Rotationally Resolved Electronic Spectra of the B-X Transition in Multiple Conformers of 1-Butoxy and 1-Pentoxy Radicals

摘要

We report the rotational analyses of six bands of the B-X electronic transition of jet-cooled 1-butoxy radical and 11 bands of the corresponding transition in 1-pentoxy radical. From these spectra, we have obtained experimental values for the rotational and spin-rotational constants in the X state and the rotational constants, vibrational frequencies, and band origins in the B state. By comparing the rotational and spin -rotational constants from these analyses with corresponding values from quantum chemistry computations, we assign the observed spectra to the electronic origins and excited vibrational levels of the B state of three distinct conformers of 1-butoxy and five distinct conformers of 1-pentoxy. These assigned bands can be used as unambiguous diagnostics of the radical species, its structural isomer, and its conformation.These data can be used to identify, and to some extent rationalize, distinctively different conformer stabilities in the X and B states and conformer-dependent dynamical behavior.