Photodissociation of t-butyl nitrite on Ag(111): rotational and electronic-state distributions of the NO (X2Π) photofragments

Photodissociation Dynamics of tert-Butyl Nitrite on Ag(111): Characterization of Translationally and Internally Excited NO Fragments

“…These three components are attributed to collisionless ejection (a), release after becoming fully thermalized (b), and ejection after one or a few collisions (c). We conclude that, as for 248 nm photolysis, , there is correlation among translational, vibrational, and rotational energies. For example, NO arriving at the detector with little rotational and vibrational energy is also moving slowly, component b, whereas rapidly moving NO, component a, includes negligible amounts of NO in ν‘ ‘ = 0.…”

“…Internal State Distributions . The two-photon excitation spectra of the NO A 2 Σ + (ν‘ = 0) ← NO X 2 Π (ν‘ ‘ = 0, 1, 2) transitions are known from the literature, − and the analysis procedure used to extract rotational and vibrational state distributions was similar to that described previously . Briefly, experimental spectra were compared with the spectra calculated using the known spectroscopic constants 40 by convoluting computed spectral lines with an experimental bandwidth.…”

“…The ultrahigh vacuum (UHV) chamber and laser system is described in more detail elsewhere. − Briefly, the experiments were done in a two-level UHV chamber, which operates at a base pressure of < 2 × 10 -10 Torr. An ion gun, reverse-view low-energy electron diffraction (LEED) apparatus, and Auger electron spectrometer comprise the upper level, where the substrate is cleaned and analyzed.…”

“…As for earlier work, the results conform to direct photodissociation with no measurable contributions from substrate-mediated excitation. Zhao et al measured the rotational and electronic state distributions of the NO photofragments produced at 248 nm. The fastest NO is characterized by a quite narrow nonthermal Gaussian distribution of high- J states, peaking at J = 54.5 ± 1, while the slowest NO is characterized by a Boltzmann distribution of low- J states with a temperature close to that of the substrate (∼100 K).…”

Low-temperature reactions in the chemistry of nanosystems

“…201 Controlled adsorption and decomposition of iron pentacarbonyl, chromium hexacarbonyl and cyclopentadienylrhodium dicarbonyl on the single-crystal surfaces of Ag, Pt, Au and Cu at 80 ± 300 K were studied by reflection absorption IR spectroscopy. 202,203 Photodissociation of neutral molecules on cold surfaces of various metals was studied; some examples are provided by the CH 3 I/Cu(110), 204 Bu t NO 2 /Ag(111) 205 and NH 3 /Pt (111), Ge(100), Si(100) pairs. 206,207 Yet another promising method of cryochemical research, which allows preparation of hybrid nanostructures, involves the action of aggressive gases on the surface of metal crystals at low temperatures.…”