Theoretical prediction of spectroscopic constants of 1-alkoxy radicals

Spectroscopic constants for the conformers of the 1-alkoxy radicals were computed by ab initio and density functional methods. These parameters include ground and excited state rotational constants, harmonic frequencies, and and excitation energies. Elements of the electronic spin–molecular rotation tensor have also been predicted for the ground electronic state utilizing a simple transformation. The transformation employed the experimentally observed spin-rotation tensor of the ethoxy radical as a reference and the calculated rotational constants of the ethoxy radical and the investigated 1-alkoxy radicals. The predicted spectroscopic parameters are in good agreement with the experimental ones where available, and found to be useful parameters for assigning the rotationally resolved spectral bands to given conformers.