Laser spectroscopy of iridium monoboride

Abstract

High resolution laser induced fluorescence spectrum of IrB in the spectral region between 545 and 610 nm has been recorded and analyzed. Reacting laser-ablated iridium atoms with 1% B2 H6 seeded in argon produced the IrB molecule. This is the first experimental observation of the IrB molecule. Four vibronic transition bands, (v,0) with v=0-3 of an electronic transition system, have been observed. Spectra of all four isotopic molecules, Ir191 B10, Ir193 B10, Ir191 B11, and Ir193 B11, were recorded. Isotopic relationships confirmed the carrier of the spectra and the vibrational quantum number assignment. Preliminary analysis of rotational lines showed that these vibronic bands are with ′ =2 and ″ =3. The electronic transition identified is assigned as the [16.5] Π23 -X Δ33 system. Partially resolved hyperfine structure which conforms to the Hund's case aΒ coupling scheme has been observed and analyzed. The bond length r0 of the lower X Δ33 state of IrB was determined to be 1.7675 Å. © 2008 American Institute of Physics.