Abstract
Time-resolved electron paramagnetic resonance (TREPR) spectra are presented for a phenanthrene-linked copper(II)-free-base porphyrin dimer. In the lowest electronic excited state, the free-base half is in the (π, π*) triplet state and the copper-porphyrin half is in the doublet ground state due to the copper(II) spin. Because of the interaction between the triplet and doublet spins, the excited state of the dimer is described as a coupled triplet-doublet pair state. By choosing the excitation wavelength, this coupled state is produced via either the intersystem crossing within the free base or the energy transfer from the excited state of the copper porphyrin. The observed TREPR spectra show very large spectral widths compared to that of the triplet state in the free-base monomer. In addition, there is a prominent absorptive band in the center of the spectra regardless of the generation pathway. These features can be interpreted as characteristic properties in an intermediate-coupling case, where the degree of the triplet and doublet mixing largely depends on the molecular orientation relative to the magnetic field.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Stehlik D., Möbius K.: Annu. Rev. Phys. Chem.48, 745 (1997)
Blättler C., Jent F., Paul H.: Chem. Phys. Lett.166, 375 (1990)
Kawai K., Okutsu T., Obi K.: J. Phys. Chem.95, 9130 (1991)
Kawai K., Obi K.: Res. Chem. Intermed.19, 865 (1993)
Corvaja C., Maggini M., Prato M., Scorrano G., Venzin M.: J. Am. Chem. Soc.117, 8857 (1995)
Ishii K., Fujisawa J., Ohba Y., Yamauchi S.: J. Am. Chem. Soc.118, 13079 (1996)
Fujisawa J., Ishii K., Ohba Y., Yamauchi S., Fuhs M., Möbius K.: J. Phys. Chem. A103, 5869 (1997)
Fujisawa J., Ishii K., Ohba Y., Yamauchi S., Fuhs M., Möbius K.: J. Phys. Chem. A101, 213 (1999)
Mizuochi N., Ohba Y., Yamauchi S.: J. Phys. Chem. A101, 5966 (1997)
Ishii K., Hirose Y., Kobayashi N.: J. Am. Chem. Soc.120, 10551 (1998)
Mizuochi N., Ohba Y., Yamauchi S.: J. Phys. Chem. A103, 7749 (1999)
Conti F., Corvaja C., Toffoletti A., Mizuochi N., Ohba Y., Yamauchi S., Maggini M.: J. Phys. Chem. A104, 4962 (2000)
Teki Y., Miyamoto S., Iimura K., Nakatsuji M., Miura Y.: J. Am. Chem. Soc.122, 984 (2000)
Asano-Someda M., van der Est A., Krüger U., Stehlik D., Kaizu Y., Levanon H.: J. Phys. Chem. A103, 6704–6714 (1999)
van der Est A., Asano-Someda M., Ragogna P., Kaizu Y.: J. Phys. Chem. A106, 8531 (2002)
Asano-Someda M., Ichino T., Kaizu Y.: J. Phys. Chem. A101, 4484–4490 (1997)
Toyama N., Asano-Someda M., Ichino T., Kaizu Y.: J. Phys. Chem. A104, 4857 (2000)
Asano-Someda M., Kaizu Y.: Inorg. Chem.38, 2303–2311 (1999)
Asano-Someda M., Jinmon A., Toyama N., Kaizu Y.: Inorg. Chim. Acta324, 347–351 (2001)
Jaegermann P., Plato M., von Maltzan B., Möbius K.: Mol. Phys.78, 1057–1074 (1993)
Asano-Someda M., Toyama N., Kaizu Y.: Mol. Cryst. Liq. Cryst.379, 165–170 (2002)
Toyama N., Asano-Someda M., Kaizu Y.: Mol. Phys. (in press)
Bencini A., Gatteschi D.: Electron Paramagnetic Resonance of Exchange Coupled Systems, p. 48. Berlin: Springer 1990.
Ishii K., Kobayashi N.: Coord. Chem. Rev.198, 231 (2000)
van Dorp W.G., Canters G.W., van der Waals J.H.: Chem. Phys. Lett.35, 450 (1975)
van der Poel W.A.J.A., Nuijs A.M., van der Waals J.H.: J. Phys. Chem.90, 1537 (1986)
Ake R.L., Gouterman M.: Theor. Chim. Acta15, 20 (1969)
Kooter J.A., Canters G.W., van der Waals J.H.: Mol. Phys.33, 1545 (1977)
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Asano-Someda, M., Toyama, N. & Kaizu, Y. Time-resolved EPR spectra of a photoexcited phenanthrene-linked copper(II)-free-base porphyrin dimer: An intermediate-coupling case in a triplet-doublet spin system. Appl. Magn. Reson. 23, 393–407 (2003). https://doi.org/10.1007/BF03166629
Received:
Revised:
Issue Date:
DOI: https://doi.org/10.1007/BF03166629