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The influence of temperature on C153 steady-state absorption and fluorescence kinetics in hydrogen bonding solvents.

Dobek K, Karolczak J - J Fluoresc (2012)

Bottom Line: It leads to a modulation of the fluorescence transition dipole moment and it is the primary source of the experimental effects observed.Additionally, we have found that proticity of the solvent induces a rise in the fluorescence transition dipole moment, which leads to a shortening of the fluorescence lifetime.We show that while such bonds do not affect the transition probability, they do change the S(0) an S(1) energy gap which in turn implies a change in non-radiative transition rate in a similar way as in protic solvents, as well as in the fluorescence spectrum position.

View Article: PubMed Central - PubMed

Affiliation: Faculty of Physics, Adam Mickiewicz University, Poznań, Poland. dobas@amu.edu.pl

ABSTRACT
In a recent paper (J Fluoresc (2011) 21:1547-1557) a temperature induced modulation of Coumarin 153 (C153) fluorescence lifetime and quantum yield for the probe dissolved in the polar, nonspecifically interacting 1-chloropropane was reported. This modulation was also observed in temperature dependencies of the radiative and nonradiative rates. Here, we show that the modulation is also observed in another 1-chloroalkane-1-chlorohexane, as well as in hydrogen bonding propionitrile, ethanol and trifluoroethanol. Change in the equilibrium distance between S (0) an S (1) potential energies surfaces was identified as the source of this modulation. This change is driven by temperature changes. It leads to a modulation of the fluorescence transition dipole moment and it is the primary source of the experimental effects observed. Additionally, we have found that proticity of the solvent induces a rise in the fluorescence transition dipole moment, which leads to a shortening of the fluorescence lifetime. Hydrogen bonds are formed by C153 also with hydrogen accepting solvents like propionitrile. We show that while such bonds do not affect the transition probability, they do change the S(0) an S(1) energy gap which in turn implies a change in non-radiative transition rate in a similar way as in protic solvents, as well as in the fluorescence spectrum position. Finally, the influence of temperature on the energies of hydrogen bonds formed by C153 when acting as hydrogen donor or acceptor is reported.

No MeSH data available.


Temperature dependencies of the fluorescence quantum yield, ϕF, of C153 in ClH (a), PPN (b), EtOH (c) and TFEtOH (d)
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Fig4: Temperature dependencies of the fluorescence quantum yield, ϕF, of C153 in ClH (a), PPN (b), EtOH (c) and TFEtOH (d)

Mentions: Using quinine sulphate in 0.05 M H2SO4 (ϕF = 0.52) as a standard, C153 fluorescence quantum yield, ϕF, in all solvents was determined at room temperature. Then, by assuming the room temperature emission spectrum in selected solvent as a standard, temperature dependencies of ϕF were determined, shown in Fig. 4.Fig. 4


The influence of temperature on C153 steady-state absorption and fluorescence kinetics in hydrogen bonding solvents.

Dobek K, Karolczak J - J Fluoresc (2012)

Temperature dependencies of the fluorescence quantum yield, ϕF, of C153 in ClH (a), PPN (b), EtOH (c) and TFEtOH (d)
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3473193&req=5

Fig4: Temperature dependencies of the fluorescence quantum yield, ϕF, of C153 in ClH (a), PPN (b), EtOH (c) and TFEtOH (d)
Mentions: Using quinine sulphate in 0.05 M H2SO4 (ϕF = 0.52) as a standard, C153 fluorescence quantum yield, ϕF, in all solvents was determined at room temperature. Then, by assuming the room temperature emission spectrum in selected solvent as a standard, temperature dependencies of ϕF were determined, shown in Fig. 4.Fig. 4

Bottom Line: It leads to a modulation of the fluorescence transition dipole moment and it is the primary source of the experimental effects observed.Additionally, we have found that proticity of the solvent induces a rise in the fluorescence transition dipole moment, which leads to a shortening of the fluorescence lifetime.We show that while such bonds do not affect the transition probability, they do change the S(0) an S(1) energy gap which in turn implies a change in non-radiative transition rate in a similar way as in protic solvents, as well as in the fluorescence spectrum position.

View Article: PubMed Central - PubMed

Affiliation: Faculty of Physics, Adam Mickiewicz University, Poznań, Poland. dobas@amu.edu.pl

ABSTRACT
In a recent paper (J Fluoresc (2011) 21:1547-1557) a temperature induced modulation of Coumarin 153 (C153) fluorescence lifetime and quantum yield for the probe dissolved in the polar, nonspecifically interacting 1-chloropropane was reported. This modulation was also observed in temperature dependencies of the radiative and nonradiative rates. Here, we show that the modulation is also observed in another 1-chloroalkane-1-chlorohexane, as well as in hydrogen bonding propionitrile, ethanol and trifluoroethanol. Change in the equilibrium distance between S (0) an S (1) potential energies surfaces was identified as the source of this modulation. This change is driven by temperature changes. It leads to a modulation of the fluorescence transition dipole moment and it is the primary source of the experimental effects observed. Additionally, we have found that proticity of the solvent induces a rise in the fluorescence transition dipole moment, which leads to a shortening of the fluorescence lifetime. Hydrogen bonds are formed by C153 also with hydrogen accepting solvents like propionitrile. We show that while such bonds do not affect the transition probability, they do change the S(0) an S(1) energy gap which in turn implies a change in non-radiative transition rate in a similar way as in protic solvents, as well as in the fluorescence spectrum position. Finally, the influence of temperature on the energies of hydrogen bonds formed by C153 when acting as hydrogen donor or acceptor is reported.

No MeSH data available.