TY - JOUR
AU - Vauthey, E.
AU - Henseler, A.
TI - Energetics of Exciplex Formation Using Picosecond Transient Thermal Phase Grating Spectroscopy
PY - 1996
JF - Journal of Physical Chemistry
JA - J. Phys. Chem.
SN - 0022-3654
VL - 100
IS - 1
SP - 170
EP - 175
L1 - http://pubs.acs.org/cgi-bin/sample.cgi/jpchax/1996/100/i01/pdf/jp951849i.pdf
L2 - http://pubs.acs.org/cgi-bin/sample.cgi/jpchax/1996/100/i01/html/jp951849i.html
L3 - http://pubs.acs.org/cgi-bin/sample.cgi/jpchax/1996/100/i01/abs/jp951849i.html
M3 - 10.1021/jp951849i
UR - http://dx.doi.org/10.1021/jp951849i
N2 - A study of the energetics of electron transfer (e.t.) quenching of 9-cyanoanthracene fluorescence by aromatic (π) and aliphatic (n) donors in n-hexane using picosecond transient thermal phase grating spectroscopy is reported. The results show that the enthalpy of exciplex formation is well correlated with the redox potentials of the partners and independent of the nature of the donor, as long as exciton interaction is small. The main difference between exciplexes with donors of the two classes is the larger ground-state repulsion energy with n-donors. However, if the adiabatic ionization potentials are considered, the enthalpy of exciplex formation with n-donors is larger than expected by about 0.4 eV. These two contradictory results reflect an inconsistency between the values for adiabatic ionization potentials and oxidation potentials of n-donors. The occurrence of two distinct Rehm−Weller plots for e.t. quenching with π- and n-donors shifted by about 0.8 eV on the horizontal axis seems to originate to some extent from the use of adiabatic ionization potentials.
ID - 107
ER -

TY - JOUR
AU - Aspari, Patrizio
AU - Ghoneim, Nagwa
AU - Haselbach, Edwin
AU - Von Raumer, Markus
AU - Suppan, Paul
AU - Vauthey, Eric
TI - Photoinduced Electron Transfer between Triethylamine and Aromatic Carbonyl Compounds: the Role of the Nature of the Lowest Triplet State
PY - 1996
JF - Journal of the Chemical Society. Faraday transactions
JA - J. Chem. Soc. Faraday trans.
SN - 0956-5000
VL - 92
IS - 10
SP - 1689
EP - 1691
L1 - http://www.rsc.org/ejarchive/FT/1996/FT9969201689.pdf
L3 - http://www.rsc.org/Publishing/Journals/FT/article.asp?doi=FT9969201689
M3 - 10.1039/FT9969201689
UR - http://dx.doi.org/10.1039/FT9969201689
N2 - The rate constants of quenching of the triplet state T1 of four aromatic ketones by triethylamine in acetonitrile show no correlation with the Gibbs energy of the reaction, but depend on the nature of T1, i.e. n–π*, π–π* or charge transfer (CT) type. For example, the ratio of rate constants between two systems of n–π* and CT type, with the same driving force, is over 108. It is concluded that these reactions are kinetically controlled, the decisive factor for the activation energy being the electrostatic charge distribution of the carbonyl group in the triplet state. 
ID - 106
ER -

TY - JOUR
AU - Gumy, J.-C.
AU - Vauthey, E.
TI - Picosecond Polarization Grating Study of the Effect of Excess Excitation Energy on the Rotational Dynamics of Rhodamine 6G in Different Electronic States
PY - 1996
JF - Journal of Physical Chemistry
JA - J. Phys. Chem.
SN - 0022-3654
VL - 100
IS - 21
SP - 8628
EP - 8632
L1 - http://pubs.acs.org/doi/pdf/10.1021/jp953729g
L2 - http://pubs.acs.org/doi/full/10.1021/jp953729g
L3 - http://pubs.acs.org/doi/abs/10.1021/jp953729g
M3 - 10.1021/jp953729g
UR - http://dx.doi.org/10.1021/jp953729g
N2 - The effect of excess excitation energy on the rotational dynamics of rhodamine 6G in the ground and the first singlet excited state has been investigated in series of n-alcohols and alkanenitriles using the picosecond polarization grating technique. In nitriles, the reorientation times are the same for excitation at the S1 ← S0 and S2 ← S0 transitions, and no state dependence could be detected. In alcohols, the rotational dynamics of rhodamine 6G in the excited state is about 25% faster when formed with 1.15 eV excess excitation energy. This effect is ascribed to a decrease of the hydrodynamic volume due to dissociation of solute/solvent hydrogen bond following intramolecular vibrational redistribution. An accompanying perturbation of the solvent shell structure caused by the fast local temperature jump is not excluded.
ID - 105
ER -

TY - JOUR
AU - Hoegemann, C.
AU - Pauchard, M.
AU - Vauthey, E.
TI - Picosecond transient Grating Spectroscopy: the Nature of the Diffracted Spectrum
PY - 1996
JF - Review of Scientific Instruments
JA - Rev. Sci. Instr.
SN - 0034-6748
VL - 67
IS - 10
SP - 3449
EP - 3453
L1 - http://scitation.aip.org/deliver/fulltext/aip/journal/rsi/67/10/1.1147157.pdf?itemId=/content/aip/journal/rsi/67/10/10.1063/1.1147157&mimeType=pdf&containerItemId=content/aip/journal/rsi
L3 - http://ojps.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=RSINAK000067000010003449000001&idtype=cvips&gifs=Yes
M3 - 10.1063/1.1147157
UR - http://dx.doi.org/10.1063/1.1147157
KW - optical spectrometers
KW - visible radiation
KW - time resolution
KW - ps range
KW - absorption spectra
KW - diffraction
KW - time delay
KW - aromatics
KW - solutes
KW - comparative evaluations
N2 - A ps transient grating setup using white light continuum for probing is presented. Measurements on an aromatic molecule in solution have been carried out with this system. The diffracted spectrum is analyzed using Kogelnik’s coupled wave theory. At short time delay after excitation, the diffracted spectrum is strongly dominated by absorption and in this case transient grating spectroscopy is equivalent but more sensitive to transient absorption spectroscopy. If some of the excitation energy is dissipated as heat, the diffracted spectrum is essentially the same as the dispersion spectrum of the transient species at time delays approaching half the acoustic period. The performances of this technique and of transient absorption spectroscopy are compared.
ID - 104
ER -