Volume 113, Issue 22, 08 December 2000
Index of content:
113(2000); http://dx.doi.org/10.1063/1.1330234View Description Hide Description
We report here the formation of a gas phase complex bound by a dihydrogen bond between phenol and borane-dimethylamine in supersonic jets.Laser induced fluorescence excitation, fluorescence detected infrared, and IR–UV hole-burning spectroscopies were carried out to characterize the complex. Quantum chemical calculations were used to derive the structure of the complex, providing excellent agreement with the spectroscopic data. To the best of our knowledge, we for the first time established experimentally the formation of a dihydrogen bonded complex in the gas phase.
113(2000); http://dx.doi.org/10.1063/1.1330235View Description Hide Description
A hydrogen-bonded complex of OH with CO is identified along the reaction coordinate for the reaction. The existence of this linear OH–CO complex is established by infrared action spectroscopy, which accesses vibrational stretching and bending modes of the complex. Complementary electronic structure calculations characterize the OH–CO and OH–OC complexes, the transition state for HOCO formation, and the reaction pathways that connect these complexes directly to the HOCO intermediate.
Separation of cascaded and direct fifth-order Raman signals using phase-sensitive intrinsic heterodyne detection113(2000); http://dx.doi.org/10.1063/1.1330236View Description Hide Description
Cascaded third-order Raman signals can be separated from direct two-dimensional fifth-order Raman signals using heterodyne detection with a local oscillator that is cycled from in-phase to out-of-phase with the direct signal. The difference of these scans gives the direct signal, while the sum gives the in-quadrature cascaded signal.
113(2000); http://dx.doi.org/10.1063/1.1330230View Description Hide Description
The van der Waals complex Li⋅⋅FH was formed in crossed beams and the transition state of the excited-statereaction, was accessed by photoexcitation of this complex. The dynamics of the excited-statereaction were probed by varying the excitation wavelength over the range 570–970 nm while recording the photodepletion of the complex. The findings were interpreted using high-level ab initio calculations of the ground and lowest excited-statepotential-energysurfaces.
113(2000); http://dx.doi.org/10.1063/1.1329672View Description Hide Description
A modification of the nudged elastic band method for finding minimum energy paths is presented. One of the images is made to climb up along the elastic band to converge rigorously on the highest saddle point. Also, variable spring constants are used to increase the density of images near the top of the energy barrier to get an improved estimate of the reaction coordinate near the saddle point. Applications to dissociative adsorption on Ir(111) and on Si(100) using plane wave based density functional theory are presented.