Spectroscopic Study of the Vacuum-Ultraviolet Photolysis of Matrix-Isolated HCN and Halogen Cyanides. Infrared Spectra of the Species CN and XNC

Abstract

Yes, since V does not have sites both in X and Z, it must be a subfigure of XV, YZ, or both. To be specific, suppose V is a subfigure of XV. By hypothesis PIV} is consistent with PIXY}, and we have shown that PIXY} is consistent with P{U}. Therefore, since V is a subfigure of XV, which in turn is a subfigure of U, it follows that P{ V} is consistent with P{U}=P{XY}P{YZ}/P{ V}. Statement (b) is proven by noting P{ U} = P{XYZ} = P{ Y} Py{XZ} and P{ U} = P{ X Y} P{ YZ} / P{ Y} = P { Y} Py{ X} Py{Z} ;thus Py{XZ} = Py{X} Py{Z}. Equations (6) and (7) now lead to the desired result. THE JOURNAL OF CHEMICAL PHYSICS To prove (c), we first write S(P{ UI) = S(P{XYZI) = S(P{ Y}) + LP{ Yl S(Py{XZ}), y in accordance with Eq. (2). A well-known theorem of information theory!2 states S(Py{XZ}) S S(Py{X}) + S(Py{Z}). Therefore S(P{ U})::; S(P{ Y}) + LP{ Y} S(Py{X}) y + LP{ YI S(Py{Z}) , y or with the aid of Eq. (2), S(P{ U})::; S(P{XY}) +S(P{ YZ}) -S(P{ Y}).12Vacuum-ultraviolet photolysis of HCN isolated in Ar and N2 matrices at 14°K is found to lead to the production of HNC in concentration sufficient for direct infrared observation of all three vibrational fundamentals. The spectrum of this species is found to be appreciably perturbed by the presence of N2. The force constants and thermodynamic properties of HNC have been revised to the values appropriate to this species in an environment free of perturbation by an adjacent N, molecule. The free radical CN is also produced in these systems in concentration sufficient for direct observation not only of the B (2];+)-X (2];+) transition but also of the ground-state vibrational fundamental. Isotopic data supporting this identification are presented. Upon vacuum-ultraviolet photolysis of matrix-isolated FCN, two infrared absorptions appear which can be identified with the stretching fundamentals of the species FNC. In analogous experiments on the species CICN and BrCN, infrared absorptions tentatively assigned to CINC and BrNC have been observed.

Experimental Study of Water−Ice Catalyzed Thermal Isomerization of Cyanamide into Carbodiimide: Implication for Prebiotic Chemistry

“…Indeed, as it has been already reported for HCN and HC 3 N which can be converted into CNH 19 and CCCNH 20 by VUV irradiation, in the same way we observed that solid NH 2 CN leads to monomer HNCNH trapped in solid NH 2 CN (Figure 2). The outcome is that the band at 2125 cm -1 grows at the beginning of the UV process and then decreases when the amount of carbodiimide becomes higher in the sample.…”

Reactions of nitriles in ices relevant to Titan, comets, and the interstellar medium: formation of cyanate ion, ketenimines, and isonitriles

“…15. That we see nitrile-to-isonitrile conversions in N 2 is not surprising, as they have been observed in rare-gas matrices (e.g., Milligan and Jacox, 1967). Less expected is that these reactions also Fig.…”

New data on photochemistry of the interstellar molecule: HNCS. Identification of the S⋯HCN complex

“…26,27 They are however shifted by À88.0 and +25.5 cm À1 (À65.0 and +17.5/17.0 for solid nitrogen), respectively, relative to the positions of the HCN monomer absorptions. The observed shifts strongly suggest that these bands originate from complexed hydrogen cyanate molecules.…”