biostudies-literatureStoyanov ESNIGMS NIH HHS1484-5https://www.ebi.ac.uk/biostudies/studies/S-EPMC2946644biostudies-literatureUnknown132(5)The hydrogen ion in water, H(aq)(+), is a unique H(13)O(6)(+) entity that defines the boundary of positive-charge delocalization. Its central unit is neither a C(3v) H(3)O(+) Eigen-type ion nor a typical H(5)O(2)(+) Zundel-type ion. IR spectroscopy indicates that the H(13)O(6)(+) ion has an unexpectedly long central O...O separation (>>2.43 A), showing that in comparison with the gas and solid phases, the environment of liquid water is uniquely proficient in delocalizing positive charge. These results will change the description of H(aq)(+) in textbooks of chemistry, and a more extensive delocalization of positive charge may need to be incorporated into descriptions of mechanisms of aqueous proton transport.Journal of the American Chemical SocietyThe structure of the hydrogen ion (H(aq)+) in water.PMC2946644R01 GM023851-29GM023851R01 GM023851Stoyanov ESStoyanova IVReed CAfalseThe structure of the hydrogen ion (H(aq)+) in water.The hydrogen ion in water, H(aq)(+), is a unique H(13)O(6)(+) entity that defines the boundary of positive-charge delocalization. Its central unit is neither a C(3v) H(3)O(+) Eigen-type ion nor a typical H(5)O(2)(+) Zundel-type ion. IR spectroscopy indicates that the H(13)O(6)(+) ion has an unexpectedly long central O...O separation (>>2.43 A), showing that in comparison with the gas and solid phases, the environment of liquid water is uniquely proficient in delocalizing positive charge. These results will change the description of H(aq)(+) in textbooks of chemistry, and a more extensive delocalization of positive charge may need to be incorporated into descriptions of mechanisms of aqueous proton transport.2010-01-01T00:00:00Z2010 Feb2025-06-01T01:39:58.722Z2025-06-01T01:39:58.722ZS-EPMC29466442007805810.1021/ja9101826