Knowledge Bank

The infrared spectrum of cyclic $H2B2O3(g)$ has been obtained from $4000cm-1$ to $250cm-1$. A number of isotopic species, including $H2B216O3,H2B218O3,D2B216O3$, and $H210B216O3$ were prepared by reacting the appropriate isotopic combinations of oxygen with boroxine $(H3B3O3)$. The spectra are interpreted on the basis of a planar molecule with $C2v$ symmetry as demonstrated in microwave $studies.1$ Bands due to the mixed isotopic species $HDB216O\ast \ast \ast$ and $H210B11B16O3$ have, also, been assigned, including some bands interpreted as out-of-plane vibrations not active in the ``pure'' isotopic molecules.