Rotational effects on pyrazine S1 (1B3u) dynamics. II. Rotational temperature effects on experimental observables from a “single rotational transition”

A re-examination of the intensity distribution in the A 2 ∑ - X 2 π ultraviolet bands of OH leads to a vibrational transition moment R ev (r) = exp { — (5·97 ± 0·12) r }, where r is the internuclear distance in Ångströms. It is shown that this value for the transition moment will not explain the variation of intensity with rotational quantum number. The interaction of rotation and electronic motion leads to a second, rotational, transition moment. This term is related to the centrifugal distortion of the molecule, and for the (0, 0) band is given by R eJ (r) = exp { + (3·60 ± 1·0) x 10 -4 J ( J + 1}. Within the (0, 0) band the combination of these two moments is equivalent to a single function R e (r) = exp { — (2·67 ± 0·9) r }. In consequence (0, 0) band vibration-rotation interaction and temperature corrections remain as given by Learner (1962). The relative J dependent vibrational transition probabilities for the rest of the system are corrected. The effect of the rotational transition moment on the measurement of rotational temperature is discussed for both OH and other diatoms.

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Isotope and Temperature Effects on the Electronic Spectra of Large Carbonaceous Molecular Ions of Interstellar Relevance

Australian Journal of Chemistry ◽

10.1071/ch19206 ◽

2019 ◽

Vol 72 (11) ◽

pp. 856 ◽

Cited By ~ 1

Author(s):

Ewen K. Campbell ◽

Corey A. Rice ◽

Francois X. Hardy ◽

John P. Maier

Keyword(s):

Gas Phase ◽

Electronic Spectra ◽

Temperature Effects ◽

Near Infrared ◽

Ion Trap ◽

Rotational Temperature ◽

Blue Shift ◽

Molecular Ions ◽

Vibrational Structure ◽

Polycyclic Aromatic

The electronic spectra of isotopologues of protonated coronene in the gas phase were measured at a vibrational and rotational temperature of ~10K in a 22-pole ion trap. The (1) 1A′←X 1A′ transition of these polycyclic aromatic hydrocarbon cations with one to three carbon-13 have origin band maxima that blue-shift successively by 0.03nm. All isotopologues show distinct vibrational structure in the (1) 1A′ state. These results are compared with the effect of 13C substitution on the near infrared electronic absorptions of C60+. The (1) 1A←X 1A electronic transition of monodeuterated coronene was also recorded and its origin band is red-shifted to that of protonated coronene by 0.8nm. The implications for astronomical observations are considered.

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Space and laboratory observation of the deuterated cyanomethyl radical HDCCN

Astronomy and Astrophysics ◽

10.1051/0004-6361/202040210 ◽

2021 ◽

Vol 646 ◽

pp. L1

Author(s):

C. Cabezas ◽

Y. Endo ◽

E. Roueff ◽

N. Marcelino ◽

M. Agúndez ◽

...

Keyword(s):

Gas Phase ◽

Rotational Temperature ◽

Open Shell ◽

Rotational Transition ◽

Abundance Ratio ◽

Electric Discharges ◽

Line Pattern ◽

Laboratory Observation ◽

Deuteron Transfer ◽

Standard Gas

Our observations of TMC-1 with the Yebes 40 m radio telescope in the 31.0–50.3 GHz range allowed us to detect a group of unidentified lines, showing a complex line pattern indicative of an open-shell species. The observed frequencies of these lines and the similarity of the spectral pattern with that of the 20, 2–10, 1 rotational transition of H2CCN indicate that the lines arise from the deuterated cyanomethyl radical, HDCCN. Using Fourier transform microwave spectroscopy experiments combined with electric discharges, we succeeded in producing the radical HDCCN in the laboratory and observed its 10, 1–00, 0 and 20, 2–10, 1 rotational transitions. From our observations and assuming a rotational temperature of 5 K, we derive an abundance ratio H2CCN/HDCCN = 20 ± 4. The high abundance of the deuterated form of H2CCN is well accounted for by a standard gas-phase model, in which deuteration is driven by deuteron transfer from the H2D+ molecular ion.

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Temperature, Kinetic Energy, and Rotational Temperature Effects in Four Reactions Involving Isotopes

ACS Symposium Series - Isotope Effects in Gas-Phase Chemistry ◽

10.1021/bk-1992-0502.ch015 ◽

1992 ◽

pp. 225-245 ◽

Cited By ~ 1

Author(s):

A. A. Viggiano ◽

Robert A. Morris ◽

Jane M. van Doren ◽

John F. Paulson ◽

H. H. Michels ◽

...

Keyword(s):

Kinetic Energy ◽

Temperature Effects ◽

Rotational Temperature

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Coupling schemes for atom–diatom interactions and an adiabatic decoupling treatment of rotational temperature effects on glory scattering

The Journal of Chemical Physics ◽

10.1063/1.455198 ◽

1988 ◽

Vol 89 (2) ◽

pp. 751-761 ◽

Cited By ~ 37

Author(s):

Vincenzo Aquilanti ◽

Laura Beneventi ◽

Gaia Grossi ◽

Franco Vecchiocattivi

Keyword(s):

Temperature Effects ◽

Rotational Temperature

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Characterization of carbides in M50NiL

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100087343 ◽

1991 ◽

Vol 49 ◽

pp. 606-607

Author(s):

L. S. Lin ◽

K. P. Gumz ◽

A. V. Karg ◽

C. C. Law

Keyword(s):

Temperature Effects ◽

Base Composition ◽

Lattice Parameter ◽

Control Surface ◽

Carbide Formation ◽

Particle Sizes ◽

Low Carbon ◽

Fee Structure ◽

Heat Treated

Carbon and temperature effects on carbide formation in the carburized zone of M50NiL are of great importance because they can be used to control surface properties of bearings. A series of homogeneous alloys (with M50NiL as base composition) containing various levels of carbon in the range of 0.15% to 1.5% (in wt.%) and heat treated at temperatures between 650°C to 1100°C were selected for characterizations. Eleven samples were chosen for carbide characterization and chemical analysis and their identifications are listed in Table 1.Five different carbides consisting of M6C, M2C, M7C3 and M23C6 were found in all eleven samples examined as shown in Table 1. M6C carbides (with least carbon) were found to be the major carbide in low carbon alloys (<0.3% C) and their amounts decreased as the carbon content increased. In sample C (0.3% C), most particles (95%) encountered were M6C carbide with a particle sizes range between 0.05 to 0.25 um. The M6C carbide are enriched in both Mo and Fe and have a fee structure with lattice parameter a=1.105 nm (Figure 1).

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