Hyperfine interactions in the A3Φ4 and X3Φ4 states of iridium monofluoride, IrF.

Laser induced-fluorescence spectra of the 1-0 band of the A(3)Φ(4)-X(3)Φ(4) transition of iridium monofluoride, IrF, have been obtained at near natural linewidth resolution using supersonic molecular beam techniques. The spectra show a complex, clearly resolved hyperfine structure which has significant contributions from the magnetic and quadrupole hyperfine terms in (193)Ir and (191)Ir, both with I = 3/2, and the fluorine magnetic hyperfine term (I = 1∕2). The spectra of both (193)IrF and (191)IrF isotopologues have been assigned and analyzed. The hyperfine structure was interpreted with the aid of atomic hyperfine parameters, which were used to determine the configurational composition of the ground state and to estimate the individual molecular hyperfine parameters.