N-[3-(Di­methyl­amino)­prop­yl]-N,N′,N′,N′′,N′′-penta­methyl­guanidinium tetra­phenyl­borate

In the title salt, C₁₁H₂₇N₄⁺·C₂₄H₂₀B⁻, the C—N bond lengths in the central CN₃ unit of the guanidinium ion are 1.333 (4), 1.334 (4) and 1.351 (4) Å, indicating partial double-bond character. The C atom of this unit is bonded to the three N atoms in a nearly ideal trigonal-planar geometry [N—C—N angles = 118.8 (3), 120.0 (3) and 121.2 (3)°] 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 have values in the range 1.459 (4)–1.478 (4) Å, close to a typical single bond. In the crystal, there are C—H...π inter­actions between the guanidinium H atoms and the phenyl rings of the tetra­phenyl­borate ion. These inter­actions combine to form a ladder of linked chains of ions which runs parallel to the c axis.

2-[4-(Carbazol-9-yl)phen­yl]-1,3-diethyl-1,3-di­phenyl­guanidine

In the title compound, C₃₅H₃₂N₄, the C—N bond lengths in the guanidine part are 1.286 (3), 1.387 (2) and 1.414 (2) Å, indicating double- and single-bond character. The N—C—N angles are 114.48 (17), 118.78 (17) and 126.72 (17)°, showing a deviation of the CN₃ plane from an ideal trigonal–planar geometry. The carbazole ring system is almost planar (r.m.s. deviation = 0.002 Å). In the crystal, mol­ecules are connected by weak C—H...N hydrogen bonds, generating a zigzag chain along the ac plane. Weak π–π inter­actions [centroid–centroid distance = 3.785 (1) Å] between two phenyl rings of the guanidine moiety are also present.