Dissociative excitation of HCOOH by single-vacuum ultraviolet and two-ultraviolet photon
Dissociative excitation processes of HCOOH in the vacuum ultraviolet (VUV) region were studied by single-VUV photon with synchrotron radiation source and by two-ultraviolet (UV) photon with KrF excimer laser. In the VUV dissociation, fluorescence excitation cross sections for the OH(A) and HCOO* wer...
Gespeichert in:
Veröffentlicht in: | The Journal of chemical physics 1999-05, Vol.110 (19), p.9547-9554 |
---|---|
Hauptverfasser: | , , , , |
Format: | Artikel |
Sprache: | eng |
Online-Zugang: | Volltext |
Tags: |
Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
|
container_end_page | 9554 |
---|---|
container_issue | 19 |
container_start_page | 9547 |
container_title | The Journal of chemical physics |
container_volume | 110 |
creator | Tabayashi, Kiyohiko Aoyama, Jun-ichi Matsui, Masafuyu Hino, Takashi Saito, Ko |
description | Dissociative excitation processes of HCOOH in the vacuum ultraviolet (VUV) region were studied by single-VUV photon with synchrotron radiation source and by two-ultraviolet (UV) photon with KrF excimer laser. In the VUV dissociation, fluorescence excitation cross sections for the OH(A) and HCOO* were separately determined in the 106–155 nm region. The branching fraction was found to be a function of the VUV excitation wavelength. The magnitude is σOH(A)/[σOH(A)+σHCOO*]=0.13 at 124.5 nm and gradually increases to 0.39 at 110 nm. In the UV multiphoton dissociation at 249 nm, OH(A) and HCOO* fragments were also identified by a fluorescence spectrum. The production of OH(A) was shown to take place in the two-UV photon absorption of HCOOH. Nascent rotational and vibrational (V/R) state distributions of OH(A 2Σ+) produced via the photodissociation at a single excitation energy of 9.96 eV (124.5×1/249 nm×2), HCOOH+nhν(n=1,2)→HCO+OH(A 2Σ+), were determined by simulation analysis of the dispersed fluorescence spectra. The internal state distributions were found to be of the relaxed type, and rotational distribution could be approximated by a Boltzmann distribution. One-VUV photon excitation gave the best-fit rotational temperature Tr(v′=0)=3000 K and vibrational population ratio Nv′=1/Nv′=0=0.14, while two-UV photon excitation showed Tr(v′=0)=2000 K with Nv′=1/Nv′=0=0.12. Possible mechanisms for the OH(A) formation by both excitation sources were examined based on simple theoretical models. The degree of internal excitation is not consistent with a direct dissociation on a repulsive surface, and neither is a dissociation from a long-lived intermediate state. The formation of OH(A 2Σ+) is interpreted as dissociation of an electronically excited intermediate state, leading to the formation of OH(A)+CHO, populated competitively via an electronic predissociation process. The substantially different V/R distributions observed are dependent on the excited precursor state initially accessed, and may result from the constraint in the competing predissociation step that follows. |
doi_str_mv | 10.1063/1.478919 |
format | Article |
fullrecord | <record><control><sourceid>crossref</sourceid><recordid>TN_cdi_crossref_primary_10_1063_1_478919</recordid><sourceformat>XML</sourceformat><sourcesystem>PC</sourcesystem><sourcerecordid>10_1063_1_478919</sourcerecordid><originalsourceid>FETCH-LOGICAL-c291t-1aed335dbdf1e07a0c2b28222950149de0c8afe17602fa1921f1d00e0c7c45bb3</originalsourceid><addsrcrecordid>eNpNkM1KxDAYRYMoWEfBR8jSTcbvS3_SLKX-VBjoRsFdSdNEI51maNLqvL0j48LVvZzFWRxCrhHWCEV6i-tMlBLlCUkQSslEIeGUJAAcmSygOCcXIXwCAAqeJeTt3oXgtVPRLYaab-3i4fqRekvrqmlq2u1pcOP7YNii9Dxv6TzESS3ODyZSNfY0fnn2n-0-fPTjJTmzagjm6m9X5PXx4aWq2aZ5eq7uNkxziZGhMn2a5n3XWzQgFGje8ZJzLnPATPYGdKmsQVEAtwolR4s9wAELneVdl67IzdGrJx_CZGy7m9xWTfsWof0t0mJ7LJL-ALSFVD4</addsrcrecordid><sourcetype>Aggregation Database</sourcetype><iscdi>true</iscdi><recordtype>article</recordtype></control><display><type>article</type><title>Dissociative excitation of HCOOH by single-vacuum ultraviolet and two-ultraviolet photon</title><source>AIP Journals Complete</source><source>AIP Digital Archive</source><creator>Tabayashi, Kiyohiko ; Aoyama, Jun-ichi ; Matsui, Masafuyu ; Hino, Takashi ; Saito, Ko</creator><creatorcontrib>Tabayashi, Kiyohiko ; Aoyama, Jun-ichi ; Matsui, Masafuyu ; Hino, Takashi ; Saito, Ko</creatorcontrib><description>Dissociative excitation processes of HCOOH in the vacuum ultraviolet (VUV) region were studied by single-VUV photon with synchrotron radiation source and by two-ultraviolet (UV) photon with KrF excimer laser. In the VUV dissociation, fluorescence excitation cross sections for the OH(A) and HCOO* were separately determined in the 106–155 nm region. The branching fraction was found to be a function of the VUV excitation wavelength. The magnitude is σOH(A)/[σOH(A)+σHCOO*]=0.13 at 124.5 nm and gradually increases to 0.39 at 110 nm. In the UV multiphoton dissociation at 249 nm, OH(A) and HCOO* fragments were also identified by a fluorescence spectrum. The production of OH(A) was shown to take place in the two-UV photon absorption of HCOOH. Nascent rotational and vibrational (V/R) state distributions of OH(A 2Σ+) produced via the photodissociation at a single excitation energy of 9.96 eV (124.5×1/249 nm×2), HCOOH+nhν(n=1,2)→HCO+OH(A 2Σ+), were determined by simulation analysis of the dispersed fluorescence spectra. The internal state distributions were found to be of the relaxed type, and rotational distribution could be approximated by a Boltzmann distribution. One-VUV photon excitation gave the best-fit rotational temperature Tr(v′=0)=3000 K and vibrational population ratio Nv′=1/Nv′=0=0.14, while two-UV photon excitation showed Tr(v′=0)=2000 K with Nv′=1/Nv′=0=0.12. Possible mechanisms for the OH(A) formation by both excitation sources were examined based on simple theoretical models. The degree of internal excitation is not consistent with a direct dissociation on a repulsive surface, and neither is a dissociation from a long-lived intermediate state. The formation of OH(A 2Σ+) is interpreted as dissociation of an electronically excited intermediate state, leading to the formation of OH(A)+CHO, populated competitively via an electronic predissociation process. The substantially different V/R distributions observed are dependent on the excited precursor state initially accessed, and may result from the constraint in the competing predissociation step that follows.</description><identifier>ISSN: 0021-9606</identifier><identifier>EISSN: 1089-7690</identifier><identifier>DOI: 10.1063/1.478919</identifier><language>eng</language><ispartof>The Journal of chemical physics, 1999-05, Vol.110 (19), p.9547-9554</ispartof><lds50>peer_reviewed</lds50><woscitedreferencessubscribed>false</woscitedreferencessubscribed><citedby>FETCH-LOGICAL-c291t-1aed335dbdf1e07a0c2b28222950149de0c8afe17602fa1921f1d00e0c7c45bb3</citedby><cites>FETCH-LOGICAL-c291t-1aed335dbdf1e07a0c2b28222950149de0c8afe17602fa1921f1d00e0c7c45bb3</cites></display><links><openurl>$$Topenurl_article</openurl><openurlfulltext>$$Topenurlfull_article</openurlfulltext><thumbnail>$$Tsyndetics_thumb_exl</thumbnail><link.rule.ids>314,777,781,27905,27906</link.rule.ids></links><search><creatorcontrib>Tabayashi, Kiyohiko</creatorcontrib><creatorcontrib>Aoyama, Jun-ichi</creatorcontrib><creatorcontrib>Matsui, Masafuyu</creatorcontrib><creatorcontrib>Hino, Takashi</creatorcontrib><creatorcontrib>Saito, Ko</creatorcontrib><title>Dissociative excitation of HCOOH by single-vacuum ultraviolet and two-ultraviolet photon</title><title>The Journal of chemical physics</title><description>Dissociative excitation processes of HCOOH in the vacuum ultraviolet (VUV) region were studied by single-VUV photon with synchrotron radiation source and by two-ultraviolet (UV) photon with KrF excimer laser. In the VUV dissociation, fluorescence excitation cross sections for the OH(A) and HCOO* were separately determined in the 106–155 nm region. The branching fraction was found to be a function of the VUV excitation wavelength. The magnitude is σOH(A)/[σOH(A)+σHCOO*]=0.13 at 124.5 nm and gradually increases to 0.39 at 110 nm. In the UV multiphoton dissociation at 249 nm, OH(A) and HCOO* fragments were also identified by a fluorescence spectrum. The production of OH(A) was shown to take place in the two-UV photon absorption of HCOOH. Nascent rotational and vibrational (V/R) state distributions of OH(A 2Σ+) produced via the photodissociation at a single excitation energy of 9.96 eV (124.5×1/249 nm×2), HCOOH+nhν(n=1,2)→HCO+OH(A 2Σ+), were determined by simulation analysis of the dispersed fluorescence spectra. The internal state distributions were found to be of the relaxed type, and rotational distribution could be approximated by a Boltzmann distribution. One-VUV photon excitation gave the best-fit rotational temperature Tr(v′=0)=3000 K and vibrational population ratio Nv′=1/Nv′=0=0.14, while two-UV photon excitation showed Tr(v′=0)=2000 K with Nv′=1/Nv′=0=0.12. Possible mechanisms for the OH(A) formation by both excitation sources were examined based on simple theoretical models. The degree of internal excitation is not consistent with a direct dissociation on a repulsive surface, and neither is a dissociation from a long-lived intermediate state. The formation of OH(A 2Σ+) is interpreted as dissociation of an electronically excited intermediate state, leading to the formation of OH(A)+CHO, populated competitively via an electronic predissociation process. The substantially different V/R distributions observed are dependent on the excited precursor state initially accessed, and may result from the constraint in the competing predissociation step that follows.</description><issn>0021-9606</issn><issn>1089-7690</issn><fulltext>true</fulltext><rsrctype>article</rsrctype><creationdate>1999</creationdate><recordtype>article</recordtype><recordid>eNpNkM1KxDAYRYMoWEfBR8jSTcbvS3_SLKX-VBjoRsFdSdNEI51maNLqvL0j48LVvZzFWRxCrhHWCEV6i-tMlBLlCUkQSslEIeGUJAAcmSygOCcXIXwCAAqeJeTt3oXgtVPRLYaab-3i4fqRekvrqmlq2u1pcOP7YNii9Dxv6TzESS3ODyZSNfY0fnn2n-0-fPTjJTmzagjm6m9X5PXx4aWq2aZ5eq7uNkxziZGhMn2a5n3XWzQgFGje8ZJzLnPATPYGdKmsQVEAtwolR4s9wAELneVdl67IzdGrJx_CZGy7m9xWTfsWof0t0mJ7LJL-ALSFVD4</recordid><startdate>19990515</startdate><enddate>19990515</enddate><creator>Tabayashi, Kiyohiko</creator><creator>Aoyama, Jun-ichi</creator><creator>Matsui, Masafuyu</creator><creator>Hino, Takashi</creator><creator>Saito, Ko</creator><scope>AAYXX</scope><scope>CITATION</scope></search><sort><creationdate>19990515</creationdate><title>Dissociative excitation of HCOOH by single-vacuum ultraviolet and two-ultraviolet photon</title><author>Tabayashi, Kiyohiko ; Aoyama, Jun-ichi ; Matsui, Masafuyu ; Hino, Takashi ; Saito, Ko</author></sort><facets><frbrtype>5</frbrtype><frbrgroupid>cdi_FETCH-LOGICAL-c291t-1aed335dbdf1e07a0c2b28222950149de0c8afe17602fa1921f1d00e0c7c45bb3</frbrgroupid><rsrctype>articles</rsrctype><prefilter>articles</prefilter><language>eng</language><creationdate>1999</creationdate><toplevel>peer_reviewed</toplevel><toplevel>online_resources</toplevel><creatorcontrib>Tabayashi, Kiyohiko</creatorcontrib><creatorcontrib>Aoyama, Jun-ichi</creatorcontrib><creatorcontrib>Matsui, Masafuyu</creatorcontrib><creatorcontrib>Hino, Takashi</creatorcontrib><creatorcontrib>Saito, Ko</creatorcontrib><collection>CrossRef</collection><jtitle>The Journal of chemical physics</jtitle></facets><delivery><delcategory>Remote Search Resource</delcategory><fulltext>fulltext</fulltext></delivery><addata><au>Tabayashi, Kiyohiko</au><au>Aoyama, Jun-ichi</au><au>Matsui, Masafuyu</au><au>Hino, Takashi</au><au>Saito, Ko</au><format>journal</format><genre>article</genre><ristype>JOUR</ristype><atitle>Dissociative excitation of HCOOH by single-vacuum ultraviolet and two-ultraviolet photon</atitle><jtitle>The Journal of chemical physics</jtitle><date>1999-05-15</date><risdate>1999</risdate><volume>110</volume><issue>19</issue><spage>9547</spage><epage>9554</epage><pages>9547-9554</pages><issn>0021-9606</issn><eissn>1089-7690</eissn><abstract>Dissociative excitation processes of HCOOH in the vacuum ultraviolet (VUV) region were studied by single-VUV photon with synchrotron radiation source and by two-ultraviolet (UV) photon with KrF excimer laser. In the VUV dissociation, fluorescence excitation cross sections for the OH(A) and HCOO* were separately determined in the 106–155 nm region. The branching fraction was found to be a function of the VUV excitation wavelength. The magnitude is σOH(A)/[σOH(A)+σHCOO*]=0.13 at 124.5 nm and gradually increases to 0.39 at 110 nm. In the UV multiphoton dissociation at 249 nm, OH(A) and HCOO* fragments were also identified by a fluorescence spectrum. The production of OH(A) was shown to take place in the two-UV photon absorption of HCOOH. Nascent rotational and vibrational (V/R) state distributions of OH(A 2Σ+) produced via the photodissociation at a single excitation energy of 9.96 eV (124.5×1/249 nm×2), HCOOH+nhν(n=1,2)→HCO+OH(A 2Σ+), were determined by simulation analysis of the dispersed fluorescence spectra. The internal state distributions were found to be of the relaxed type, and rotational distribution could be approximated by a Boltzmann distribution. One-VUV photon excitation gave the best-fit rotational temperature Tr(v′=0)=3000 K and vibrational population ratio Nv′=1/Nv′=0=0.14, while two-UV photon excitation showed Tr(v′=0)=2000 K with Nv′=1/Nv′=0=0.12. Possible mechanisms for the OH(A) formation by both excitation sources were examined based on simple theoretical models. The degree of internal excitation is not consistent with a direct dissociation on a repulsive surface, and neither is a dissociation from a long-lived intermediate state. The formation of OH(A 2Σ+) is interpreted as dissociation of an electronically excited intermediate state, leading to the formation of OH(A)+CHO, populated competitively via an electronic predissociation process. The substantially different V/R distributions observed are dependent on the excited precursor state initially accessed, and may result from the constraint in the competing predissociation step that follows.</abstract><doi>10.1063/1.478919</doi><tpages>8</tpages></addata></record> |
fulltext | fulltext |
identifier | ISSN: 0021-9606 |
ispartof | The Journal of chemical physics, 1999-05, Vol.110 (19), p.9547-9554 |
issn | 0021-9606 1089-7690 |
language | eng |
recordid | cdi_crossref_primary_10_1063_1_478919 |
source | AIP Journals Complete; AIP Digital Archive |
title | Dissociative excitation of HCOOH by single-vacuum ultraviolet and two-ultraviolet photon |
url | https://sfx.bib-bvb.de/sfx_tum?ctx_ver=Z39.88-2004&ctx_enc=info:ofi/enc:UTF-8&ctx_tim=2025-01-19T11%3A26%3A42IST&url_ver=Z39.88-2004&url_ctx_fmt=infofi/fmt:kev:mtx:ctx&rfr_id=info:sid/primo.exlibrisgroup.com:primo3-Article-crossref&rft_val_fmt=info:ofi/fmt:kev:mtx:journal&rft.genre=article&rft.atitle=Dissociative%20excitation%20of%20HCOOH%20by%20single-vacuum%20ultraviolet%20and%20two-ultraviolet%20photon&rft.jtitle=The%20Journal%20of%20chemical%20physics&rft.au=Tabayashi,%20Kiyohiko&rft.date=1999-05-15&rft.volume=110&rft.issue=19&rft.spage=9547&rft.epage=9554&rft.pages=9547-9554&rft.issn=0021-9606&rft.eissn=1089-7690&rft_id=info:doi/10.1063/1.478919&rft_dat=%3Ccrossref%3E10_1063_1_478919%3C/crossref%3E%3Curl%3E%3C/url%3E&disable_directlink=true&sfx.directlink=off&sfx.report_link=0&rft_id=info:oai/&rft_id=info:pmid/&rfr_iscdi=true |