Article: Reaction mechanisms and structural characterization of the reactive intermediates observed after the photolysis of 3-(hydroxymethyl)benzophenone in acetonitrile, 2-propanol, and neutral and acidic aqueous solutions
| Title | Reaction mechanisms and structural characterization of the reactive intermediates observed after the photolysis of 3-(hydroxymethyl)benzophenone in acetonitrile, 2-propanol, and neutral and acidic aqueous solutions | ||||||||||||
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| Authors | Ma, J1 Li, MD1 Phillips, DL1 Wan, P2 | ||||||||||||
| Keywords | Aqueous solutions Density functional theory Triplet state Photoinduced reaction Raman spectrometry | ||||||||||||
| Issue Date | 2011 | ||||||||||||
| Publisher | American Chemical Society. The Journal's web site is located at http://pubs.acs.org/joc | ||||||||||||
| Citation | Journal Of Organic Chemistry, 2011, v. 76 n. 10, p. 3710-3719 [How to Cite?] DOI: http://dx.doi.org/10.1021/jo1024249 | ||||||||||||
| Abstract | Nanosecond time-resolved resonance Raman (ns-TR3) spectroscopy was employed to investigate the photoinduced reactions of 3-(hydroxymethyl) benzophenone (1) in acetonitrile, 2-propanol, and neutral and acidic aqueous solutions. Density functional theory calculations were utilized to help the interpretation of the experimental spectra. In acetonitrile, the neutral triplet state 1 [denoted here as (m-BPOH)3] was observed on the nanosecond to microsecond time scale. In 2-propanol this triplet state appeared to abstract a hydrogen atom from the solvent molecules to produce the aryphenyl ketyl radical of 1 (denoted here as ArPK of 1), and then this species underwent a cross-coupling reaction with the dimethylketyl radical (also formed from the hydrogen abstraction reaction) to form a long-lived light absorbing transient species that was tentatively identified to be mainly 2-(4-(hydroxy(3- (hydroxymethyl)phenyl)methylene)cyclohexa-2,5-dienyl)propan-2-ol. In 1:1 H 2O:CH3CN aqueous solution at neutral pH, (m-BPOH) 3 reacted with water to produce the ArPK of 1 and then underwent further reaction to produce a long-lived light absorbing transient species. Three photochemical reactions appeared to take place after 266 nm photolysis of 1 in acidic aqueous solutions, a photoreduction reaction, an overall photohydration reaction, and a novel photoredox reaction. TR3 experiments in 1:1 H2O:CH3CN aqueous solution at pH 2 detected a new triplet biradical species, which is associated with an unusual photoredox reaction. This reaction is observed to be the predominant reaction at pH 2 and seems to face competition from the overall photohydration reaction at pH 0. © 2011 American Chemical Society. | ||||||||||||
| ISSN | 0022-3263 2011 Impact Factor: 4.45 2011 SCImago Journal Rankings: 0.351 | ||||||||||||
| DOI | http://dx.doi.org/10.1021/jo1024249 | ||||||||||||
| ISI Accession Number ID | WOS:000290465700011
Funding Information: The research was supported by grants from the Research Grants Council of Hong Kong (HKU 7035/08P) to D.L.P. D.L. P. thanks the Croucher Foundation for the Award of a Senior Research Fellowship and the University of Hong Kong for the Outstanding Researcher Award. Support from the University Grants Committee Areas of Excellence Scheme (AoE/P-03/08) and the Special Equipment Grant (SEG HKU/07) is also gratefully acknowledged. | ||||||||||||
| References | References in Scopus | ||||||||||||
| Grants | Institute of Molecular Functional Materials |
| dc.contributor.author | Ma, J | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| dc.contributor.author | Li, MD | ||||||||||||
| dc.contributor.author | Phillips, DL | ||||||||||||
| dc.contributor.author | Wan, P | ||||||||||||
| dc.date.accessioned | 2011-09-23T05:43:39Z | ||||||||||||
| dc.date.available | 2011-09-23T05:43:39Z | ||||||||||||
| dc.date.issued | 2011 | ||||||||||||
| dc.description.abstract | Nanosecond time-resolved resonance Raman (ns-TR3) spectroscopy was employed to investigate the photoinduced reactions of 3-(hydroxymethyl) benzophenone (1) in acetonitrile, 2-propanol, and neutral and acidic aqueous solutions. Density functional theory calculations were utilized to help the interpretation of the experimental spectra. In acetonitrile, the neutral triplet state 1 [denoted here as (m-BPOH)3] was observed on the nanosecond to microsecond time scale. In 2-propanol this triplet state appeared to abstract a hydrogen atom from the solvent molecules to produce the aryphenyl ketyl radical of 1 (denoted here as ArPK of 1), and then this species underwent a cross-coupling reaction with the dimethylketyl radical (also formed from the hydrogen abstraction reaction) to form a long-lived light absorbing transient species that was tentatively identified to be mainly 2-(4-(hydroxy(3- (hydroxymethyl)phenyl)methylene)cyclohexa-2,5-dienyl)propan-2-ol. In 1:1 H 2O:CH3CN aqueous solution at neutral pH, (m-BPOH) 3 reacted with water to produce the ArPK of 1 and then underwent further reaction to produce a long-lived light absorbing transient species. Three photochemical reactions appeared to take place after 266 nm photolysis of 1 in acidic aqueous solutions, a photoreduction reaction, an overall photohydration reaction, and a novel photoredox reaction. TR3 experiments in 1:1 H2O:CH3CN aqueous solution at pH 2 detected a new triplet biradical species, which is associated with an unusual photoredox reaction. This reaction is observed to be the predominant reaction at pH 2 and seems to face competition from the overall photohydration reaction at pH 0. © 2011 American Chemical Society. | ||||||||||||
| dc.description.grant | Institute of Molecular Functional Materials | ||||||||||||
| dc.description.grantcode | 101180 | ||||||||||||
| dc.description.nature | Link_to_subscribed_fulltext | ||||||||||||
| dc.identifier.citation | Journal Of Organic Chemistry, 2011, v. 76 n. 10, p. 3710-3719 [How to Cite?] DOI: http://dx.doi.org/10.1021/jo1024249 | ||||||||||||
| dc.identifier.doi | http://dx.doi.org/10.1021/jo1024249 | ||||||||||||
| dc.identifier.epage | 3719 | ||||||||||||
| dc.identifier.hkuros | 194539 | ||||||||||||
| dc.identifier.isi | WOS:000290465700011
Funding Information: The research was supported by grants from the Research Grants Council of Hong Kong (HKU 7035/08P) to D.L.P. D.L. P. thanks the Croucher Foundation for the Award of a Senior Research Fellowship and the University of Hong Kong for the Outstanding Researcher Award. Support from the University Grants Committee Areas of Excellence Scheme (AoE/P-03/08) and the Special Equipment Grant (SEG HKU/07) is also gratefully acknowledged. | ||||||||||||
| dc.identifier.issn | 0022-3263 2011 Impact Factor: 4.45 2011 SCImago Journal Rankings: 0.351 | ||||||||||||
| dc.identifier.issue | 10 | ||||||||||||
| dc.identifier.pmid | 21466158 | ||||||||||||
| dc.identifier.scopus | eid_2-s2.0-79956135687 | ||||||||||||
| dc.identifier.spage | 3710 | ||||||||||||
| dc.identifier.uri | http://hdl.handle.net/10722/138985 | ||||||||||||
| dc.identifier.volume | 76 | ||||||||||||
| dc.language | eng | ||||||||||||
| dc.publisher | American Chemical Society. The Journal's web site is located at http://pubs.acs.org/joc | ||||||||||||
| dc.publisher.place | United States | ||||||||||||
| dc.relation.ispartof | Journal of Organic Chemistry | ||||||||||||
| dc.relation.references | References in Scopus | ||||||||||||
| dc.subject | Aqueous solutions | ||||||||||||
| dc.subject | Density functional theory | ||||||||||||
| dc.subject | Triplet state | ||||||||||||
| dc.subject | Photoinduced reaction | ||||||||||||
| dc.subject | Raman spectrometry | ||||||||||||
| dc.title | Reaction mechanisms and structural characterization of the reactive intermediates observed after the photolysis of 3-(hydroxymethyl)benzophenone in acetonitrile, 2-propanol, and neutral and acidic aqueous solutions | ||||||||||||
| dc.type | Article |
Author Affiliations
- The University of Hong Kong
- University of Victoria