Making very short O–H···Ph hydrogen bonds: the example of tetraphenylborate salts

Abstract

In crystal structures of tetraphenylborate salts with cationic X–OH donors (choline, triethanolammonium dihydrate, 6-ammonio-n-hexanoic acid monohydrate), the shortest intermolecular O–H···Ph hydrogen bonds known as yet have been found, both in terms of the H···M as well as the O···M distances (2.17 and 3.07 Å, respectively, for normalized O–H distance; M = midpoint of the aromatic ring). In these interactions the donor H and O atoms reside roughly over the centroids of the acceptor groups. A supporting database study of very short O–H···Ph hydrogen bonds has also been made (using the Cambridge Structural Database).