Bismuthine BiH3: Fact or Fiction? High-Resolution Infrared, Millimeter-Wave, and Ab Initio Studies

High resolution infrared spectra of the ν1–ν4 bands of BiH3, and ab initio calculations of the spectroscopic parameters

“…Less work has been done on (strongly) interacting states. Since BiH 3 is closer to the spherical top limit than any other of the previously investigated tops with C 3v symmetry [2], ambiguities due to redundancy occur here with particular strength.…”

“…Bismuthine BiH 3 , which is a highly reactive, shortlived species rapidly decomposing above )35°C to give Bi (deposited on all surfaces) and H 2 , was prepared as described in [1] and [2]. Since no multipass cell could be employed owing to the immediate deposition of black Bi on the metal-coated mirrors, spectra were studied using a double-jacketed glass cell of 1.2 m length with NaCl windows and external cooling.…”

“…Our initial communication [2] contained a brief comparison of the measured data with the best theoretical predictions then available, and the agreement between experiment and theory served as a strong argument to confirm the detection of BiH 3 and to support the experimental assignments. This theoretical work has now been extended and improved in a systematic manner using a variety of correlation treatments, basis sets, and pseudopotentials, partly in combination with core polarization potentials and counterpoise corrections [9].…”

“…We have recently been able to make enough BiH 3 , to study its spectra [2] and to determine its effective and equilibrium structures [3]. The HBiH bond angle, 90.32° [3], was found to be indeed very close to 90°, and accordingly the calculated sphericity parameter, c ¼ À0:015, is much closer to zero than for any other pyramidal symmetric top molecule.…”

“…Following the preliminary study [2] we now give a full account of the infrared (IR) spectrum of BiH 3 studied with high resolution, 5.5 Â 10 À3 cm À1 (m 1 ,m 3 ) and 6.6 Â 10 À3 cm À1 (m 2 , m 4 , respectively). Moreover, the rovibrational analysis of these spectra will be presented.…”