field effects in chemical kinetics and related phenomena

Steiner¹,

Ulrich²

1989

Chem. Rev.

1,556

1,516

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Section: Stainer and Ulrichmentioning

confidence: 99%

Magnetic field effects in chemical kinetics and related phenomena

Steiner¹,

Ulrich²

1989

Chem. Rev.

1,556

1,516

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“…The intramolecular relaxation process from electronically excited states of polyatomic molecules such as intersystem crossing (ISC), internal conversion, or vibrational redistribution, which is regarded as a primary process of photochemical reactions, is strongly related to level structure and interstate interaction in the excited states. − These processes are expected to be significantly affected if external perturbations which change a level structure are applied to excited molecules. The external magnetic field ( H ) is one such perturbation, and the magnetic quenching of emission resulting from the field-induced change in excitation dynamics has been reported in rather small molecules. − …”

Section: Introductionmentioning

confidence: 99%

“…The external magnetic field (H) is one such perturbation, and the magnetic quenching of emission resulting from the field-induced change in excitation dynamics has been reported in rather small molecules. [6][7][8][9][10][11][12] The level structure of the triplet state isoenergetic with S 1 and the nature and strength of the singlet-triplet (S-T) interaction have been precisely measured in glyoxal or propynal by Lombardi, Huber, and their co-workers [13][14][15][16] with elegant techniques of anticrossing spectroscopy and quantum beat spectroscopy. Ultrahigh-resolution fluorescence excitation spectroscopy both in the absence and in the presence of a magnetic field has also been applied to rather large molecules such as pyrazine or pyrimidine for elucidation of the nature of the S-T interaction by Kommandeur, Majewski, Pratt, and their coworkers.…”

Section: Introductionmentioning

confidence: 99%

Magnetic Field Effects on Fluorescence in Isolated Molecules with the Intermediate Level Structure of Singlet−Triplet Mixed States

Ohta

1996

J. Phys. Chem.

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A review is presented of external magnetic field effects on the fluorescence of isolated molecules which exhibit the intermediate level structure composed of singlet−triplet mixed states. Fluorescence intensity (quantum yield), decay profile (lifetime), and polarization are well affected by an external magnetic field, even when fluorescence is considered to be emitted from a diamagnetic singlet state. Effects of molecular rotation, molecular vibration, methyl internal rotation, and deuterium substitution are observed in magnetic field effects on fluorescence, and these effects are interpreted in terms of the level density of the triplet states coupled to a singlet state. It is also shown how intramolecular vibrational energy redistribution and dissociation via triplet states are related to the field dependence of fluorescence.

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Effect of A Magnetic Field on Photophysical Processes of Molecules

Lin

Hayashi

Kono

et al. 1997

J Chinese Chemical Soc

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A main purpose of this paper is to present a density matrix treatment of the magnetic quenching of molecular luminescence. Unlike the previous theories, which only consider the magnetic effect on the nonradiative rate constant, the present theory describes the time-evolution of the system under the action of a magnetic field. Our theory can treat both the steady state and transient molecular luminescence affected by a magnetic field. 203 INTRODUCfIONMagnetic quenching of molecule fluorescence in the gas phase was lust observed for CS 2 by Matsuzaki and Nagakura.' Since this work, similar magnetic effects have been observed for a number of molecules such as S02, 2 formaldehyde.I" glyoxal'" pyrazine,"!' pyrimidine,12.13 and striazine. 14) To interpret the magnetic effect on radlationless transitions of molecules, some theoretical investigations have been reported.":" The magnetic field effect on fluorescence in isolated molecules has recently been reviewed by Ohla.'s Magnetic quenching of fluorescence implies that the nonradiative decay in the singlet excited state is accelerated by a magnetic field. This magnetic field acceleration of nonradiativc decay arises from a field-induced change in level mixing between the initially prepared level and the dark manifold of the neighboring levels by the Zeeman interaction. Two mechanisms have been proposed. According to the direct mechanism, which originates from non-diagonal matrix elements of the Zeeman term between singlet states, the internal conversion is accelerated by the field-induceddirect coupling between the two different electronic states. According to the indirect mechansim, which arises from non-diagonal matrix elements of the Zeeman term among the spin sublevels in a triplet state, the intersystem crossing rate from the prepared singlet level to the triplet manifold is increased by such a coupling.In this paper, we apply the density matrix method to study the dynamics of the system in the presence of a magnetic field. We shall carefully examine the nature of the short-time decay and the long-time decay. Our theoretical treatment takes into account both direct and indirect mechanisms of magnetic quenching; it can also treat both the steady state and transient molecular luminescence affected by a magnetic field. We shall also study the effect of a magnetic field on single-rovibronic-level rate constants of radiationless transitions. THEORYThe time-resolved properties of a molecular system are best described in a zeroth-order representation essentially determined by experimental excitation and detection conditions." One thus introduces a model where a clear distinction is made between the optically bright states which can be initially prepared by impulsive excitation and tl\e reo maining dark states. These states are not cigenstates of the true molecular Hamiltonian Ii and are mixed by the intramolecular interaction tr and the Zeeman interaction fr z (if an external magnetic field exists). The resulting excitation energy exchanges between the bright and dark man...

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Magnetic fluorescence and phosphorescence quenching of gas-phase sulfur dioxide

Cited by 15 publications

References 6 publications

Magnetic field effects in chemical kinetics and related phenomena

Magnetic field effects in chemical kinetics and related phenomena

Magnetic Field Effects on Fluorescence in Isolated Molecules with the Intermediate Level Structure of Singlet−Triplet Mixed States

Effect of A Magnetic Field on Photophysical Processes of Molecules

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