N,N,N′,N′,N′′-Pentamethyl-N′′-[2-(trimethylazaniumyl)ethyl]guanidinium bis(tetraphenylborate) acetone monosolvate

Abstract

The asymmetric unit of the title solvated salt, C11H28N42+·2C24H20B−·C3H6O, comprises two cations, four tetraphenylborate anions and two acetone molecules. One cation shows an orientational disorder at the CN3moiety and two sets of N-atom positions were found related by a 60° rotation, with a refined occupancy ratio of 0.935 (1):0.065 (1). The respective nitrogen-bonded –CH2and –CH3groups are included in the disorder model. The C—N bond lengths in the central CN3units of both guanidinium ions range between 1.3329 (17) and 1.364 (16) Å, indicating a degree of double-bond character. The central C atom is bonded to the three N atoms in a nearly ideal trigonal–planar geometry and one positive charge is delocalized in the CN3plane. The C—N bond lengths in the terminal trimethylammonium groups have values close to a typical single bond, and the second positive charge is localized there. In the crystal, the guanidinium ions are connected by C—H...O hydrogen bonds with the acetone molecules. C—H...π interactions are present between the guanidinium and acetone hydrogen atoms and the phenyl rings of the tetraphenylborate ions, leading to the formation of a two-dimensional supramolecular pattern along thebcplane.