ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTPhotochemistry of diacetyleneS. Glicker and H. OkabeCite this: J. Phys. Chem. 1987, 91, 2, 437–440Publication Date (Print):January 1, 1987Publication History Published online1 May 2002Published inissue 1 January 1987https://pubs.acs.org/doi/10.1021/j100286a036https://doi.org/10.1021/j100286a036research-articleACS PublicationsRequest reuse permissionsArticle Views294Altmetric-Citations61LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access options Get e-Alerts

Laser-induced fluorescence of the CN(B 2Σ+–X 2Σ+) electronic system was used to study the internal energy partitioning of CN radicals produced by the photolysis of HC2CN and CH3CN at λ≳130 nm. Experiments were performed in two collision regimes: (1) in the low collision number regime, the rotational and vibrational level distributions of CN(X) produced by the photolysis were measured; (2) in the high collision number experiments, the formation of CN(A) was monitored. Photolysis of HC2CN produced CN predominantly in the X state; Table I contains the vibrational population ratios and the temperatures computed from a Boltzmann fit of the rotational levels. Photolysis of CH3CN produces CN predominantly in the A 2Πi state; a lower limit of 0.3 was measured for the v′=1/v′=0 vibrational population ratio.

Solid films of H2CO:D2CO mixtures have been photolyzed at 123.6 and 147 nm. The isotopic distribution of molecular hydrogen was determined by end-product analysis. Using the hydrogen distribution, an estimate was made of the overall molecular processes, i.e., 40% and 49% at 123.6 and 147 nm, respectively. Implications of this work relative to the mechanism and other related low-temperature studies are discussed.

The relative efficiencies for two dissociative channels in the vacuum UV photolysis of carbonyl sulphide have been determined using the flash photolysis-resonance fluorescence technique to measure initial yields of atomic oxygen and atomic sulphur. At wavelengths above 105 nm, the dissociation of OCS to form atomic sulphur exceeded that for the formation of atomic oxygen to such an extent that only an upper limit could be placed on the minor process, ΦS >/ 50 ΦO. In addition, the flash photo-excitation of carbonyl sulphide produced a long-lived spontaneous emission in the UV and vacuum UV that might be due to molecular fluorescence from OCS.

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTRapid gas-phase reactions. Reaction of ammonia and the methylamines with boron trifluoride. III. Pressure dependence of rate constantSol GlickerCite this: J. Phys. Chem. 1973, 77, 9, 1093–1095Publication Date (Print):April 1, 1973Publication History Published online1 May 2002Published inissue 1 April 1973https://pubs.acs.org/doi/10.1021/j100628a002https://doi.org/10.1021/j100628a002research-articleACS PublicationsRequest reuse permissionsArticle Views56Altmetric-Citations3LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access options Get e-Alerts

The photolysis of formaldehyde vapor has been examined at 1470 and 1236 Å. Mixed isotope (H2CO+D2CO) and radical scavenger (C2D4) experiments have been utilized in addition to inert gas pressurization and lamp intensity attenuation. The quantum yields for H2 and CO formation are both equal to 2; and both are independent of pressure and lamp intensity at 1470 and 1236 Å. The primary quantum yield for molecular hydrogen elimination (ΦII) was determined from the scavenger results and also from the mixed isotope work. The two values obtained are in reasonably good agreement, viz., ΦII = 0.5. The mechanism most consistent with the experimental observations is as follows: H2CO+hυ→H2+CO, H2CO+hυ→2H+CO, H+H2CO→H2+HCO, 2HCO→H2+2CO, where the quantum yields of primary process (II) and (III) are both equal to 0.5.