COMPLEXES OF THE PROTON SPONGE 1,8-BIS(DIMETHYLAMINO)NAPHTHALENE (DMAN) .3. STRUCTURE OF [DMANH]+[PENTACHLOROPHENOLATE]-.[PENTACHLOROPHENOL]2 AT 100-K

(8-Dimethylamino-1-napthyl)dimethylammonium pentachlorophenolate-pentachlorophenol (1/2), C14H19N2+.C6Cl5O-.2C6HCl5O, M(r) = 1013.3, orthorhombic, P2(1)2(1)2(1), a = 11.363 (2), b = 16.676 (2), c = 20.307 (2) angstrom, V = 3847.9 (4) angstrom 3, Z = 4, D(x) = 1.749 g cm-3, lambda(Mo K-alpha) = 0.71073 angstrom, mu = 11.2 cm-1, F(000) = 2024, T = 100 K, final R = 0.0271 and wR = 0.0231 for 7630 reflections with I greater-than-or-equal-to 2.5-sigma(I). The 'proton sponge' 1,8-bis(dimethylamino)naphthalene (DMAN) accepts a proton from one of the three pentachlorophenols (PCPs) resulting in the formation of a strong asymmetric intramolecular [N-H...N]+ hydrogen bond with N...N and N-H distances and N-H...N angle of 2.555 (3), 1.11 (2) angstrom and 162 (2)-degrees respectively. The [PCP]-anion and the two neutral PCP residues form an isolated hydrogen-bonded cluster. The OH donors of these hydrogen bonds are each involved in an asymmetric three-center hydrogen bond with a strong O-H...O- intermolecular branch and a weak O-H...Cl intramolecular branch.