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

不斉を有する複素環式化合物のクリスタルエンジニアリング

取得学位：博士(工学)，学位授与番号：博甲第702号，学位授与年月日：平成17年3月22日,学位授与年：200

Crystal structures of racemic and enantiomeric 5-isopropyl-5-methylhydantoin

Crystal structures of racemic and enantiomeric 5-isopropyl-5-methylhydantoin (IPrMH) have been determined by single crystal X-ray diffraction. Melting temperatures and solid state infrared spectra are also measured. Racemic IPrMH has a lower melting temperature than the pure enantiomer by 25 °C. The infrared spectrum of racemic IPrMH is identical with that of the pure enantiomer. Nevertheless, the racemic IPrMH doesn’t crystallize as a conglomerate but as a racemic compound. The racemic and the enantiomeric crystals are very similar to each other in molecular geometries and intermolecular interactions. In the both cases, the molecules are connected via N−H···O hydrogen bonds to form R22(8) rings, and these rings are linked into infinite one-dimensional tapes. In the racemic crystal, a single tape is composed of single enantiomer and itself is homochiral

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

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 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

Crystal Structure of 4-Dimethylaminoazobenzene-4′-sulfonyl-L-tryptophan Dimethylsulfoxide Solvate

Crystals of 4-dimethylaminoazobenzene-4′-sulfonyl-L-tryptophan dimethylsulfoxide solvate (Dabs-Trp·DMSO) are monoclinic, space group P21 with a = 12.941(6)Å, b = 7.760(3)Å, c = 14.131(7)Å, β = 103.161(8)° and Z = 2. The structure was solved by direct methods (SIR88) and refined to a final R value of 0.058 for 3152 reflections (I > 2.00σ(I)). The molecular geometries and conformations are comparable to the typical values of azobenzene and L-tryptophan. The DMSO molecule is involved in the intermolecular hydrogen bonds with the sulfonamide NH and the carboxyl OH groups of different Dabs-Trp molecules. The hydrogen-bonded chains propagate along the b axis, and are constructed from molecules related by a two-fold screw axis. The sulfonamide S=O and the carboxyl C=O groups do not participate in hydrogen bonding