Primary photophysical processes of discrete pseudotetrahedral oxovanadium centers dispersed in a silica xerogel matrix

Inorganica Chimica Acta

Volumn 243, Issue 1-2, 1996, Pages 185-191

  Tran, Kim ^a   Stiegman, A E ^b   Scott, Gary W ^a  

^a UNIVERSITY OF CALIFORNIA   (United States)

^b FLORIDA STATE UNIVERSITY   (United States)

Author keywords

Oxovanadium; Photophysics; Silica xerogel matrix

Indexed keywords

ACTIVATION ENERGY; CHROMOPHORES; PHOTOPHYSICS; QUANTUM THEORY; QUANTUM YIELD; SILICA; SILICA GEL; TEMPERATURE DISTRIBUTION; VANADIUM COMPOUNDS; XEROGELS;

INTER-SYSTEM CROSSINGS; LOW FREQUENCY REGIONS; OXOVANADIUM; PHOSPHORESCENCE LIFETIME; PHOTOPHYSICAL PROPERTIES; SILICA XEROGEL; TEMPERATURE DEPENDENCE; TIME RESOLVED TECHNIQUE;

EXCITED STATES;

EID: 0011561003     PISSN: 00201693     EISSN: None     Source Type: Journal    
DOI: 10.1016/0020-1693(95)04906-1     Document Type: Article

References (38)

1. (a) S.T. Oyama, Res. Chem. Int., 15 (1991) 165.
2. (b) G.C. Bond and S.F. Tahir, Appl. Catal., 71 (1991) 1.
3. (a) S.L. Kaliaguine, B.N. Shelimov and V.B. Kazansky, J. Catal., 55 (1978) 384.
4. (b) T. Tanaka, S. Takenaka, T. Funabiki and S. Yoshida, Chem. Lett., (1994) 1585.
5. (a) S. Yoshida, Y. Magatani, S. Noda and T. Funabiki, J. Chem. Soc. Chem. Commun., (1981) 601.
6. (b) S. Yoshida, T. Tanaka, M. Okada and T. Funabiki, J. Chem. Soc. Faraday Trans., 80 (1984) 119.
7. (c) T. Tanaka, Y. Nishimura, S. Kawasaki, M. Ooe, T. Funabiki and S.J. Yoshida, Catalysis, 118 (1989) 327.
8. M. Anpo, I. Tanahashi and J. Kubokawa, J. Phys. Chem., 84 (1980) 3440
9. M. Anpo, M. Sunamoto and M. Che, J. Phys. Chem., 93 (1989) 1187.
10. (a) A.E. Stiegman, H. Eckert, G. Plett, M. Anderson and A. Yavrouian, Chem. Mater., 5 (1993) 1592.
11. (b) S.W. Aliwi, J. Photochem. Photobiol. A, 44 (1988) 179.
12. (a) S.T. Oyama, G.T. Went, K.B. Lewis, A.T. Bell and G.A Somorjai, J. Phys. Chem., 93 (1989) 6786.
13. (b) H. Eckert and I.E. Wachs, J. Phys. Chem., 93 (1989) 6796.
14. (c) G.T. Went, S.T. Oyama and A.T. Bell, J. Phys. Chem., 94 (1990) 4240.
15. (d) M. Schrami-Marth, A. Wokaun, M. Pohl and H.-L. Krauss, J. Chem. Soc. Faraday Trans., 87 (1991) 2635.
16. (e) G. Deo and I.E. Wachs, J. Catal., 129 (1991) 307.
17. (f) N. Das, H. Eckert, H. Hu, I.E. Wachs, J.F. Walzer and J.F. Feher, J. Phys. Chem., 97 (1993) 8240.
18. K. Tran, M.A. Hanning-Lee, A. Biswas, A.E. Stiegman and G.W. Scott, J. Am. Chem. Soc., 117 (1995) 2618.
19. (a) M.S. Wrighton, D.S. Ginley and D.L. Morse, J. Phys. Chem., 78 (1974) 2229.
20. (b) D.B. O'Connor, G.W. Scott, D.R. Coulter and A. Yavrouian, J. Phys. Chem., 95 (1991) 10252.
21. -1, which place the singlet into the observed absorption curve, appear reasonable.
22. N.J. Turro, Modern Molecular Photochemistry, Benjamin Cummings, Menlo Park, CA, 1978.
23. N. Mataga and T. Kubota, Molecular Interactions and Electronic Spectra, Marcel Dekker, New York, 1970, pp. 148.
24. N. Mataga, M. Tomura and H. Nishimura, Mol. Phys., 9 (1967) 367.
25. G.W. Robinson and R.P. Frosch, J. Chem. Phys., 37 (1962) 1962.
26. S.H. Lin and R. Bersohn, J. Chem. Phys., 48 (1968) 2732.
27. (a) K. Freed, Top. Curr. Chem., 31 (1972) 105.
28. (b) K. Freed, Acc. Chem. Res., 11 (1978) 74.
29. J. Jortner, S.A. Rice and R.M. Hochstrasser, Adv. Photochem., 7 (1969) 149.
30. M. Lax, J. Chem. Phys., 20 (1952) 1752.
31. Analysis of the non-radiative decay of transition metal complexes in glassy solvents as a function of temperature have reported previously. The majority of compounds investigated have been complexes of 2nd and 3rd row late transition metals (many of them polypyridyl complexes) where the 'activation' energies determined have been assigned to energy gaps between thermally populated spin-orbit states each of which non-radiatively decay at a different rate. For most of these compounds there is strong spectroscopic evidence (e.g. highly temperature dependent emission spectra) and theoretical analysis to support the presence of these states and recommend such an interpretation of the temperature dependent data, (a) D.R. Striplin, G.A. Crosby, J. Phys. Chem., 99 (1995) 7977.
32. (b) G.D. Hager and G.A. Crosby, J. Am. Chem. Soc., 97 (1975) 7031.
33. (c) G.D. Hager, R.J. Watts and G.A. Crosby, J. Am. Chem. Soc., 97 (1975) 7037.
34. (c) K.W. Hipps and G.A. Crosby, J. Am. Chem. Soc., 97 (1975) 7042.
35. (d) S.R. Allsopp, A. Cox, T.J. Kemp, W.J. Reed, V. Carassiti and O. Traverso, J. Chem. Soc. Faraday Trans. I, (1978) 353.
36. -1 determined for the activation energy from the temperature-dependent lifetimes. In addition, the emission and absorption spectra show no anomalous behavior over the temperature range probed. We therefore ascribe the temperature dependence at T < 200 K to a vibronically induced deactivation process and not to thermally populated spin-orbit states. This discussion does, however, raise serious questions as to the contribution thermally populated spin-orbit states and vibronically induced deactivation processes each make to the measured temperature dependence of non-radiative decay in other transition metal complexes.
37. G.F. Imbusch, in B. Di Bartolo (ed.), Advances in Nonradiative Processes in Solids, Nato ASI Series B, Vol 249, Plenum, New York, 1991, pp. 261.
38. H. Selig and H.H. Claassen, J Chem. Phys., 44 (1966) 1404.