Formation of 1:1 and 1:2 exciplexes between excited mercury atom and amines in the liquid phase

Abstract

The liquid-phase mercury-photosensitized luminescence of amines has been investigated by a steady-state illumination method over a wide range of concentration of amines at several temperatures. The emission band from an exciplex (HgA*) between an excited mercury atom and an amine molecule was observed at ca. 370 nm in cyclohexane. A new band appeared with diethylamine, dipropylamine, di-2-propylamine and dibutylamine at high concentrations on the long-wavelength side of the band of HgA*, while two new bands appeared for propylamine, butylamine and tert-butylamine at high concentrations. The intensities of the bands observed at high concentrations increased with increasing concentration of the amines. These bands were assigned to two kinds of 1:2 exciplexes (HgA₂^* and HgA₂^**). The enthalpy changes among these exciplexes were estimated from the temperature dependences of the intensity ratios of the emission bands.

References

1. L. F. Phillips, Acc. Chem. Res., 1974, 7, 135.
2. A. B. Callear, Chem. Rev., 1987, 87, 355.
3. R. R. Kuntz and G. J. Mains, J. Am. Chem. Soc., 1963, 85, 2219.
4. S. Yamamoto and M. Doi, J. Chem. Soc., Faraday Trans., 1997, 93, 1309.
5. I. B. Berlman, Handbook of Fluorescence Spectra of Aromatic Molecules, Academic Press, London, 1965.
6. M. K. Phibbs and B. de B. Darwent, J. Chem. Phys., 1950, 18, 679.
7. A. B. Callear, D. R. Kendall and L. Krause, Chem. Phys., 1978, 29, 415.
8. A. B. Callear and C. P. Devonport, J. Chem. Phys., 1983, 78, 3738.
9. R. H. Newman, C. G. Freeman, M. J. McEwan, R. F. C. Claridge and L. F. Phillips, Trans. Faraday Soc., 1971, 67, 1360.