title: Spectroscopic investigation of fluoroiodomethane, CH2FI: Fourier-transform microwave and millimeter-/submillimeter-wave spectroscopy and quantum-chemical calculations.
abstract: Guided by theoretical predictions, the rotational spectrum of fluoroiodomethane, CH(2)FI, has been recorded and assigned. Accurate values are reported for the ground-state rotational constants, all quartic, sextic, and two octic centrifugal-distortion constants. The hyperfine structure of the rotational spectrum was thoroughly investigated using a Fourier-transform microwave spectrometer and the Lamb-dip technique in the millimeter-/submillimeter-wave region, thus allowing the accurate determination of the complete iodine quadrupole-coupling tensor and of the diagonal elements of the iodine spin-rotation tensor. Relativistic effects turned out to be essential for the accurate theoretical prediction of the dipole moment and quadrupole-coupling constants and were accounted for by direct perturbation theory and a spin-free four-component treatment based on the Dirac-Coulomb Hamiltonian. The relativistic corrections to the dipole moment amount to up to 34% and to the iodine quadrupole-coupling tensor to about 15-16% of the total values.
authors.affiliation: Dipartimento di Chimica G. Ciamician, Università di Bologna, Bologna, Italy. cristina.puzzarini@unibo.it
authors.forename: Cristina
authors.initials: C
authors.lastname: Puzzarini
authors.forename: Gabriele
authors.initials: G
authors.lastname: Cazzoli
authors.forename: Juan Carlos
authors.initials: JC
authors.lastname: López
authors.forename: José Luis
authors.initials: JL
authors.lastname: Alonso
authors.forename: Agostino
authors.initials: A
authors.lastname: Baldacci
authors.forename: Alessandro
authors.initials: A
authors.lastname: Baldan
authors.forename: Stella
authors.initials: S
authors.lastname: Stopkowicz
authors.forename: Lan
authors.initials: L
authors.lastname: Cheng
authors.forename: Jürgen
authors.initials: J
authors.lastname: Gauss