Proton magnetic resonance spectra of certain heteroorganic compounds of silicon and germanium

Conclusions A comparison of the PMR spectra of a number of saturated and unsaturated organic compounds of silicon and germanium shows that in the case of unsaturated compounds, an appreciable role is played by effects of d–p conjugation, which are stronger for silicon compounds.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 7, pp. 1312–1313, July, 1964     

Unexpected conversions of selected heteroorganic compounds

A few unexpected conversions of selected heteroorganic compounds are described, including the formation of N‐sulfonyl sulfenamide derivatives and the mixed phosphinyl‐sulfenyl anhydrides in the reactions of sulfinyl chlorides with α‐phenylethylamine or t‐butyl‐phenylphosphine oxide, respectively. Unexpected reactions of the ortho hydroxyalkyl‐substituted diaryl sulfoxides and hypervalent sulfur and selenium derivatives, induced by triphenylphosphine, are also presented. Attempts to rationalize the observed reaction courses are briefly discussed. © 2002 Wiley Periodicals, Inc. Heteroatom Chem 13:437–442, 2002; Published online in Wiley Interscience (www.interscience.wiley.com). DOI 10.1002/hc.10077     

Preparation and X-ray diffraction studies of curium hydrides

Curium hydrides were prepared by reaction of curium-248 metal with hydrogen and characterized by X-ray powder diffraction. Several of the syntheses resulted in a hexagonal compound with average lattice parameters of a₀ = 0.3769(8) nm and c₀ = 0.6732(12) nm. These products are considered to be CmH_3?δ by analogy with the behavior of lanthanide-hydrogen and lighter actinide-hydrogen systems. Face-centered cubic products with an average lattice parameter of a₀ = 0.5322(4) nm were obtained from other curium hydride preparations. This parameter is slightly smaller than that reported previously for cubic curium dihydride, CmH_2+x (B. M. Bansal and D. Damien, Inorg. Nucl. Chem. Lett., 6, 603, 1970). The present results established a continuation of typical heavy trivalent lanthanide-like behavior of the transuranium actinide-hydrogen systems through curium.     

X-ray diffraction studies of mesomorphic ferrocene diesters

Abstract

The crystal and molecular structure of 1,l ′-bis(4′-pentyloxybiphenyl)ferrocene dicarboxylate ester (1) has been determined by X-ray diffraction at 295 and 160K. The molecule is found to exist at both temperatures in an extended S geometry. The carboxyl groups are essentially coplanar with the cyclopentadienyl rings but almost perpendicular to the attached phenyl ring. Low angle X-ray diffraction of three diesters in the smectic phases were also studied. The results were not very definitive because of the lack of thermal stability for the monotropic phase behaviour. Nevertheless, the layer spacing of about 47 A for one of the compounds at 409K is consistent with the extended S shape conformation.     

X-ray diffraction studies and interstitial model for liquid water

Samoilov's interstitial model for liquid water is considered. It is shown that geometrically different frameworks and different positions of cavity molecules lead to comparable degrees of agreement with the experimental radial distribution function. The meaning and the limits of these agreements are discussed.     

Synthesis of dihydrobenzoxazine pyrrolidone spirocyclic compounds

A simple and efficient synthetic strategy for the preparation of dihydrobenzoxazine spirocyclic compounds was reported via the cycloaddition reaction of o-succinimide-substituted benzaldehyde with nitrobenzene. The reactions can be conducted under very mild reaction conditions (room temperature) using 10?mol% of Cs₂CO₃ as catalyst. A series of dihydrobenzoxazine pyrrolidone spirocyclic compounds were afforded in moderate to good yields. This strategy provides a new direction for the synthesis and study on biological activities of dihydrobenzoxazine pyrrolidone spirocyclic compounds.