Abstract
A matrix of trans-1-(2-naphthyl)-1-phenylethene (t-NPE) fluorescence spectra obtained from benzene solutions at 20 °C by varying the excitation wavelength (λexc) and the oxygen concentration is resolved into pure conformer fluorescence spectra by use of principal component analysis with self-modeling based on optimum global Stern-Volmer constant criteria. The resulting fractional contributions of the two components to the fluorescence spectra are combined with observed fluorescence quantum yields as a function of λexc to obtain the conformer-specific quantum yields. These quantum yields and fluorescence lifetimes are used to determine conformer-specific radiative and radiationless rate constants. Comparison with results from an analogous study in methylcyclohexane reveals pronounced, differential enhancements of all these rate constants in benzene (Bz). Preliminary measurements of emission from a cis-1-(2-naphthyl)-1-phenylethene (c-NPE) solution in Bz at 20 °C, under static cell conditions, are dominated by sequential two-photon-induced t-NPE fluorescence due to excitation of t-NPE formed photochemically from the cis isomer. The spectra also reveal a weak structureless broad emission, which is assigned to 1c-NPE* by comparison with the published low temperature fluorescence spectrum of c-NPE in a hydrocarbon glass. The conformational origin of this emission is addressed.
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For key references, see: a Yu. B. Sheck, N. P. Kovalenko, M. V. Alfimov, Conformeric fluorescence and phosphorescence of aromatic-molecules with a possibility of rotation of chromophoric fragments around single chemical bonds, J. Lumin., 1977, 15, 157–168.
E. Haas, G. Fischer and E. Fischer, Conformational equilibriums in 1,2-diarylethylenes manifested in their emission spectra and lifetimes, J. Phys. Chem., 1978, 82, 1638–1643.
J. B. Birks, G. Bartocci, G. G. Aloisi, S. Dellonte and F. Barigelletti, Fluorescence analysis of trans-2-styrylnaphthalene in solution, Chem. Phys., 1980, 51, 113–120.
For reviews, see: a E. Fischer, Emission spectroscopy evidence for the existence of rotamers in solutions of trans-diarylethylenes and related compounds, J. Photochem., 1981, 17, 331–340.
U. Mazzucato and F. Momicchioli, Rotational isomerism in trans-1,2-diarylethylenes, Chem. Rev., 1991, 91, 1679–1719.
E. Havinga and J. L. M. A. Schlatmann, Remarks on the specificities of the photochemical and thermal transformations in the vitamin D field, Tetrahedron, 1961, 16, 146–152.
E. Havinga, Über einige photochemische reactionen, Chimia, 1962, 16, 145
H. J. C. Jacobs and E. Havinga, Photochemistry of vitamin D and its isomers and of simple trienes, Adv. Photochem., 1979, 11, 305–373.
J. Saltiel, D. F. Sears, Jr., J.-O. Choi, Y.-P. Sun and D. W. Eaker, The fluorescence, fluorescence-excitation and UV absorption spectra of trans-1-(2-naphthyl)-2-phenylethene conformers, J. Phys. Chem., 1994, 98, 35–46.
J. Saltiel, N. Tarkalanov and D. F. Sears, Jr., Conformer specific adiabatic cis to trans photoisomerization of cis-1-(2-naphthyl)-2-phenylethene. A striking application of the NEER principle, J. Am. Chem. Soc., 1995, 117, 5586–5587.
J. Saltiel, A. S. Waller and D. F. Sears, Jr., The temperature and medium dependencies of cis-stilbene fluorescence. The energetics for twisting in the lowest excited singlet state, J. Am. Chem. Soc., 1993, 115, 2453–2465.
J. Saltiel, Y. Zhang, D. F. Sears, Jr., and J.-O. Choi, Fluorescence, fluorescence-excitation and absorption spectra of trans-1-(2-anthryl)-2-phenylethene conformers, Res. Chem. Intermed., 1995, 21, 899–921.
J. Saltiel, Y. Zhang and D. F. Sears, Jr., Highly efficient conformer-specific adiabatic cis - trans photoisomerization of cis-1-(2-anthryl)-2-phenylethene in S1, J. Am. Chem. Soc., 1996, 118, 2811–2817.
J. Saltiel, Y. Zhang and D. F. Sears, Jr., Temperature dependence of the photoisomerization of cis-1-(2-anthryl)-2-phenylethene. Conformer-specificity, torsional energetics and mechanism, J. Am. Chem. Soc., 1997, 119, 11202–11210.
W. H. Melhuish, A standard fluorescence spectrum for calibrating spectro-fluorophotometers, J. Phys. Chem., 1960, 64, 762–764.
J. N. Demas and G. A. Crosby, The measurement of photoluminescence quantum yields. A review, J. Phys. Chem., 1971, 75, 991–1024.
S. R. Meech and D. Phillips, Photophysics of some common fluorescence standards, J. Photochem., 1983, 23, 193–217.
J. Saltiel and B. W. Atwater, Spin-statistical factors on diffusion-controlled reactions, Adv. Photochem., 1988, 14, 1–90.
H. Görner, D. W. Eaker and J. Saltiel, Analysis of the decay of 1-phenyl-2-(2-naphthyl)ethene triplets. A nanosecond pulsed laser study, J. Am. Chem. Soc., 1981, 103, 7164–7169.
G. G. Aloisi, F. Elisei, L. Latterini, U. Mazzucato and M. A. J. Rodgers, Excited state behavior of diarylethenes in the subnanosecond timescale: The role of an upper singlet, J. Am. Chem. Soc., 1996, 118, 10879–10887.
G. Bartocci, F. Masetti, U. Mazzucato and G. Marconi, Photoisomerization mechanism and conformational equilibria of styrylnaphthalenes–A study based on photophysical properties and molecular-orbital calculations, J. Chem. Soc., Faraday Trans. 2, 1984, 80, 1093–1105.
M. Sumitani, S. Nagakura and K. Yoshihara, Laser-photolysis study of trans→cis photoisomerization of trans-1-phenyl-2-(2-naphthyl)ethylene, Chem. Phys. Lett., 1974, 29, 410–413.
S. A. Krysanov and M. V. Alfimov, Picosecond spectroscopy of phenylnaphthylethylenes, Chem. Phys. Lett., 1983, 98, 176–178.
J. Saltiel and D. W. Eaker, Lifetime and geometry of 1-phenyl-2-(2-naphthyl)ethene triplets. Evidence against the triplet mechanism for direct photoisomerization, Chem. Phys. Lett., 1980, 75, 209–213.
G. S. Hammond, S. C. Shim and S. P. Van, Mechanisms of photochemical reactions in solution. LIX. Photoisomerization of β-styrylnaphthalene, Mol. Photochem., 1969, 1, 89–106.
G. Wettermark, L. Tegnér O. Mårtensson, The electronic spectra of stilbene and its naphthyl analogues, Ark. Kemi, 1969, 30, 185–212.
L. Baraldi, F. Momicchioli and G. Ponterini, Conformations and barriers to internal rotation in trans-diarylethylenes: Theoretical investigation using a new INDO-type method (C-INDO), J. Mol. Struct. (THEOCHEM), 1984, 110, 187–202.
G. Bartocci, U. Mazzucato, A. Spalletti, G. Orlandi and G. Poggi, Effect of the nature of the aromatic groups on the lowest excited states of trans-1,2-diarylethenes, J. Chem. Soc., Faraday Trans., 1992, 88, 3139–3144.
J. Saltiel and Y.-P. Sun, Cis-trans isomerization of C,C double bonds, in Photochromism, Molecules and Systems, ed. H. Dürr and H. Bouas-Laurent, Elsevier, Amsterdam, 1990, pp. 64–164.
S. K. Sklar, B. Hudson, M. Petersen and J. Diamond, Conjugated polyene fatty acids as fluorescent probes: spectroscopic characterization, Biochem., 1977, 16, 813–819.
J. Klueger, G. Fischer, E. Fischer, Ch. Goedicke and H. Stegemeyer, The fluorescence of the cis and trans forms of naphthylethylenes, Chem. Phys. Lett., 1971, 8, 279–281.
Ch. Goedicke, H. Stegemeyer, G. Fischer and E. Fischer, Absorption and emission spectra of arylethylenes in the dissolved and crystalline state, Z. Phys. Chem., Neue Folge, 1976, 101, 181–196.
N. J. Turro, Modern Molecular Photochemistry, Benjamin/Cummings, Menlo Park, CA, 1978, p. 90.
N. D. Tarkalanov, Ph.D. Dissertation, Florida State University, Tallahassee, FL, USA, 2001.
A. Spalletti and G. Bartocci, Temperature and solvent effects on rotamer-specific photobehaviour of the cis and trans isomers of 2-styrylanthracene, Phys. Chem. Chem. Phys., 1999, 1, 5623–5632.
J. Saltiel and G. Krishnamoorthy, unpublished results.
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This paper is dedicated to Professor Fred Lewis on the event of his 60th birthday.
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Saltiel, J., Krishnamoorthy, G. & Sears, D.F. The effect of solvent polarizability on the fluorescence of trans-1-(2-naphthyl)-2-phenylethene conformers. Conformer-specific fluorescence from the cis isomer. Photochem Photobiol Sci 2, 1162–1168 (2003). https://doi.org/10.1039/b306404m
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DOI: https://doi.org/10.1039/b306404m