Knowledge Bank

The infrared spectra of N$\mathrm{<mrow\; data-mjx-texclass="ORD">2</mrow>}$-H$\mathrm{<mrow\; data-mjx-texclass="ORD">2</mrow>}$O, O$\mathrm{<mrow\; data-mjx-texclass="ORD">2</mrow>}$-H$\mathrm{<mrow\; data-mjx-texclass="ORD">2</mrow>}$O and Ar-H$\mathrm{<mrow\; data-mjx-texclass="ORD">2</mrow>}$O complexes in superfluid He droplets were measured in the range of the stretching vibrational bands of water molecules. The infrared intensity of the anti-symmetric stretching bands in these complexes were found to be very similar to that in single H$\mathrm{<mrow\; data-mjx-texclass="ORD">2</mrow>}$O molecules. The spectra show that H$\mathrm{<mrow\; data-mjx-texclass="ORD">2</mrow>}$O in O$\mathrm{<mrow\; data-mjx-texclass="ORD">2</mrow>}$-H$\mathrm{<mrow\; data-mjx-texclass="ORD">2</mrow>}$O and Ar-H$\mathrm{<mrow\; data-mjx-texclass="ORD">2</mrow>}$O rotates nearly freely, whereas no indication of H$\mathrm{<mrow\; data-mjx-texclass="ORD">2</mrow>}$O internal rotation was observed in N$\mathrm{<mrow\; data-mjx-texclass="ORD">2</mrow>}$-H$\mathrm{<mrow\; data-mjx-texclass="ORD">2</mrow>}$O spectra. The conformation of the N$\mathrm{<mrow\; data-mjx-texclass="ORD">2</mrow>}$-H$\mathrm{<mrow\; data-mjx-texclass="ORD">2</mrow>}$O complexes was estimated from the rotational constants.