Stereoisomerism of N-(1-Propenyl)thiobenzamide

A prototropic rearrangement of N-prop-2-enylbenzocarbothioamide afforded two stereoisomeric N-prop-1-enylbenzocarbothioamides (IIa, b) isolated as individual compounds. The stereoisomerism is due to hindered rotation around thioamide bond C(S)-N and also to -diastereoisomerism. The configuration of the isolated isomers was investigated by IR spectroscopy, AM1 and PM3 methods. In the molecules occurs the p,-conjugation with participation of nitrogen atom and multiple bonds resulting in formation of a united delocalized MO in the planar fragment C(S)-NC = C.     

Spectroscopic study of germanium-containing compounds

Conclusions The values of C=0 in the IR spectra and the position of the band from the n ^* electronic transition in the UV spectra of the amides R¹CONR²R³ vary linearly with the inductive effect of the R¹ substituent (for R²=R³=H, Alk). This may indicate the absence of the intramolecular coordination Ge 0, where or. The substituent R¹=Ge(C₂H₅)₂ exhibits electron-acceptor properties besides a +I-effect.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 2, pp. 349–352, February, 1984.     

Molecular and Electronic Structure of Trimethylsilylpropiolamides

The specific features of molecular and electronic structure of trimethylsilylpropiolic acid amides were studied by means of IR spectroscopy and quantum chemistry (AM1). The competition between p,-conjugation in the amide fragment and ,-conjugation in the ethynylcarbonyl group CC-C=O was established. The prevailing conformers were revealed, their geometrical parameters were established, the barriers to internal rotation around the amide C-N bond were calculated for acyclic (13 kcal mol^-1) and heterocyclic (8.12 kcal mol^-1) amides.     

Synthesis and crystal structure of ternary molybdate compound K<Subscript>5</Subscript>Pb<Subscript>0.5</Subscript>Hf<Subscript>1.5</Subscript>(MoO<Subscript>4</Subscript>)<Subscript>6</Subscript>

Single crystals of triple molybdate of composition 5:1:3 K₅Pb_0.5Hf_1.5(MoO₄)₆ have been grown and their crystal structure has been solved from X-ray diffraction data (an automated diffractometer X8 APEX, MoK _α -radiation, 2173 F(hkl), R = 0.0321). Trigonal unit cell parameters are: a = b = 10.739(2) Å, c = 37.933(9) Å; V = 3789(1) ų, Z = 6, ρ_calc = 4.014 g/cm³, space group \(R\bar 3\). Three-dimensional mixed framework of the structure is formed by two types of MoO₄ tetrahedra and Pb and Hf octahedra linking via common O-vertices. Potassium atoms of three types occupy large vacancies in the framework.     

Human immunoglobulin adsorption investigated by means of quartz crystal microbalance dissipation, atomic force microscopy, surface acoustic wave, and surface plasmon resonance techniques

Time-resolved adsorption behavior of a human immunoglobin G (hIgG) protein on a hydrophobized gold surface is investigated using multitechniques: quartz crystal microbalance/dissipation (QCM-D) technique; combined surface plasmon resonance (SPR) and Love mode surface acoustic wave (SAW) technique; combined QCM-D and atomic force microscopy (AFM) technique. The adsorbed hIgG forms interfacial structures varying in organization from a submonolayer to a multilayer. An "end-on" IgG orientation in the monolayer film, associated with the surface coverage results, does not corroborate with the effective protein thickness determined from SPR/SAW measurements. This inconsistence is interpreted by a deformation effect induced by conformation change. This conformation change is confirmed by QCM-D measurement. Combined SPR/SAW measurements suggest that the adsorbed protein barely contains water after extended contact with the hydrophobic surface. This limited interfacial hydration also contributed to a continuous conformation change in the adsorbed protein layer. The viscoelastic variation associated with interfacial conformation changes induces about 1.5 times overestimation of the mass uptake in the QCM-D measurements. The merit of combined multitechnique measurements is demonstrated.     

Target synthesis of bioactive thioglycolurils,based on QSAR predictions

Target synthesis of substituted thioglycolurils possessing sedative activity predicted by preliminary 3D-QSAR simulation of bioactive structures has been carried out.