Mixed-metal ethylenediaminetetraacetates of neodymium and alkaline earths

Conclusions In solution, the complexes M^II(NdA)₂ do not have a polynuclear structure. In the conditions studied, hydroxo polynuclear complexes including EDTA and M^II and Nd³⁺ ions are also not formed. Our results are not inconsistent with the hypothesis that the solid complex Ca(NdA)₂·17H₂O has a polynuclear structure and that the polynuclear character is successively weakened as Ca²⁺ is replaced by Sr²⁺ and Ba²⁺.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 6, pp. 1235–1239, June, 1977.     

Reactions de photoaddition de benzo[b]selenophenes avec l'acetylene dicarboxylate de methyle et avec le dichloro-1,2 ethylene

Photoirradiated in presence of acetophenone, benzo[b]selenophene and its 3-methyl derivative add to dimethyl acetylenedicarboxylate. In each ease, the primary reaction product is unstable and has not been isolated. Photoexeited in its triplet state (the energy of which is in the neighbourhood of 69 $\text{kcal}\text{mole}$) benzo[b]selenophene and its 2- and 3-methyl, 2,3 dimethyl, 3 acetoxy and 2-methyl-3-acetoxy derivatives add to 1,2 dichloroethylene leading to cyclobutanes. Neither cyclo-addition occurs in absence of photosensitiser. Single-crystal X-ray analysis gave the structures of the two adducts of 3-acetoxybenzo[b]selenophene with trans-1,2-dichloroethylene. In both compounds the chlorine atoms are trans.     

Anodic oxidation of olefins in presence of fluorine anion

Russian Chemical Bulletin -     

A single crystal study of eight-layer barium managanese oxide,BaMnO3

A single crystal study of hydrothermally prepared eight-layer BaMnO₃ has been carried out which confirms the (Zhdanov notation) 121121 layer stacking scheme for the BaO₃ layers. The MnO₆ octahedra share faces in strings of four, and these strings are connected to each other by corner sharing. The compound has an hexagonal unit cell of dimensions a = 5.667 ± 0.003 and c = 18.738 ± 0.009 Å, probable space group $\text{P6}{}_3\text{mmc}\text{, Z = 8}$. Its structure has been determined from 352 independent reflections, of which 242 were considered observed, collected manually by a counter technique and refined to a conventional R value of 0.079.     

Electrical Resistivity and Magnetic Susceptibility Measurements on Copper Arsenides

Electrical resistivity (4.2–800°K) and magnetic susceptibility (4.2–500°K) measurements are carried out on Cu_3–xAs, Cu_5–xAs₂ and the recently obtained, tetragonal Cu₂As. All three compounds appear to be metallic conductors, but have high residual resistances because of the large defect concentrations (resulting from non-stoichiometry and preparation method). Cu_3–xAs is diamagnetic; Cu_5–xAs₂ is Pauli-paramagnetic; Cu₂As has a very small, constant, positive susceptibility above room temperature and a more pronounced Curie-Weiss behaviour at lower temperatures. The Pauli-paramagnetic contributions have been estimated. A slight anomaly in the electric and magnetic behaviour of Cu_3–xAs is observed at 220°K. To clarify the high-temperature phenomena, a series of D.T.A. and X-ray experiments has also been carried out.