UV Laser-Induced Gas-Phase Copolymerization of Carbon Disulfide and Ethene

2004 ◽  
Vol 25 (4) ◽  
pp. 587-591 ◽  
Author(s):  
Radmila Tomovska ◽  
Markéta Urbanová ◽  
Radek Fajgar ◽  
Zdeněk Bastl ◽  
Jan Šubrt ◽  
...  
Keyword(s):  
Gas Phase ◽  
Carbon Disulfide ◽  
Uv Laser

Investigations of Excimer Laser Effects on CVD Diamond Growth

1989 ◽  
Vol 162 ◽  
Author(s):  
Pehr E. Pehrsson ◽  
H. H. Nelson ◽  
F. G. Celii
Keyword(s):  
Gas Phase ◽  
Nucleation Site ◽  
Laser Wavelength ◽  
Diamond Growth ◽  
Uv Laser ◽  
Gas Phase Chemistry ◽  
Scanning Auger Microprobe ◽  
Novel Method ◽  
Size And Morphology ◽  
Phase Chemistry

ABSTRACTWe investigated UV laser irradiation as a method to modify the surface and gas phase chemistry in a diamond growth apparatus. In particular, attempts were made to reproduce reported laser-enhanced deposition. The variables included the laser wavelength and intensity, the precursor gas (and hence the gas-phase absorption), the flow rate, and the gas inlet orientation with respect to the filament. The samples were analyzed using optical microscopy, Scanning Electron Microscopy, the Scanning Auger Microprobe, and micro-Raman scattering. In all cases, the laser radiation suppressed or had no effect on diamond deposition in comparison to the adjacent unirradiated regions. The crystals that did grow in the irradiated regions were similar in size and morphology to those from the unirradiated areas, suggesting ablation or nucleation site blockage as possible deposition suppression mechanisms. The results suggest a novel method for diamond film patterning.

Laser-induced alignment dynamics of gas phase CS2 dimers

2020 ◽  
Vol 22 (6) ◽  
pp. 3245-3253 ◽  
Author(s):  
Adam S. Chatterley ◽  
Mia O. Baatrup ◽  
Constant A. Schouder ◽  
Henrik Stapelfeldt
Keyword(s):  
Laser Pulse ◽  
Gas Phase ◽  
Carbon Disulfide ◽  
Probe Pulse ◽  
Coulomb Explosion ◽  
Rotational Dynamics ◽  
Circularly Polarized

Rotational dynamics of gas phase carbon disulfide (CS2) dimers were induced by a moderately intense, circularly polarized alignment laser pulse and measured as a function of time by Coulomb explosion imaging with an intense fs probe pulse.

Mechanism of Chromium Deposition from Cr(CO)6 by Uv Laser Light

1989 ◽  
Vol 158 ◽  
Author(s):  
R. Nowak ◽  
P. Hess
Keyword(s):  
Gas Phase ◽  
Metal Film ◽  
Film Growth ◽  
Laser Light ◽  
Film Deposition ◽  
Uv Laser ◽  
Impurity Incorporation ◽  
Metal Atoms ◽  
Chromium Films ◽  
Main Growth

ABSTRACTThe mechanism of metal film deposition from carbonyls as precursors is discussed in detail. It is shown that different species produced by UV laser irradiation in the gas phase contribute to film growth. Highly reactive species such as metal atoms may be important during the nucleation phase, whereas more stable carbonyls are responsible for the main growth process. This indicates that the main decarbonylation effect occurs at the surface. The higher level of impurity incorporation in chromium films in comparison with nickel films is explained by the relative position of the Fermi level in the d-band of Ni and Cr with respect to the 2π* level of CO, which favors CO bond dissociation in the case of chromium.

Synthesis of benzothiophenes in gas phase from aromatic hydrocarbons and carbon disulfide

1986 ◽  
Vol 30 (1) ◽  
pp. 157-163 ◽  
Author(s):  
S. Esteban ◽  
J. M. Marinas ◽  
M. P. Martinez-Alcazar ◽  
M. Martinez ◽  
A. R. Agarrabeitia
Keyword(s):  
Gas Phase ◽  
Carbon Disulfide ◽  
Aromatic Hydrocarbons

scholarly journals Unravelling the Keto-Enol Tautomer Dependent Photochemistry and Degradation Pathways of the Protonated UVA Filter Avobenzone

2020 ◽  
Author(s):  
Jacob A. Berenbeim ◽  
Natalie Wong ◽  
Martin C. R. Cockett ◽  
Giel Berden ◽  
Jos Oomens ◽  
...  
Keyword(s):  
Gas Phase ◽  
Free Electron Laser ◽  
Selective Excitation ◽  
Uv Laser ◽  
Infrared Multiple Photon Dissociation ◽  
Enol Tautomer ◽  
Ion Yields ◽  
The Stability ◽  
First Time ◽  
Insight Into

Avobenzone (AB) is a widely used UVA filter known to undergo irreversible photodegradation. Here, we investigate the detailed pathways by which AB photodegrades by applying UV laser-interfaced mass spectrometry to protonated AB ions. Gas-phase infrared multiple-photon dissociation (IRMPD) spectra obtained with the free electron laser for infrared experiments, FELIX, (600-1800 cm-1) are also presented to confirm the geometric structures. The UV gas-phase absorption spectrum (2.5-5 eV) of protonated AB contains bands that correspond to selective excitation of either the enol or diketo forms, allowing us to probe the resulting, tautomer-dependent photochemistry. Numerous photofragments (i.e. photodegradants) are directly identified for the first time, with m/z 135 and 161 dominating, and m/z 146 and 177 also appearing prominently. Analysis of the production spectra of these photofragments reveals that that strong enol to keto photoisomerism is occurring, and that protonation significantly disrupts the stability of the enol (UVA active) tautomer. Close comparison of fragment ion yields with the TDDFT-calculated absorption spectra give detailed information on the location and identity of the dissociative excited state surfaces, and thus provide new insight into the photodegradation pathways of avobenzone, and photoisomerisation of the wider class of β-diketone containing molecules.<br>

A study of the gas-phase behaviour of [Os6(CO)18] and its high yield synthesis using UV laser desorption/ionisation mass spectrometry

1999 ◽  
Vol 2 (12) ◽  
pp. 587-590 ◽  
Author(s):  
William J Dollard ◽  
Paul J Dyson ◽  
Tony Jackson ◽  
Brian F.G Johnson ◽  
J.Scott McIndoe ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Gas Phase ◽  
Laser Desorption ◽  
Phase Behaviour ◽  
High Yield ◽  
Uv Laser ◽  
Ionisation Mass Spectrometry ◽  
Ionisation Mass

scholarly journals Formation and Luminescence of Molybdenum Atoms After UV Multiphoton Excitation of Gas Phase Mo(CO)6

1992 ◽  
Vol 12 (3-4) ◽  
pp. 223-229 ◽  
Author(s):  
Yu. E. Belyayev ◽  
A. V. Dem'yanenko ◽  
A. A. Puretzky
Keyword(s):  
Gas Phase ◽  
Rydberg Atoms ◽  
Laser Excitation ◽  
Xecl Laser ◽  
Uv Laser ◽  
Delayed Luminescence ◽  
Multiphoton Excitation

The delayed luminescence of Mo atoms was observed in XeCl laser excitation of Mo(CO)6 gas. The observed luminescence was explained by production of Mo Rydberg atoms under UV laser excitation of Mo(CO)6.

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