Revisiting IR spectra of H2S in argon matrix: Identification and assignment of monomer to tetramer

An extensive spectral assignment of the 𝝂𝑺-𝑯 bands of H2S clusters up to tetramer in argon matrix have been carried out. Spectral bands within 2615-2651 cm-1 spectral range, which has hitherto been accepted as vibration-rotation transitions, have been assigned to clusters of different sizes along with 𝝂𝟏 and 𝝂𝟑 bands of monomer. Spectral shifts have been found to increase monotonically with size of cyclic clusters confirming cooperative nature of S–H‧‧‧S H-bond.