Bis(L-proline) hydrogen(1+) perchlorate

In the title compound, 2C(5)H(9)NO(2).H+. ClO4-, two proline residues are linked by a strong O-H . . .O hydrogen bond with an O . . .O distance of 2.474 (6) Angstrom. Conformational disorder is observed in the pyrrolidine rings of the two proline residues. In one of the residues, both the major and minor conformers adopt conformations intermediate between half-chair and envelope, whereas in the other residue, they adopt envelope conformations. The crystal structure is stabilized by a number of N-H . . .O hydrogen bonds.