Premium
Time‐resolved IR studies of α‐lactones
Author(s) -
Showalter Brett M.,
Toscano John P.
Publication year - 2004
Publication title -
journal of physical organic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.325
H-Index - 66
eISSN - 1099-1395
pISSN - 0894-3230
DOI - 10.1002/poc.789
Subject(s) - chemistry , nucleophile , carbene , ring (chemistry) , photochemistry , nanosecond , reaction rate constant , infrared spectroscopy , solvent , infrared , carbon dioxide , computational chemistry , medicinal chemistry , organic chemistry , kinetics , catalysis , laser , physics , quantum mechanics , optics
A series of α‐lactones were generated from the reaction of phenylchlorocarbene, 4‐nitrophenylchlorocarbene, diphenylcarbene, bis(4‐nitrophenyl)carbene and bis(4‐methoxyphenyl)carbene with carbon dioxide and examined by nanosecond time‐resolved infrared (TRIR) spectroscopy. Estimated second‐order rate constants for the reaction of these carbenes with carbon dioxide indicate that more nucleophilic carbenes react at faster rates, in agreement with previous low‐temperature matrix experiments. Spectral TRIR data confirms that the structure of α‐lactones is dependent both on substituents at the α‐carbon and on solvent polarity, with electron‐donating substituents and polar solvents favoring a zwitterionic ring‐opened structure as opposed to the three‐membered ring oxiranone form. B3LYP calculations using self‐consistent reaction field (SCRF) methods also provide support for these experimental investigations. Copyright © 2004 John Wiley & Sons, Ltd.