Crystal chemistry of protonated 1,2-bis(di-R-aminomethyl) benzenes. Part VI: 1,2-bis(diethylaminomethyl)-4,5-dichlorobenzene perchlorate

The crystals of a 1:1 complex of 1,2-bis(diethylaminomethyl)-4,5-dichlorobenzene perchlorate with HClO4 were studied using X-ray diffraction and FT-IR spectroscopy. There are two symmetry-independent ionic pairs in the crystal, monoclinic, space group P2(1)/n. In both symmetry-independent cations, the diethylaminomethyl substituents are in a similar Z conformation relative to the phenyl moieties, however. significant conformational differences in the diethylaminomethyls have been noted. The diethylaminomethyls are linked by intracationic N+-(HN)-N-... hydrogen bonds of 2.758(9) and 2.721(7) Angstrom in two symmetry-independent cations. The protons in these H-bonds are disordered in two off-center sites, which is most likely to be connected with the considerable disorder of the perchlorate anions. The IR spectrum of the crystals shows a broad intense band and a relatively intense continuous absorption indicating relatively large proton polarizability in the intramolecular hydrogen bond of a medium length. (C) 2002 Elsevier Science B.V. All rights reserved.