Open AccessThe structures of cyclic dihydronium cations
Author(s) -
Sonjae Wallace,
Lulu Huang,
Lou Massa,
Utpal Mukhopadhyay,
Ivan Bernal,
Jerome Karle
Publication year - 2007
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.011
H-Index - 771
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.0708249104
Subject(s) - hydronium , crystal structure , crystallography , ion , crystal (programming language) , density functional theory , chemistry , phase (matter) , binding energy , computational chemistry , chemical physics , atomic physics , physics , organic chemistry , computer science , programming language
Recent experimental discoveries have revealed the existence of hitherto unexpected cyclic hydronium di-cations trapped within crystal structures. The molecular formulas are (H14 O6 )2+ , present as two isomers, four- and six-member cyclic structures, and (H18 O8 )2+ , an eight-member cyclic structure. As these unprecedented hydronium species are stabilized by the crystal structures in which they are captured, the question arises whether they could be stable as independent species as, for example, in solution or gas phase. Quantum mechanical density functional theory calculations are used to investigate this question. We find these doubly charged cyclic hydronium structures to be energetically stable and, as between the four- and six-member structures, the former has more binding energy than the latter. We also determine the theoretically optimized structures for all three ions and give their calculated atomic charges for both their crystal and optimized geometries.