Intramolecular structure and dynamics of mequinol and guaiacol in the gas phase: Rotationally resolved electronic spectra of their S1 states.
The molecular structures of guaiacol (2-methoxyphenol) and mequinol (4-methoxyphenol) have been studied using high resolution electronic spectroscopy in a molecular beam and contrasted with ab initio computations. Mequinol exhibits two low frequency bands that have been assigned to electronic origins of two possible conformers of the molecule, trans and cis. Guaiacol also shows low frequency bands, but in this case, the bands have been assigned to the electronic origin and vibrational modes of a single conformer of the isolated molecule. A detailed study of these bands indicates that guaiacol has a vibrationally averaged planar structure in the ground state, but it is distorted along both in-plane and out-of-plane coordinates in the first electronically excited state. An intramolecular hydrogen bond involving the adjacent   -OH and   -OCH3 groups plays a major role in these dynamics.
División de Ciencias e Ingenierías, Universidad de Guanajuato-Campus León, León, Guanajuato 37150, Mexico.
José Arturo
JA
Ruiz-Santoyo
División de Ciencias e Ingenierías, Universidad de Guanajuato-Campus León, León, Guanajuato 37150, Mexico.
Marcela
M
Rodríguez-Matus
Departamento de Física Aplicada, Centro de Investigación y de Estudios Avanzados Unidad Mérida, Mérida, Yucatán 97310, Mexico.
José Luis
JL
Cabellos
Department of Chemistry, Winston-Salem State University, Winston-Salem, North Carolina 27110, USA.
John T
JT
Yi
Department of Chemistry, University of Vermont, Burlington, Vermont 05405, USA.
David W
DW
Pratt
Physikalische Chemie, Heinrich-Heine-Universität, Düsseldorf, Deutschland 40204, Germany.
Michael
M
Schmitt
Departamento de Física Aplicada, Centro de Investigación y de Estudios Avanzados Unidad Mérida, Mérida, Yucatán 97310, Mexico.
Gabriel
G
Merino
División de Ciencias e Ingenierías, Universidad de Guanajuato-Campus León, León, Guanajuato 37150, Mexico.
Leonardo
L
Álvarez-Valtierra