A New Band System of Tin Oxide

A new band system of SnO with origin at 36,803 ${\mathrm{cm}}^{-1\mathrm{}}$ has been observed in an arc at reduced pressures. The lower state of this system is identical with that of the known $A$ and $B$ systems. The upper state is new and has a vibrational frequency, ${\omega }_e=497.8\mathrm{}$ ${\mathrm{cm}}^{-1\mathrm{}}$. The complexity of the isotope effect prevents rotational analysis.