5746-18-9Relevant articles and documents
Hydrogen bonds and conformational analysis of bis(1-methylisonicotinate) hydrochloride monohydrate by X-ray diffraction, vibrational spectra and B3LYP calculations
Szafran,Katrusiak,Dega-Szafran
, p. 46 - 53 (2006)
In the crystal structure of bis(1-methylisonicotinate) hydrochloride monohydrate, (MIN)2H·Cl·H2O, 1-methylisonicotinate betaines are hemiprotonated and form a homoconjugated cation through a short asymmetric O·H·O hydrogen bond of length 2.456(3) A?. Water molecules and Cl- anions are linked alternatively by hydrogen bonds of lengths 3.202(3) and 3.282(2) A? into planar zigzag chains along the [c] direction. The Cl- anion additionally interacts electrostatically with two positively charged nitrogen atoms of the neighboring MIN molecules. The most stable conformers of (MIN)2H·Cl·H2O, (MIN)2H·Cl, (MIN)2H·H2O and (MIN)2H have been analyzed by the B3LYP/6-31G(d,p) calculations in order to determine the influence of the anion and water molecule on the hydrogen bond in the homoconjugated MIN·H·MIN unit. The FTIR spectrum of (MIN)2H·Cl·H2O shows a broad and intense absorption in the 1500-400 cm-1 region, typical for short hydrogen bonds. The bands at 3416 and 3378 cm-1 confirm the presence of medium-strong hydrogen bonds between water molecules and Cl- anions.
X-ray and ab initio studies of the structure and vibrational spectra of 4-carboxy-1-methylpyridinium chloride
Szafran,Koput,Dega-Szafran,Katrusiak
, p. 66 - 81 (2006)
The effects of hydrogen bonding, inter- and intramolecular electrostatic interactions on the structure of 4-carboxy-1-methylpyridinium chloride (1-Me-isonicotinic acid chloride, 1-methyl-isonicotinium chloride), MINH·Cl, in the crystal and isolated molecule have been studied by X-ray diffraction, FTIR, Raman, 1H and 13C NMR spectra, B3LYP, MP2 and MP3 theoretical methods. In the crystal, the complex structure is stabilized by the O-H?Cl- hydrogen bond of 2.940(3) A?, and N+?Cl- interionic electrostatic interactions. In the isolated molecule, according to the B3LYP, MP2 and MP3 calculations, the Cl- anion is engaged in a shorter O-H?Cl- hydrogen bond of 2.931, 2.856 and 2.880 A?, respectively, and forms one distinct intramolecular electrostatic contact. The calculated bond lengths and bond angles are in good agreement with the X-ray data, except for the conformation of the COOH group, which is cis (syn) in the crystal and trans (anti) in the isolated molecule. The experimental solid-state vibrational spectra of MINH·Cl and MIND·Cl have been tentatively assigned on the basis of the MP2/ccpVDZ calculated frequencies and intensities. Analysis of the effects of quaternization of isonicotinic acid on the chemical shifts of the ring carbons and protons revealed correlations between the experimental carbon-13 and proton chemical shifts and the computed magnetic isotropic screening tensors.
