Vibrational spectra and normal coordinate analysis of lithium pyruvate monohydrate and its isotopic compounds

IR and Raman spectra of lithium pyruvate monohydrate and its O- and C-deuterated and 13C- and 18O-substituted compounds have been recorded in the solid state, and the observed bands have been assigned by using the isotope effects and the normal coordinate calculations based on the gem-diol structure (lithium 2,2-dihydroxypropionate). The refined force constants have well reproduced the observed frequencies and the 13C- and 18O-shifts. These results support the structures of these compounds discussed by many authors. The potential energy distributions show that many vibrational modes are very complicated except for the well-known group vibrations. The additive property of the isotopic frequency shifts has also been discussed

Synthesis and crystal structure of (S)-5-isopropyl-5-methyl-2-thiohydantoin

(S)-5-Isopropyl-5-methyl-2-thiohydantoin was synthesized by one-pot reaction of α-methyl-L-valine and thiourea in the absence of solvent. The crystal structure of this compound has been determined from single crystal X-ray diffraction data. This is the first report on the crystal structure of a homochiral 5-substituted 2-thiohydantoin with the unsubstituted NH groups. This compound, C7H12N2OS crystallizes in the chiral orthorhombic space group P212121 with four molecules in the unit cell. The unit cell parameters are: a = 8.2798(12) Å, b = 8.6024(13) Å, c = 12.826(2) Å and V = 913.6(2) Å3. In the crystals, the thioamide and amide N-H of one molecule are hydrogen-bonded to the thioamide C=S group of neighboring molecules to form rings with the R22(8) graph-set motif, and these rings are linked into infinite one-dimensional tapes

Crystal structure of phenolphthalein

金沢大学大学院自然科学研究科先端機能物質金沢大学工学

Crystal structures and conformations of 5-benzyl-2-thiohydantoin and its 1-acetylated derivative

金沢大学理工研究域物質化学系The crystal structures of 5-benzyl-2-thiohydantoin (5-BTH) and 1-acetyl-5-benzyl-2-thiohydantoin (1-Ac-5-BTH) have been determined by X-ray diffraction. In the 5-BTH crystals, the enantiomeric (R)- and (S)-5-BTH molecules are connected to form cyclic dimers via the hydrogen bonds of the thioamide and the amide moieties. On the other hand, the intermolecular hydrogen bonds in 1-Ac-5-BTH crystals form an infinite chain. These differences in the hydrogen bond pattern are also discussed in the IR and Raman spectra. The ab initio molecular orbital calculations (Gaussian 03) with 6-31G(d,p) basis set were carried out for 5-BTH and 1-Ac-5-BTH to get the preferred conformation. Copyright © Taylor & Francis Group, LLC.全文公開20100

Crystal structure of o-(p-N,N-dimethylaminobenzoyl)benzoic acid

金沢大学大学院自然科学研究科先端機能物質金沢大学工学