File Download

There are no files associated with this item.

  Links for fulltext
     (May Require Subscription)
Supplementary

Article: A theoretical investigation of p-hydroxyphenacyl caged phototrigger compounds: How water induces the photodeprotection and subsequent rearrangement reactions

TitleA theoretical investigation of p-hydroxyphenacyl caged phototrigger compounds: How water induces the photodeprotection and subsequent rearrangement reactions
Authors
Issue Date2007
PublisherAmerican Chemical Society. The Journal's web site is located at http://pubs.acs.org/journal/jpcbfk
Citation
Journal Of Physical Chemistry B, 2007, v. 111 n. 40, p. 11832-11842 How to Cite?
AbstractComplete active-space self-consistent field (CASSCF) calculations with a (14,11) active space and density functional theory calculations followed by Car-Parrinello molecular dynamic simulations are reported for the p-hydroxyphenacyl acetate, diethyl phosphate, and diphenyl phosphate phototrigger compounds. These calculations considered the explicit hydrogen bonding of water molecules to the phototrigger compound and help reveal the role of water in promoting the photodeprotection and subsequent rearrangement reactions for the p-hydroxyphenacyl caged phototrigger compounds experimentally observed in the presence of appreciable amounts of water but not observed in neat nonproton solvents like acetonitrile. The 267 nm excitation of the phototrigger compounds leads to an instantaneous population of the S 3( 1ππ*) state Franck-Condon region, which is followed by an internal conversion deactivation route to the S 1( 1ππ*) state via a 1ππ*/ 1nπ* vibronic coupling. The shorter lifetime of the S 1( 1nπ*) state (∼1 ps) starting from the FC geometry is terminated by a fast intersystem crossing at a 3ππ*/ 3nπ* intersection with a structure of mixed ππ*/nπ* excitation in the triplet state. The deprotection reaction is triggered by a proton (or hydrogen atom) transfer assisted by water bridges and emanates from this ππ*/nπ* triplet state intersection. With the departure of the leaving group, the reaction evolves into a water-mediated post-deprotection phase where the spin inversion of pQM (X, 3A) leads to a spiroketone in the ground state by a cyclization process that is followed by an attack of water to produce a 1,1′-di-hydroxyl-spiroketone. Finally, the H atom of the hydroxyl in 1,1′-di-hydroxyl-spiroketon transfers back to the p-O atom aided by water molecules to generate the p-hydroxyphenyl-acetic acid final rearrangement product. © 2007 American Chemical Society.
Persistent Identifierhttp://hdl.handle.net/10722/69444
ISSN
2015 Impact Factor: 3.187
2015 SCImago Journal Rankings: 1.414
ISI Accession Number ID
References

 

DC FieldValueLanguage
dc.contributor.authorChen, Xen_HK
dc.contributor.authorChensheng, Men_HK
dc.contributor.authorKwok, WMen_HK
dc.contributor.authorGuan, Xen_HK
dc.contributor.authorDu, Yen_HK
dc.contributor.authorPhillips, DLen_HK
dc.date.accessioned2010-09-06T06:13:43Z-
dc.date.available2010-09-06T06:13:43Z-
dc.date.issued2007en_HK
dc.identifier.citationJournal Of Physical Chemistry B, 2007, v. 111 n. 40, p. 11832-11842en_HK
dc.identifier.issn1520-6106en_HK
dc.identifier.urihttp://hdl.handle.net/10722/69444-
dc.description.abstractComplete active-space self-consistent field (CASSCF) calculations with a (14,11) active space and density functional theory calculations followed by Car-Parrinello molecular dynamic simulations are reported for the p-hydroxyphenacyl acetate, diethyl phosphate, and diphenyl phosphate phototrigger compounds. These calculations considered the explicit hydrogen bonding of water molecules to the phototrigger compound and help reveal the role of water in promoting the photodeprotection and subsequent rearrangement reactions for the p-hydroxyphenacyl caged phototrigger compounds experimentally observed in the presence of appreciable amounts of water but not observed in neat nonproton solvents like acetonitrile. The 267 nm excitation of the phototrigger compounds leads to an instantaneous population of the S 3( 1ππ*) state Franck-Condon region, which is followed by an internal conversion deactivation route to the S 1( 1ππ*) state via a 1ππ*/ 1nπ* vibronic coupling. The shorter lifetime of the S 1( 1nπ*) state (∼1 ps) starting from the FC geometry is terminated by a fast intersystem crossing at a 3ππ*/ 3nπ* intersection with a structure of mixed ππ*/nπ* excitation in the triplet state. The deprotection reaction is triggered by a proton (or hydrogen atom) transfer assisted by water bridges and emanates from this ππ*/nπ* triplet state intersection. With the departure of the leaving group, the reaction evolves into a water-mediated post-deprotection phase where the spin inversion of pQM (X, 3A) leads to a spiroketone in the ground state by a cyclization process that is followed by an attack of water to produce a 1,1′-di-hydroxyl-spiroketone. Finally, the H atom of the hydroxyl in 1,1′-di-hydroxyl-spiroketon transfers back to the p-O atom aided by water molecules to generate the p-hydroxyphenyl-acetic acid final rearrangement product. © 2007 American Chemical Society.en_HK
dc.languageengen_HK
dc.publisherAmerican Chemical Society. The Journal's web site is located at http://pubs.acs.org/journal/jpcbfken_HK
dc.relation.ispartofJournal of Physical Chemistry Ben_HK
dc.titleA theoretical investigation of p-hydroxyphenacyl caged phototrigger compounds: How water induces the photodeprotection and subsequent rearrangement reactionsen_HK
dc.typeArticleen_HK
dc.identifier.openurlhttp://library.hku.hk:4550/resserv?sid=HKU:IR&issn=1520-6106&volume=111&spage=11832&epage=11842&date=2007&atitle=A+Theoretical+Investigation+of+P-Hydroxyphenacyl+Caged+Phototrigger+Compounds:+How+Water+Induces+the+Photodeprotection+and+Subsequent+Rearrangement+Reactionsen_HK
dc.identifier.emailChensheng, M:macs@hkucc.hku.hken_HK
dc.identifier.emailPhillips, DL:phillips@hku.hken_HK
dc.identifier.authorityChensheng, M=rp00758en_HK
dc.identifier.authorityPhillips, DL=rp00770en_HK
dc.description.naturelink_to_subscribed_fulltext-
dc.identifier.doi10.1021/jp073529sen_HK
dc.identifier.pmid17867669-
dc.identifier.scopuseid_2-s2.0-35548985483en_HK
dc.identifier.hkuros143578en_HK
dc.relation.referenceshttp://www.scopus.com/mlt/select.url?eid=2-s2.0-35548985483&selection=ref&src=s&origin=recordpageen_HK
dc.identifier.volume111en_HK
dc.identifier.issue40en_HK
dc.identifier.spage11832en_HK
dc.identifier.epage11842en_HK
dc.identifier.isiWOS:000249986900034-
dc.publisher.placeUnited Statesen_HK
dc.identifier.scopusauthoridChen, X=9279664000en_HK
dc.identifier.scopusauthoridChensheng, M=7402924979en_HK
dc.identifier.scopusauthoridKwok, WM=7103129332en_HK
dc.identifier.scopusauthoridGuan, X=8313149700en_HK
dc.identifier.scopusauthoridDu, Y=35310175500en_HK
dc.identifier.scopusauthoridPhillips, DL=7404519365en_HK

Export via OAI-PMH Interface in XML Formats


OR


Export to Other Non-XML Formats