Sulfate ion patterns water at long distance.
The chemical origins of the Hofmeister series are investigated using infrared photodissociation (IRPD) spectroscopy. IRPD spectra of SO(4)(2-)(H(2)O)(n) with up to 80 water molecules have a band at approximately 3710 cm(-1) for n > 43 but not for n < or = 43. This band corresponds to outer-shell water molecules with "free" OH groups similar to those at the surface of bulk water. These results indicate that the sulfate dianion has a long-range effect on water structure, and this effect is likely to be an important factor in its Hofmeister behavior.
O'Brien
Jeremy T
JT
Department of Chemistry, University of California, Berkeley, California 94720-1460, USA.
Prell
James S
JS
Bush
Matthew F
MF
Williams
Evan R
ER
D013055:Spectrophotometry, Infrared; D013431:Sulfates / Q000737:chemistry*; D013696:Temperature; D014867:Water / Q000737:chemistry*
D013431:Sulfates; D014867:Water