title: Gas-Phase Infrared and NMR Investigation of the Conformers of Diacetone Diperoxide (DADP).
abstract: Gas-phase infrared measurements of diacetone diperoxide (DADP) indicate a chair conformation with less than 5% of the predicted twist conformer. Vibrational frequencies are very similar to those previously measured in the solid state. Solution NMR measurements using 2D exchange spectroscopy (EXSY) also set a very low maximum limit on the equilibrium population of the twist conformer, with a room-temperature free-energy difference in excess of 14.5 kJ/mol. These experimental results are in accord with high-level quantum calculations incorporating full thermochemistry and solvation effects, which indicate a free-energy difference in the range of 14.7-17.5 kJ/mol in polar solvents.
authors.affiliation: Department of Chemistry, University of Nebraska at Lincoln , Lincoln, Nebraska 68588-0304, United States.
authors.forename: Chunlei
authors.initials: C
authors.lastname: Guo
authors.affiliation: Department of Chemistry, University of Nebraska at Lincoln , Lincoln, Nebraska 68588-0304, United States.
authors.forename: John
authors.initials: J
authors.lastname: Persons
authors.affiliation: Department of Chemistry, Missouri Western State University , 4525 Downs Drive, St. Joseph, Missouri 64507, United States.
authors.forename: Jeffrey N
authors.initials: JN
authors.lastname: Woodford
authors.affiliation: Department of Chemistry, University of Nebraska at Lincoln , Lincoln, Nebraska 68588-0304, United States.
authors.forename: Gerard S
authors.initials: GS
authors.lastname: Harbison