Cooperative Strong Charge Assisted N-H---O Hydrogen Bonding and Weaker Nonconventional C-H---N Hydrogen Bonding in the Formation of Extended Hydrogen Bonded Networks with 2,3,5,6-tetrafuorobenzoic acid
Cooperative strong charge-assisted hydrogen bonding and weaker nonconventional hydrogen bonding are probed through cocrystals formed between 2,3,5,6-tetrafluorobenzoic acid and three 2-aminopyrazines. In each of these cocrystals, cooperative nonconventional hydrogen bonding and charge-assisted hydrogen bonding results in the formation of hydrogen-bonded supramolecular networks. A charge-assisted cyclic hydrogen bonded motif, R22(8), is formed between the 2-aminopyrazinium cation and the carboxylate anion along with a nonconventional C-H···N hydrogen bond between the phenyl hydrogen and second ring N in the pyrazine. Secondary hydrogen bonding interactions result in the formation of a double-stranded linear polymer, a planar 2D polymer, or an interconnected 3D network depending on secondary substitution of the 2-aminopyrazine. The related formation of both 1:1 and 2:1 cocrystals between 4-pyrrolidinopyridine and 2,3,5,6-tetrafluorobenzoic acid is also reported.
Bosch, Eric, and Nathan P. Bowling. "Cooperative Strong Charge-Assisted N–H··· O Hydrogen Bonding and Weaker Nonconventional C–H··· N Hydrogen Bonding in the Formation of Extended Hydrogen-Bonded Networks with 2, 3, 5, 6-Tetrafluorobenzoic Acid." Crystal Growth & Design 20, no. 3 (2020): 1565-1571.
Crystal Growth and Design