Two different conformations of the triplet state of alkyl phenylglyoxylates were observed by means of time-resolved step-scan FT-IR spectroscopy. The amplitude of the peak corresponding to the sterically hindered conformation decreases as the size of the alkyl group increases. Both conformations exhibit similar reactivity in intermolecular hydrogen abstraction, but only one of them undergoes Norrish Type II photoelimination.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1021/ja0282792 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Carbon-13 Hyperpolarization of α-Ketocarboxylates with Parahydrogen in Reversible Exchange.
ChemMedChem
October 2024
Department of Chemistry, North Carolina State University, 2620 Yarbrough Dr., Raleigh, NC, 27695, USA.
Signal Amplification by Reversible Exchange (SABRE) is a relatively simple and fast hyperpolarization technique that has been used to hyperpolarize the α-ketocarboxylate pyruvate, a central metabolite and the leading hyperpolarized MRI contrast agent. In this work, we show that SABRE can readily be extended to hyperpolarize C nuclei at natural abundance on many other α-ketocarboxylates. Hyperpolarization is observed and optimized on pyruvate (P=17 %) and 2-oxobutyrate (P=25 %) with alkyl chains in the R-group, oxaloacetate (P=11 %) and alpha-ketoglutarate (P=13 %) with carboxylate moieties in the R group, and phenylpyruvate (P=2 %) and phenylglyoxylate (P=2 %) with phenyl rings in the R-group.
View Article and Find Full Text PDFAnalysis of the time-resolved FTIR spectra produced by the photolysis of alkyl phenylglyoxylates.
Photochem Photobiol Sci
June 2007
Center for Photochemical Sciences, Bowling Green State University, Bowling Green, OH 43403, USA.
The photochemistry of alkyl phenylglyoxylates (APG) was further investigated using time-resolved infrared spectroscopy. The primary focus was on the analysis of weak transient bands around 1828 and 1730 cm(-1) in the time-resolved FTIR spectra of glyoxylates. The observed transients were assigned to benzoyl and alkyl mandelate ester radicals, respectively.
View Article and Find Full Text PDFObservation of the two triplet state conformations of alkyl phenylglyoxylates.
Photochem Photobiol Sci
September 2004
Center for Photochemical Sciences, Bowling Green State University, Bowling Green, OH 43403, USA.
Step-scan time-resolved FT-IR spectra of alkyl phenylglyoxylates in hexane with a 4 cm(-1) spectral resolution reveal splitting of the transient absorption signal near 1650 cm(-1) into two closely located peaks with different lifetimes on the nanosecond time scale. This signal had been previously assigned to the triplet state of the starting material that gives rise to the alpha-hydroxyphenylketene. In the current article, evidence is presented to assign these two peaks to different triplet state conformers only one of which undergoes fast Norrish Type II photoelimination.
View Article and Find Full Text PDFObservations of different triplet conformations in time-resolved infrared spectra of alkyl phenylglyoxylates.
J Am Chem Soc
December 2002
Center for Photochemical Sciences, Bowling Green State University, Bowling Green, Ohio 43403, USA.
Two different conformations of the triplet state of alkyl phenylglyoxylates were observed by means of time-resolved step-scan FT-IR spectroscopy. The amplitude of the peak corresponding to the sterically hindered conformation decreases as the size of the alkyl group increases. Both conformations exhibit similar reactivity in intermolecular hydrogen abstraction, but only one of them undergoes Norrish Type II photoelimination.
View Article and Find Full Text PDFTime-resolved step-scan fourier transform infrared spectroscopy of alkyl phenylglyoxylates.
J Am Chem Soc
May 2001
Center for Photochemical Sciences, Bowling Green State University, Bowling Green, Ohio 43403, USA.
Want AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!