Infrared studies have been made of several oxides of nitrogen trapped at liquid‐helium temperatures in matrices of argon, N2, O2, CO2, H2, and N2O. The novel techniques permitting these studies are described. NO is found as the monomer and two forms of dimer, ``cis'' and ``trans''; the cis is more stable. NO2 is found as the monomer, the known stable dimer of planar structure, and two new dimers; one of these has the ONO–NO2 structure, and the other may be the twisted Vd form of the stable dimer. N2O3 is found in its stable form ON–NO2 and in a second form whose spectrum is consistent with the structure ONONO. Observations on covalent N2O5 are also reported.

Infrared Spectra of the Frozen Oxides of Nitrogen

Decomposition Rates of Organic Free Radical Initiators

The thermal decomposition of nitrocellulose (NC) 12.1% N, has been studied with regard to kinetics, mechanism, morphology and the gaseous products thereof, using thermogravimetry (TG), differential thermal analysis (DTA), IR spectroscopy, differential scanning calorimetry (DSC) and hot stage microscopy. The kinetics of the initial stage of thermolysis ofNC in condensed state has been investigated by isothermal high temperature infrared spectroscopy (IR). The decomposition ofNC in KBr matrix in the temperature range of 142–151°C shows rapid decrease in O−NO2 band intensity, suggesting that the decomposition of NC occurs by the rupture of O−NO2 bond. The energy of activation for this process has been determined with the help of Avrami-Erofe'ev equation (n=1) and is ≈188.35 kJ·mol−1. Further, the IR spectra of the decomposition products in the initial stage of thermal decomposition ofNC, indicates the presence of mainly NO2 gas and aldehyde.

Studies on kinetics and mechanism of initial thermal decomposition of nitrocellulose. Isothermal and non-isothermal techniques

Quantitative Infrared Analysis of Pesticides in Solid State

Es werden die Vorzuge dargelegt, welche die KBr-Methode gegenuber anderen Praparierarten fester Stoffe (Losung, Nujolaufschlammung) bietet. Die haufig erhobenen Einwande gegen die KBr-Methode werden diskutiert und ihre Anwendungsgrenzen aufgezeigt. Sie liegen in der Hauptsache dort, wo die zu praparierenden Substanzen stoffliche Veranderungen wahrend des Presvorganges erleiden. Die moglichen Substanzveranderungen sind mannigfaltig und reichen von der teilweise oder vollstandigen Modifikationsumwandlung, der Verdampfung des Solvatlosungsmittels, der Hydratbildung, der Bildung von Molekulverbindungen, Verschiebung des Assoziations- und Enolisationsgleichgewichtes, der Reaktion mit dem KBr bis zur Dehydrierung bzw. vollstandigen Substanzzersetzung. An Hand von typischen Beispielen werden diese Vorgange erortert.

Über die Vorzüge und Grenzen der KBr-Präpariermethode in der IR-Spektrographie

Infrared Investigation of the Thermal Decomposition of Di-t-butyl Peroxide and Nitrate Esters in Potassium Halide Pressed Disks, and the Spectrum of Carbon Dioxide at High Pressures1

Henry A. Bent

Papers

Infrared Investigation of the Thermal Decomposition of Di-t-butyl Peroxide and Nitrate Esters in Potassium Halide Pressed Disks, and the Spectrum of Carbon Dioxide at High Pressures1