Source:http://linkedlifedata.com/resource/pubmed/id/16480292
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| Predicate | Object |
|---|---|
| rdf:type | |
| lifeskim:mentions | |
| pubmed:issue |
7
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| pubmed:dateCreated |
2006-2-16
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| pubmed:abstractText |
We measured angular-anisotropy parameters beta(E(t)) of fragments from photolysis of ethene and four isotopic variants at 157 nm using photo-fragment translational spectroscopy and selective photoionization. The averaged beta value of products ranges from -0.17 to 0.10, depending on dissociation pathways. Angular distributions of atomic hydrogen produced from C(2)H(4) and C(2)D(4) are isotropic. For dissociation into C(2)H(2) + H(2), beta has a small negative value whereas dissociation into C(2)D(2) + D(2) has an isotropic angular distribution. The photolysis of dideuterated ethene reveals site and isotopic effects on the angular distributions of products; products H(2), HD, and D(2) from photolysis of 1,1-CH(2)CD(2) have negative, nearly zero, and positive values of beta, respectively. Molecular hydrogen from photolysis of 1,2-cis-CHDCHD has a negative beta value and the anisotropy has a trend D(2) > H(2) > HD. Photolysis of 1,2-trans-CHDCDH produced a result similar to photolysis of 1,2-cis-CHDCHD for the angular anisotropy of molecular hydrogen except slightly more isotropic. A calculation of optimized geometries of ethene in the ground electronic state and pertinent transition structures enables a qualitative interpretation of the site and isotopic effects on the angular anisotropy of products. We deduce that the photoexcited state of ethene at 157 nm has a major character (1)B(1u) that produces a transition dipolar moment parallel to the C=C bond.
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| pubmed:language |
eng
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| pubmed:journal | |
| pubmed:status |
PubMed-not-MEDLINE
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| pubmed:month |
Feb
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| pubmed:issn |
1089-5639
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| pubmed:author | |
| pubmed:issnType |
Print
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| pubmed:day |
23
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| pubmed:volume |
110
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| pubmed:owner |
NLM
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| pubmed:authorsComplete |
Y
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| pubmed:pagination |
2337-44
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| pubmed:year |
2006
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| pubmed:articleTitle |
Site and isotopic effects on the angular anisotropy of products in the photodissociation of ethene at 157 nm.
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| pubmed:affiliation |
National Synchrotron Radiation Research Center, 101 Hsin-Ann Road, Hsinchu Science Park, Hsinchu 30076, Taiwan. shlee@nsrrc.org.tw
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| pubmed:publicationType |
Journal Article
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