Simple ortho-para hydrogen and para-ortho deuterium converter for matrix isolation spectroscopy

A copper tube containing catalyst immersed in the cold gas above liquid helium is used to convert normal H2 and D2 to high purity J=0 samples. The converted samples are sublimed directly from 12–16 K catalyst to the 4 K matrix substrate for recording infrared spectra. The decrease of infrared absorptions due to J=1 isomer perturbations on the major J=0 species bands show that solid samples >99% in the J=0 species are formed. Such high purity p-H2 and o-D2 subjected to Tesla coil discharge during condensation at 4 K sustain a 2%–8% decrease in the J=0 species population depending on the discharge pressure. We also show that orthodeuterium is an excellent matrix host.