Crystal structure of N-[3-(di­methyl­amino)­prop­yl]-N′,N′,N′′,N′′-tetra­methyl-N-(N,N,N′,N′-tetra­methyl­form­amid­in­ium­yl)guanidinium bis­(tetra­phenyl­borate)

In the title salt, C15H36N6 (2+)·2C24H20B(-), the three N-C bond lengths in the central C3N unit of the bis-amidinium ion range between 1.388 (3) and 1.506 (3) Å, indicating single- and double-bond character. Furthermore, four C-N bonds have double-bond character. Here, the bond lengths range from 1.319 (3) to 1.333 (3) Å. Delocalization of the positive charges occurs in the N/C/N and C/N/C planes. The dihedral angle between both N/C/N planes is 70.5 (2)°. In the crystal, C-H⋯π inter-actions between H atoms of the cation and the benzene rings of both tetra-phenyl-borate ions are present. The benzene rings form aromatic pockets, in which the bis-amidinium ion is embedded. This leads to the formation of a two-dimensional supra-molecular pattern along the ab plane.