Photoinduced Electron Transfer and Intramolecular Folding in a Tricarbonylrhenium (Bi)pyridine Based Donor/Crown/Acceptor Assembly: Dependence on Solvent

Inorganic Chemistry

Volumn 35, Issue 7, 1996, Pages 2032-2035

  Berg Brennan, Christine A ^a   Yoon, Dong I ^a   Slone, Robert V ^a   Kazala, Amy P ^a   Hupp, Joseph T ^a  

^a NORTHWESTERN UNIVERSITY   (United States)

Author keywords

[No Author keywords available]

Indexed keywords

EID: 0000640122     PISSN: 00201669     EISSN: None     Source Type: Journal    
DOI: 10.1021/ic950534e     Document Type: Article

References (13)

1. Yoon, D. I.; Berg-Brennan, C. A.; Lu, H.; Hupp, J. T. Inorg. Chem. 1992, 31, 3192.
2. Berg-Brennan, C. A.; Yoon, D. I.; Hupp, J. T. J Am. Chem. Soc. 1993, 115, 2048.
3. obs, vs. 1/T parameters to avoid confusion with the asterisk notation for electronic excited states (cf. Scheme 1).
4. Six of the eight solvents yield plots that clearly display two activation regimes and a well-defined transition temperature (cf. Figure 1). Methyl benzoate and dichloropropane, however, yield plots that are nonlinear, but less obviously dual component - at least over the accessible temperature ranges. Nevertheless, for completeness, we have assumed that the observed curved Arrhenius plots are dual-component plots and have reported best fit parameters (Table 1). Clearly, however, the parameters should be regarded as much less certain than those reported for other solvents
5. Cross-coupling to protons g apparently also occurs, but phase-matching problems prevented us from establishing the interaction with certainty.
6. (a) Smithrud, D. B.; Sanford, I C.; Ferguson, S. B.; Carcanague, D. R.; Evanseck, J. D.; Houk, K. N.; Diederich, F. Pure Appl. Chem. 1990, 62, 2227.
7. (b) Diederich, F.; Smithrud, D. B., Sanford, E. M.; Wyman, T. B.; Ferguson, S. B.; Carcanague, D R.; Chao, I.; Houk, K. N. Acta Chem. Scand 1992, 46, 205.
8. (c)Smithrud, D. B.; Wyman, T. B.; Diederich, F. J. Am. Chem. Soc. 1991, 113, 5420.
9. Reichardt, C. Solvents and Solvent Effects in Organic Chemistry, 2nd ed ; VCH: Weinheim, Germany, 1988.
10. tr were the same for all solvents.) Krug et al. ( Nature 1976, 267, 566; J. Phys. Chem. 1976, 80, 2235, 2341) have pointed out that apparent enthalpy/entropy correlations can readily arise from a correlated propagation of experimental errors. They argue that free energy vs enthalpy correlations, at an average experimental temperature, offer a means for assessing the chemical validity of enthalpy/ entropy correlations (since experimental errors for the former should be statistically uncorrelated). The data in Table 2 fail this test (r = 0.28), indicating that the correlations are likely spurious.
11. tr were the same for all solvents.) Krug et al. ( Nature 1976, 267, 566; J. Phys. Chem. 1976, 80, 2235, 2341) have pointed out that apparent enthalpy/entropy correlations can readily arise from a correlated propagation of experimental errors. They argue that free energy vs enthalpy correlations, at an average experimental temperature, offer a means for assessing the chemical validity of enthalpy/ entropy correlations (since experimental errors for the former should be statistically uncorrelated). The data in Table 2 fail this test (r = 0.28), indicating that the correlations are likely spurious.
12. A reviewer has pointed out that if the Coulombic exlanation is correct, the excited-state folding equilibrium could likely be altered by derivatizing the bipyridyl ligand so as to yield a ligand-localized π - π*state, in place of the charge transfer state, as the lowest-lying excited state.
13. Blackbourn, R. L.; Hupp, J. T. J. Phys. Chem. 1993, 97, 3278.