“…In many of the structures of CSD set showing that pattern, the C]O group is acceptor in H-bonding from hydrazido NH 2 donor, in a pattern of type (III), or eventually from other donor groups present in the molecule. In 4, the C]O group is involved as bifurcated acceptor in H-bonding with two anilino NH 2 donor groups giving rise to a tetrameric pattern across inversion centres, whose second level graph set descriptor is R 2 4 (8) (N-H/O: 0.90(2), 2.16(2), 3.019(2) A ˚, 158(2) , 1 À x, 1/2 + y, 1/2 À z; N-H/O: 0.88(2), 2.17(2), 3.049(2) A ˚, 173(2) , x, 1/2 À y, À1/2 + z). Concerning the hydrazido NH 2 atoms they act as donors in weaker H-bonding with anilino NH 2 and p-aromatic acceptors.…”