Figure 6 A perspective view of the two-dimensional hydrogen-bonded network structure of (II), showing the centrosymmetric head-to-tail cyclic R22(14) hydrogen-bonded piperidinium–amide associations in the INIPA cationic dimer and the structure extensions. Hydrogen bonds are shown as dashed lines and non-associative H atoms have been omitted. (For symmetry codes, see Table 2.)