Please use this identifier to cite or link to this item:
Title: Photophysics and photodeprotection reactions of p-Methoxyphenacyl Phototriggers : an ultrafast and nanosecond time-resolved spectroscopic and density functional theory study
Authors: An, HY
Kwok, WM 
Ma, C
Guan, X
Kan, JTW
Toy, PH
Phillips, DL
Issue Date: 2010
Publisher: American Chemical Society
Source: Journal of organic chemistry, 2010, v. 75, no. 17, p. 5837-5851 How to cite?
Journal: Journal of organic chemistry 
Abstract: Time-resolved spectroscopic experiments were performed to investigate the kinetics and mechanisms of the photodeprotection reactions for p-methoxyphenacyl (pMP) compounds, p-methoxyphenacyl diethyl phosphate (MPEP) and diphenyl phosphate (MPPP). The experimental results reveal that compared to the previous reports for the counterpart p-hydroxyphenacyl (pHP) phosphates, the (3)n pi*/pi pi* mixed character triplet of pMP acts as a reactive precursor that leads to the subsequent solvent and leaving group dependent chemical reactions and further affects the formation of photoproducts. The MPPP triplet in H(2)O/CH(3)CN and in fluorinated alcohols shows a rapid heterolytic cleavage (tau approximate to 5.4 ns) that results in deprotection and formation of a solvolytic rearrangement product, whereas the MPPP triplet in CH(3)CN and the MPEP triplet in CH(3)CN and H(2)O/CH(3)CN and fluorinated alcohols decay on a much longer time scale (tau approximate to 100 ns) with little observation of the rearrangement product. The density functional theory (DFT) calculations reveal a substantial solvation effect that is connected with the methoxy versus hydroxyl substitution in accounting for the different deprotection reactivity of pMP and pHP compounds. The results reported here provide new insight in elucidating the solvent and leaving group dependent dual reactivity of pMP compounds on the formation of the rearrangement versus reductive photoproduct.
ISSN: 0022-3263
EISSN: 1520-6904
DOI: 10.1021/jo100848b
Appears in Collections:Journal/Magazine Article

View full-text via PolyU eLinks SFX Query
Show full item record


Last Week
Last month
Citations as of Jul 28, 2018


Last Week
Last month
Citations as of Aug 9, 2018

Page view(s)

Last Week
Last month
Citations as of Aug 13, 2018

Google ScholarTM



Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.