Phosphoalkenes (1), (R, RI, and RII = H, Hal, Nalk2) show alternative nucleophilic properties towards HX acids or transition metal salts, and depending upon reagent characteristics form addition products throught one of P=C double bond atoms. Coordination of a ligand to a cation by its π-electron donor is also observed due to quazidegeneration of higher occupied molecular orbital. 相似文献
Abstract The infrared (IR) and Raman spectra of MgHPO4. 3H2O and of a series of partially deuterated analogues as well as the IR spectra of MnHPO4. 3H2O have been recorded and interpreted. The analysis of the IR spectra in the HOD bending region rules out the possibility of existence of H3OC+ ions in the structure. 相似文献
Abstract The influence of classical systems connected with phosphorus atom: >P(Y)-C(R)=C<, >P(Y)-C[tbnd]S- and unusual ones, -P=E and P[tbnd]S- on spatial and electronic structure of or-ganophosphorus compounds has been considered. On the complex analysis ground of polarity and polarizability data, obtained for model olefines, imines, acetylenes and nitriles the existence of nonformal similarity between this compounds classes has been demonstrated. It is reflected in analogy of conformational behaviour and electron effects, realized with participation of multiple carbon, nitrogen and phosphorus bonds: 相似文献
Abstract The series of copper (I) complexes with thiophosphite ligands was prepared and examined to determine the factors that affect the coordination mode of the ligand with metal. 相似文献
Solution-state nitroso monomer-azodioxide equilibria and conformational freedom of several aromatic dinitroso derivatives, differing in the spacer group between the aromatic rings, were studied by one- and two-dimensional variable temperature 1H NMR spectroscopy and by quantum chemical calculations. The proton signals of nitroso monomer-azodioxide mixtures revealed by low-temperature NMR were assigned and validated using B3LYP-D3/6-311+G(2d,p)/SMD level of theory. In almost all cases, a preference towards the formation of only one azodioxy isomer of aromatic dinitroso compounds was found, which was assigned to Z-dimer according to computational data. Nevertheless, the computed small energy difference between the Z- and E-isomer could not account for the extreme preference for Z-dimer formation, indicating an influence of entropic or solvent effects. The formation of shorter oligomers in solution was excluded based on integrated 1H NMR signal intensities. The experimental results indicated an average dimerization Gibbs energy of about ??5 kJ/mol at 223 K and were found to be in very good correlation with dimerization energies obtained by solution-phase optimization.
A bottle screening method to detect smuggling drugs was developed based on a series of rapid and automated magnetic resonance measurements. Liquid alteration is detected by evaluating chemical and physical properties of the liquid, scanning the bottle with a compact, non-contact magnetic resonance probe. Chemical and molecular diffusion changes are detected by means of the magnetic resonance relaxation time. The inspection device automatically detects the presence of concealed powders dissolved in liquids in a second timescale. The non-ionizing, non-contact method effectively screens bottles, regardless of their shape, size, and color. The proposed system configuration does not require a large magnet generating uniform magnetic fields; rather it inspects the liquid using a compact probe positioned on the wall of the bottle. For a variety of samples tested, the screening does not require detailed information on the expected content of the bottle. 相似文献
The transport of a reactive solute by diffusion and convection in a thin (or long) curved pipe is considered. Using asymptotic analysis with respect to the pipe’s thickness, the effective model for solute concentration is formally derived. A simple approximation is computed, showing explicitly the effects of the pipe’s geometry in nature and magnitude. 相似文献