Photodissociation of the OD radical at 226 and 243 nm

The photodissociation dynamics of state selected OD radicals has been examined at 243 and 226 nm using velocity map imaging to probe the angle–speed distributions of theD(2S) and O(3P2) products. Both experiment and complementary first principle calculations demonstrate that photodissociation occurs by promotion of OD from high vibrational levels of the ground X 2Π state to the repulsive 1 2Σ− state

Iron monoxide photodissociation

Contains fulltext : 32657.pdf (publisher's version ) (Open Access

Cluster-enhanced X-O-2 photochemistry (X=CH3I, C3H6, C6H12, and Xe)

Contains fulltext : 34995.pdf (publisher's version ) (Open Access)The effect of a local environment on the photodissociation of molecular oxygen is investigated in the van der Waals complex X-O-2 (X=CH3I, C3H6, C6H12, and Xe). A single laser operating at wavelengths around 226 nm is used for both photodissociation of the van der Waals complex and simultaneous detection of the O(P-3(J),J=2,1,0) atom photoproduct via (2+1) resonance enhanced multiphoton ionization. The kinetic energy distribution (KED) and angular anisotropy of the product O atom recoil in this dissociation are measured using the velocity map imaging technique configured for either full ("crush") or partial ("slice") detection of the three-dimensional O(P-3(J)) atom product Newton sphere. The measured KED and angular anisotropy reveal a distinct difference in the mechanism of O atom generation from an X-O-2 complex compared to a free O-2 molecule. The authors identify two one-photon excitation pathways, the relative importance of which depends on IPx, the ionization potential of the X partner. One pathway, observed for all complexes independent of IPx, involves a direct transition to the perturbed covalent state X-O-2(A('3)Delta(u)) with excitation localized on the O-2 subunit. The predominantly perpendicular character of this channel relative to the laser polarization detection, together with data on the structure of the complex, allows us to confirm that X partner induced admixing of an X+-O-2(-) charge transfer (CT) state is the perturbing factor resulting in the well-known enhancement of photoabsorption within the Herzberg continuum of molecular oxygen. The second excitation pathway, observed for X-O-2 complexes with X=CH3I and C3H6, involves direct excitation into the (3)(X+-O-2(-)) CT state of the complex. The subsequent photodissociation of this CT state by the same laser pulse gives rise to the superoxide anion O-2(-), which then photodissociates, providing fast (0.69 eV) O atoms with a parallel image pattern. Products from the photodissociation of singlet oxygen O-2(b (1)Sigma(+)(g)) are also observed when the CH3I-O-2 complex was irradiated. Potential energy surfaces (PES) for the ground and relevant excited states of the X-O-2 complex have been constructed for CH3I-O-2 using the results of CASSCF calculations for the ground and CT states of the complex as well as literature data on PES of the subunits. These model potential energy surfaces allowed us to interpret all of the observed O(P-3(J)) atom production channels. (c) 2007 American Institute of Physics

Photofragment alignment in the photodissociation of I-2 from 450 to 510 nm

Contains fulltext : 35565.pdf (publisher's version ) (Open Access)A combination of velocity map imaging and slicing techniques have been used to measure the product recoil anisotropy and angular momentum polarization for the photodissociation process I-2-> I(P-2(3/2))+I(P-2(3/2)) and I-2-> I(P-2(3/2))+I(P-2(1/2)) in the 450-510 nm laser wavelength region using linearly polarized photolysis and probe laser light. The former channel is produced predominantly via perpendicular excitation to the (1)Pi(u) state, and the latter is predominantly parallel, via the B (3)Pi(0(u))(+) state. In both cases we observe mostly adiabatic dissociation, which produces electronically aligned iodine atoms in the parallel to m parallel to=1/2 states with respect to the recoil direction. (c) 2006 American Institute of Physics

Comment on "Unraveling the mysteries of metastable O-4 J. Chem. Phys. 110, 6095 (1999)

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Pulsed source of metal atoms and their compounds

Contains fulltext : 32886.pdf (publisher's version ) (Open Access

UV photodissociation of the van der Waals dimmer (CH3I)2 revisited: pathways giving rise to ionic features

Contains fulltext : 33129.pdf (publisher's version ) (Open Access

Imaging the dynamics of gas phase reactions

Contains fulltext : 35734.pdf (publisher's version ) (Open Access)Ion imaging methods are making ever greater impact on studies of gas phase molecular reaction dynamics. This article traces the evolution of the technique, highlights some of the more important breakthroughs with regards to improving image resolution and in image processing and analysis methods, and then proceeds to illustrate some of the many applications to which the technique is now being applied-most notably in studies of molecular photodissociation and of bimolecular reaction dynamics

Photodissociation of the OD radical at 226 and 243 nm

Contains fulltext : 103947.pdf (publisher's version ) (Open Access

Photodissociation of O2 in the Herzberg Continuum

Contains fulltext : 36187.pdf (Publisher’s version ) (Open Access)RU, Molecular and Laser Physics, 06 maart 2006Promotor : Parker, D.H.165 p