Crystal and molecular structure, hydrogen bonding and electrostatic interactions of bis(homarine) hydrogen perchlorate studied by X-ray diffraction, DFT calculations, FTIR and Raman spectroscopies

✍ Scribed by M. Szafran; A. Katrusiak; Z. Dega-Szafran

• Publisher: Elsevier Science
• Year: 2007
• Tongue: English
• Weight: 577 KB
• Volume: 839
• Category: Article
• ISSN: 0022-2860
• DOI: 10.1016/j.molstruc.2006.10.049

✦ Synopsis

The crystals of bis(homarine)hydrogen perchlorate, (HOM) 2 HAEClO 4 , (1) are orthorhombic, space group C2/c, with a pair of HOM molecules bridged by a symmetrical OAEHAEO hydrogen bond of 2.480(3) A ˚. In the homoconjugated cation, (HOMAEHAEHOM) + , the H-bonded proton is in centre of inversion. The COO groups are inclined by 29.98(18)°to the plane of the pyridine rings, but pyridine rings are coplanar. The ClO 4

À anion additionally interacts electrostatically with the positively charged nitrogen atoms of the neighbouring HOM molecules. The most stable conformer of (HOM) 2 HAEClO 4 (2) and four homoconjugated cations, (HOM) 2 H, (3-6) were analysed by the B3LYP/6-31G(d,p) calculations in order to determine the influence of the anion on the hydrogen bonds in the HOMAEHAEHOM unit. The FTIR spectrum of the (HOM) 2 HAEClO 4 shows a broad and intense absorption in the 1500-400 cm À1 region, typical of short hydrogen bonds.