查看文章

We investigate the perchlorate anion, ClO 4−, microhydrated with up to eight water molecules using infrared photodissociation (IRPD) spectroscopy aided by density functional theory computations. The features observed in the IRPD spectra of D 2-tagged ClO 4−(H 2 O) n with n= 0− 8 in the O–H stretching (2800–3800 cm− 1) and fingerprint (800–1800 cm− 1) spectral ranges are assigned to vibrational modes of the solvent, ie, free and hydrogen-bonded O–H stretching and H 2 O bending modes, and of the solute, ie, perchlorate stretching modes. The splitting of the triply degenerate antisymmetric stretching mode in the bare ClO 4−(1102 cm− 1) upon microhydration directly reports on the symmetry of the local solvation network, while the red-shift of the hydrogen-bonded O–H stretching bands in comparison to those of free O–H oscillators (> 3700 cm− 1) reflects the strength of the anion-water (3550–3650 cm− 1 …