title: Anions Stabilize Each Other inside Macrocyclic Hosts.
abstract: Contrary to the simple expectations from Coulomb's law, Weinhold proposed that anions can stabilize each other as metastable dimers, yet experimental evidence for these species and their mutual stabilization is missing. We show that two bisulfate anions can form such dimers, which stabilize each other with self-complementary hydrogen bonds, by encapsulation inside a pair of cyanostar macrocycles. The resulting 2:2 complex of the bisulfate homodimer persists across all states of matter, including in solution. The bisulfate dimer's OH⋅⋅⋅O hydrogen bonding is seen in a1H NMR peak at 13.75 ppm, which is consistent with borderline-strong hydrogen bonds.
authors.affiliation: Dept. of Chemistry, Indiana University Bloomington, 800 E. Kirkwood Ave., Bloomington, IN, 47405, USA.
authors.forename: Elisabeth M
authors.initials: EM
authors.lastname: Fatila
authors.affiliation: Dept. of Chemistry, Indiana University Bloomington, 800 E. Kirkwood Ave., Bloomington, IN, 47405, USA.
authors.forename: Eric B
authors.initials: EB
authors.lastname: Twum
authors.affiliation: Dept. of Chemistry, Indiana University Bloomington, 800 E. Kirkwood Ave., Bloomington, IN, 47405, USA.
authors.forename: Arkajyoti
authors.initials: A
authors.lastname: Sengupta
authors.affiliation: Dept. of Chemistry, Indiana University Bloomington, 800 E. Kirkwood Ave., Bloomington, IN, 47405, USA.
authors.forename: Maren
authors.initials: M
authors.lastname: Pink
authors.affiliation: Dept. of Chemistry, Indiana University Bloomington, 800 E. Kirkwood Ave., Bloomington, IN, 47405, USA.
authors.forename: Jonathan A
authors.initials: JA
authors.lastname: Karty
authors.affiliation: Dept. of Chemistry, Indiana University Bloomington, 800 E. Kirkwood Ave., Bloomington, IN, 47405, USA.
authors.forename: Krishnan
authors.initials: K
authors.lastname: Raghavachari
authors.affiliation: Dept. of Chemistry, Indiana University Bloomington, 800 E. Kirkwood Ave., Bloomington, IN, 47405, USA. aflood@indiana.edu.
authors.forename: Amar H
authors.identifier: 0000-0002-2764-9155
authors.initials: AH
authors.lastname: Flood
keywords: anion recognition; bisulfates; hydrogen bonding; macrocycles; supramolecular chemistry