Knowledge Bank

An electronic spectrum of the SiB molecule has been observed for the first time. The SiB molecule was produced in a Corona Excited Supersonic Expansion source using a mixture of diborane and silane gases seeded in helium. The emitted light was dispersed with a 1.3m spectrometer and recorded with a CCD camera. The region from 200nm to 800nm was examined and a single electronic system, A$4\Pi -X4\Sigma -$ observed with a 0-0 origin at 18432\wn . Supersonic cooling results in a rotational temperature of 20K and most emission is from the lowest $\Omega$=5/2 component. Observation of the $\Omega$=3/2 component gives the spin-orbit splitting as -23.9 \wn . The 0-0, 0-1, 0-2, 1-0, 1-2, and 1-3 bands have been analyzed.