Vladimir Dribinski - Academia.edu (original) (raw)
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Papers by Vladimir Dribinski
We report the time-resolved recombination of photodissociated IBr − ͑CO 2 ͒ n ͑n =5-10͒ clusters ... more We report the time-resolved recombination of photodissociated IBr − ͑CO 2 ͒ n ͑n =5-10͒ clusters following excitation to the dissociative IBr − AЈ 2 ⌸ 1/2 state of the chromophore via a 180 fs, 795 nm laser pulse. Dissociation from the AЈ state of the bare anion results in I − and Br products. Upon solvation with CO 2 , the IBr − chromophore regains near-IR absorption only after recombination and vibrational relaxation on the ground electronic state. The recombination time was determined by using a delayed femtosecond probe laser, at the same wavelength as the pump, and detecting ionic photoproducts of the recombined IBr − cluster ions. In sharp contrast to previous studies involving solvated I 2 − , the observed recombination times for IBr − ͑CO 2 ͒ n increase dramatically with increasing cluster size, from 12 ps for n = 5 to 900 ps for n = 8 , 10. The nanosecond recombination times are especially surprising in that the overall recombination probability for these cluster ions is unity. Over the range of 5-10 solvent molecules, calculations show that the solvent is very asymmetrically distributed, localized around the Br end of the IBr − chromophore. It is proposed that this asymmetric solvation delays the recombination of the dissociating IBr − , in part through a solvent-induced well in the AЈ state that ͑for n =8,10͒ traps the evolving complex. Extensive electronic structure calculations and nonadiabatic molecular dynamics simulations provide a framework to understand this unexpected behavior.
Frontiers in Optics, 2005
The Journal of Chemical Physics, 1999
Angular distributions of state-selected NO and O products in the photoinitiated unimolecular deco... more Angular distributions of state-selected NO and O products in the photoinitiated unimolecular decomposition of jet-cooled NO2 have been measured by using both the photofragment ion imaging technique with velocity map imaging and ion time-of-flight translational spectroscopy. The recoil anisotropy parameter of the photofragments, beta, depends strongly on the rotational angular momentum of the photoproduct. O(3Pj=2,0) angular distributions are recorded at
The Journal of Chemical Physics, 2007
[sub n] clusters](https://attachments.academia-assets.com/41250051/thumbnails/1.jpg)
](The Journal of Chemical Physics, 2006
We report the time-resolved recombination of photodissociated IBr − ͑CO 2 ͒ n ͑n =5-10͒ clusters ... more We report the time-resolved recombination of photodissociated IBr − ͑CO 2 ͒ n ͑n =5-10͒ clusters following excitation to the dissociative IBr − AЈ 2 ⌸ 1/2 state of the chromophore via a 180 fs, 795 nm laser pulse. Dissociation from the AЈ state of the bare anion results in I − and Br products. Upon solvation with CO 2 , the IBr − chromophore regains near-IR absorption only after recombination and vibrational relaxation on the ground electronic state. The recombination time was determined by using a delayed femtosecond probe laser, at the same wavelength as the pump, and detecting ionic photoproducts of the recombined IBr − cluster ions. In sharp contrast to previous studies involving solvated I 2 − , the observed recombination times for IBr − ͑CO 2 ͒ n increase dramatically with increasing cluster size, from 12 ps for n = 5 to 900 ps for n = 8 , 10. The nanosecond recombination times are especially surprising in that the overall recombination probability for these cluster ions is unity. Over the range of 5-10 solvent molecules, calculations show that the solvent is very asymmetrically distributed, localized around the Br end of the IBr − chromophore. It is proposed that this asymmetric solvation delays the recombination of the dissociating IBr − , in part through a solvent-induced well in the AЈ state that ͑for n =8,10͒ traps the evolving complex. Extensive electronic structure calculations and nonadiabatic molecular dynamics simulations provide a framework to understand this unexpected behavior.
![Research paper thumbnail of Rydberg–valence interactions in CH[sub 2]Cl→CH[sub 2]+Cl photodissociation: Dependence of absorption probability on ground state vibrational excitation](https://attachments.academia-assets.com/41247296/thumbnails/1.jpg)
](The Journal of Chemical Physics, 2003
A strong enhancement of absorption to the lowest 2 A 1 state is observed for vibrationally excite... more A strong enhancement of absorption to the lowest 2 A 1 state is observed for vibrationally excited chloromethyl radicals. It is demonstrated that this enhancement is due to a significant increase in both electronic and vibrational Franck-Condon factors. Electronic structure calculations of potential energy surfaces ͑PESs͒ and transition dipole moments for the ground and the two lowest excited states of A 1 symmetry, the 1 2 A 1 valence and 2 2 A 1 Rydberg states, reveal the origin of this effect. The shelflike shape of the 1 2 A 1 PES in the Franck-Condon region and the strong dependence of the electronic transition dipole moment on C-Cl distance are responsible for the enhancement. Analysis of the shape of the electron density distribution demonstrates that Rydberg-valence interaction in the two lowest excited states causes the changes in the shape of PESs and transition dipoles with C-Cl distance.
Chemical Physics Letters, 2004
The photoexcitation of (NO)2 at 242–221 nm is studied by photoion and photoelectron imaging. A br... more The photoexcitation of (NO)2 at 242–221 nm is studied by photoion and photoelectron imaging. A broad and structureless absorption band starting at 41,300±300 cm−1 is observed. Ionization via the excited state accesses predominantly a dissociative state of (NO)2+. The broad kinetic energy distribution of the photoelectrons suggests that the excited state has a large valence component in the Franck–Condon region,
Bulletin of the American …, 2007
Potential energy curves for the ground and valence excited states of IBr$^{-}$ have been calculat... more Potential energy curves for the ground and valence excited states of IBr$^{-}$ have been calculated at the MRCI level using the MOLPRO \emph{ab initio} package. Spin-orbit coupling was calculated via a spin-orbit ECP. Charge densities, transition moments, and nonadiabatic coupling ...
Review of Scientific Instruments, 2002
In this article we present a new method for reconstructing three-dimensional ͑3D͒ images with cyl... more In this article we present a new method for reconstructing three-dimensional ͑3D͒ images with cylindrical symmetry from their two-dimensional projections. The method is based on expanding the projection in a basis set of functions that are analytical projections of known well-behaved functions. The original 3D image can then be reconstructed as a linear combination of these well-behaved functions, which have a Gaussian-like shape, with the same expansion coefficients as the projection. In the process of finding the expansion coefficients, regularization is used to achieve a more reliable reconstruction of noisy projections. The method is efficient and computationally cheap and is particularly well suited for transforming projections obtained in photoion and photoelectron imaging experiments. It can be used for any image with cylindrical symmetry, requires minimal user's input, and provides a reliable reconstruction in certain cases when the commonly used Fourier-Hankel Abel transform method fails.
We report the time-resolved recombination of photodissociated IBr − ͑CO 2 ͒ n ͑n =5-10͒ clusters ... more We report the time-resolved recombination of photodissociated IBr − ͑CO 2 ͒ n ͑n =5-10͒ clusters following excitation to the dissociative IBr − AЈ 2 ⌸ 1/2 state of the chromophore via a 180 fs, 795 nm laser pulse. Dissociation from the AЈ state of the bare anion results in I − and Br products. Upon solvation with CO 2 , the IBr − chromophore regains near-IR absorption only after recombination and vibrational relaxation on the ground electronic state. The recombination time was determined by using a delayed femtosecond probe laser, at the same wavelength as the pump, and detecting ionic photoproducts of the recombined IBr − cluster ions. In sharp contrast to previous studies involving solvated I 2 − , the observed recombination times for IBr − ͑CO 2 ͒ n increase dramatically with increasing cluster size, from 12 ps for n = 5 to 900 ps for n = 8 , 10. The nanosecond recombination times are especially surprising in that the overall recombination probability for these cluster ions is unity. Over the range of 5-10 solvent molecules, calculations show that the solvent is very asymmetrically distributed, localized around the Br end of the IBr − chromophore. It is proposed that this asymmetric solvation delays the recombination of the dissociating IBr − , in part through a solvent-induced well in the AЈ state that ͑for n =8,10͒ traps the evolving complex. Extensive electronic structure calculations and nonadiabatic molecular dynamics simulations provide a framework to understand this unexpected behavior.
Frontiers in Optics, 2005
The Journal of Chemical Physics, 1999
Angular distributions of state-selected NO and O products in the photoinitiated unimolecular deco... more Angular distributions of state-selected NO and O products in the photoinitiated unimolecular decomposition of jet-cooled NO2 have been measured by using both the photofragment ion imaging technique with velocity map imaging and ion time-of-flight translational spectroscopy. The recoil anisotropy parameter of the photofragments, beta, depends strongly on the rotational angular momentum of the photoproduct. O(3Pj=2,0) angular distributions are recorded at
The Journal of Chemical Physics, 2007
The Journal of Chemical Physics, 2006
We report the time-resolved recombination of photodissociated IBr − ͑CO 2 ͒ n ͑n =5-10͒ clusters ... more We report the time-resolved recombination of photodissociated IBr − ͑CO 2 ͒ n ͑n =5-10͒ clusters following excitation to the dissociative IBr − AЈ 2 ⌸ 1/2 state of the chromophore via a 180 fs, 795 nm laser pulse. Dissociation from the AЈ state of the bare anion results in I − and Br products. Upon solvation with CO 2 , the IBr − chromophore regains near-IR absorption only after recombination and vibrational relaxation on the ground electronic state. The recombination time was determined by using a delayed femtosecond probe laser, at the same wavelength as the pump, and detecting ionic photoproducts of the recombined IBr − cluster ions. In sharp contrast to previous studies involving solvated I 2 − , the observed recombination times for IBr − ͑CO 2 ͒ n increase dramatically with increasing cluster size, from 12 ps for n = 5 to 900 ps for n = 8 , 10. The nanosecond recombination times are especially surprising in that the overall recombination probability for these cluster ions is unity. Over the range of 5-10 solvent molecules, calculations show that the solvent is very asymmetrically distributed, localized around the Br end of the IBr − chromophore. It is proposed that this asymmetric solvation delays the recombination of the dissociating IBr − , in part through a solvent-induced well in the AЈ state that ͑for n =8,10͒ traps the evolving complex. Extensive electronic structure calculations and nonadiabatic molecular dynamics simulations provide a framework to understand this unexpected behavior.
The Journal of Chemical Physics, 2003
A strong enhancement of absorption to the lowest 2 A 1 state is observed for vibrationally excite... more A strong enhancement of absorption to the lowest 2 A 1 state is observed for vibrationally excited chloromethyl radicals. It is demonstrated that this enhancement is due to a significant increase in both electronic and vibrational Franck-Condon factors. Electronic structure calculations of potential energy surfaces ͑PESs͒ and transition dipole moments for the ground and the two lowest excited states of A 1 symmetry, the 1 2 A 1 valence and 2 2 A 1 Rydberg states, reveal the origin of this effect. The shelflike shape of the 1 2 A 1 PES in the Franck-Condon region and the strong dependence of the electronic transition dipole moment on C-Cl distance are responsible for the enhancement. Analysis of the shape of the electron density distribution demonstrates that Rydberg-valence interaction in the two lowest excited states causes the changes in the shape of PESs and transition dipoles with C-Cl distance.
Chemical Physics Letters, 2004
The photoexcitation of (NO)2 at 242–221 nm is studied by photoion and photoelectron imaging. A br... more The photoexcitation of (NO)2 at 242–221 nm is studied by photoion and photoelectron imaging. A broad and structureless absorption band starting at 41,300±300 cm−1 is observed. Ionization via the excited state accesses predominantly a dissociative state of (NO)2+. The broad kinetic energy distribution of the photoelectrons suggests that the excited state has a large valence component in the Franck–Condon region,
Bulletin of the American …, 2007
Potential energy curves for the ground and valence excited states of IBr$^{-}$ have been calculat... more Potential energy curves for the ground and valence excited states of IBr$^{-}$ have been calculated at the MRCI level using the MOLPRO \emph{ab initio} package. Spin-orbit coupling was calculated via a spin-orbit ECP. Charge densities, transition moments, and nonadiabatic coupling ...
Review of Scientific Instruments, 2002
In this article we present a new method for reconstructing three-dimensional ͑3D͒ images with cyl... more In this article we present a new method for reconstructing three-dimensional ͑3D͒ images with cylindrical symmetry from their two-dimensional projections. The method is based on expanding the projection in a basis set of functions that are analytical projections of known well-behaved functions. The original 3D image can then be reconstructed as a linear combination of these well-behaved functions, which have a Gaussian-like shape, with the same expansion coefficients as the projection. In the process of finding the expansion coefficients, regularization is used to achieve a more reliable reconstruction of noisy projections. The method is efficient and computationally cheap and is particularly well suited for transforming projections obtained in photoion and photoelectron imaging experiments. It can be used for any image with cylindrical symmetry, requires minimal user's input, and provides a reliable reconstruction in certain cases when the commonly used Fourier-Hankel Abel transform method fails.