Crystal structure of N''-benzyl-N''-[3-(benzyl-dimethyl-aza-nium-yl)prop-yl]-N,N,N',N'-tetra-methyl-guanidinium bis-(tetra-phenyl-borate).

In the crystal structure of the title salt, C24H38N4 (2+)·2C24H20B(-), the C-N bond lengths in the central CN3 unit of the guanidinium ion are 1.3364 (13), 1.3407 (13) and 1.3539 (13) Å, indicating partial double-bond character. The central C atom is bonded to the three N atoms in a nearly ideal trigonal-planar geometry and the positive charge is delocalized in the CN3 plane. The bonds between the N atoms and the terminal methyl groups of the guanidinium moiety and the four C-N bonds to the central N atom of the (benzyl-dimethyl-aza-nium-yl)propyl group have single-bond character. In the crystal, C-H⋯π inter-actions between the guanidin-ium H atoms and the phenyl C atoms of the tetra-phenyl-borate ions are present, leading to the formation of a two-dimensional supra-molecular pattern parallel to the ac plane.