FTIR spectra of (HF)n species in solid neon

Condensation of Ne/HF mixtures at 5 K produces in addition to monomer HF numerous strong, sharp infrared absorptions in the 4000–3600 and 600–300 cm−1 regions and broader bands in the 3500–3100 and 1300–600 cm−1 regions. The relative absorbances of these bands depend upon concentration, spray-on rate, and sample annealing, which are used to identify individual (HF)n species. Sharp bands at 3919, 3848, and 410 cm−1 are assigned to (HF)2. Further infrared evidence is presented for an open chain (HF)3 species. The broader bands assigned to cyclic-(HF)n species increase at the expense of the sharper bands under conditions which favor association of HF in the matrix.