Time resolved spectroscopy of water in the infrared: New data and discussion

We demonstrate sub-picosecond spectroscopy of an isotopic water mixture presenting strong evidence for four major spectral components within the OH-band of HDO in the solvent D₂O peaked at approximately 3330 cm^-1 (I), 3390 cm^-1 (II), 3460 cm^-1 (III), and 3520 cm^-1 (IV). Species I and IV are proposed to give rise for discrete components with local hexagone and weakly bound structures, respectively. The remaining species are most probably related to combination tones with hydrogen bridge bond vibrations. Furthermore we summarise the findings on the vibrational and spectral dynamics of water as determined by time-resolved IR-spectroscopy of HDO molecules dissolved at low concentration in D₂O.