N,N,N ',N ',N"-Pentamethyl-N"-[3-(tri-methylazaniumyl)propyl]guanidinium bis(tetraphenylborate)

In the crystal structure of the title salt, C12H30N42+center dot 2C(24)H(20)B(-), the C-N bond lengths in the central CN3 unit of the guanidinium ion are 1.3388 (17), 1.3390 (16) and 1.3540 (17) angstrom, indicating partial double-bond character in each. 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 C-methyl groups of the guanidinium moiety, all have values close to a typical single bond [1.4630 (16)-1.4697 (17) angstrom]. C-H center dot center dot center dot pi interactions are present between the guanidinium H atoms and the phenyl C atoms of one tetraphenylborate ion. The phenyl rings form a kind of aromatic pocket, in which the guanidinium ion is embedded.