Volume 118, Issue 20, 22 May 2003
Index of content:
118(2003); http://dx.doi.org/10.1063/1.1574789View Description Hide Description
The fluorescence excitation spectra of single chromophores in a solid often consist of several components at low temperature, which is due to the interaction with matrix two-level systems (TLSs). For a number of terrylene molecules in -hexadecane we observed electric-field-induced changes of the intensity and splitting of the spectral components. With some basic assumptions the data allow us to calculate all the characteristic parameters of a single TLS, viz., the (zero field) asymmetry, the tunnel parameter, and the permanent electric dipole moment. In one case we found an exceptionally large dipole moment of about 8 Debye.
118(2003); http://dx.doi.org/10.1063/1.1576386View Description Hide Description
In this letter, we report the photodissociation of styrene at 193 nm by product translational spectroscopy. The results show that the molecule undergoes predominantly molecular elimination of and with a branching ratio In addition, a secondary dissociation channel from the internally excited product was identified. Product translational energy distributions were measured for all reaction channels. The lack of the product anisotropy is consistent with previous investigations that fragment separation occurred after structural rearrangement.
118(2003); http://dx.doi.org/10.1063/1.1576387View Description Hide Description
We report a study on the spectroscopy and the photochemistry of the allyl radical, in the vacuum ultraviolet energy range using synchrotron radiation as the light source and a flash pyrolysis source to generate the radical. Mass spectra recorded over a wide energy range show the appearance of as a fragment in the dissociative photoionization of allyl above 10 eV. The threshold photoelectron spectrum of the allyl radical shows a progression of around 52 meV, corresponding to the CCC bending vibration.
118(2003); http://dx.doi.org/10.1063/1.1576218View Description Hide Description
The curvature dependence of the surface tension of one-component droplets and bubbles is determined approximately. In the scope of the approximation used, it is found that for both droplets and bubbles of any size the surface tension diminishes monotonically with decreasing the radius of the surface of tension.