The Infrared Spectra of Nitriles and Related Compounds Frozen in AR and H 2O

Details The Infrared Spectra of Nitriles and Related Compounds Frozen in AR and H 2O The Infrared Spectra of Nitriles and Related Compounds Frozen in AR and H 2O

Feb 1997

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1997apj...476..932b&link_type=abstract

Astrophysical Journal v.476, p.932

Astronomy and Astrophysics

Astronomy

37

Infrared: General, Methods: Laboratory, Molecular Data

Scientific paper

We present the 2320--2050 cm-1 (4.31--4.88 mu m) infrared spectra of 16 solid-state nitriles, isonitriles, and related compounds in order to facilitate the assignment of absorption features in a spectral region now becoming accessible to astronomers for the first time through the Infrared Space Observatory (ISO). This frequency range spans the positions of the strong C=N stretching vibration of these compounds and is inaccessible from the ground due to absorption by CO2 in the terrestrial atmosphere. Band positions, profiles, and intrinsic strengths (A values) were measured for compounds frozen in Ar and H2O matrices at 12 K. The molecular species examined included acetonitrile, benzonitrile (phenylcyanide), 9-anthracenecarbonitrile, dimethylcyanamide, isopropylnitrile (isobutyronitrile), methylacrylonitrile, crotononitrile, acrylonitrile (vinyl cyanide), 3-aminocrotononitrile, pyruvonitrile, dicyandiamide, cyanamide, n-butylisocyanide, methylisocyanoacetate, diisopropylcarbodiimide, and hydrogen cyanide. The C=N stretching bands of the majority of nitriles fall in the 2300--2200 cm-1 (4.35--4.55 mu m) range and have similar positions in both Ar and H2O matrices, although the bands are generally considerably broader in the H2O matrices. In contrast, the isonitriles and a few exceptional nitriles and related species produce bands at lower frequencies spanning the 2200--2080 cm-1 (4.55--4.81 mu m) range. These features also have similar positions in both Ar and H2O matrices, and the bands are broader in the H2O matrices. Three of the compounds (pyruvonitrile, dicyandiamide, and cyanamide) show unusually large shifts of their C=N stretching frequencies when changing from Ar to H2O matrices. We attribute these shifts to the formation of H2O:nitrile complexes with these compounds. The implications of these results for the identification of the 2165 cm-1 (4.62 mu m) "XCN" interstellar feature and the 4550 cm-1 (2.2 mu m) feature of various objects in the solar system are discussed.

Affiliated with

Also associated with

No associations

Rating

The Infrared Spectra of Nitriles and Related Compounds Frozen in AR and H 2O does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with The Infrared Spectra of Nitriles and Related Compounds Frozen in AR and H 2O, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The Infrared Spectra of Nitriles and Related Compounds Frozen in AR and H 2O will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1775624