Darstellung und Kristallstruktur von Calciumimid,CaNH

Synthesis and Crystal Structure of Calcium Imide, CaNH Single-crystals of calcium imide were obtained for the first time by the reaction of a mixture of calcium amide with sodium amide at 850°C in an autoclave for salt melts. After cooling the autoclave to room temperature the crystals are embedded in solid Na which was extracted by liquid ammonia. The structure of calcium imide was determined from single-crystal diffractometer data: space group Fm3 m, Z = 4, a = 5.143(1) Å, R/R_w = 0.032/0.028 mit N(F ${}_{\text{º}}^{\text{2}}$ ? 3σ(F ${}_{\text{º}}^{\text{2}}$ )) = 26, N(Var.) = 5. Ca and N atoms are arranged in the motif of the NaCl structure type. The hydrogen atoms of the imide groups are disordered within the Ca octahedra, and they occupy a six fold split position.     

Alfréd Rényi

Probability Theory and Related Fields -     

Group VA effects on surfactant aggregation number and dye solubilization efficiency

The effects of changing the charge-bearing atom in the polar head of a surfactant ion on micelle size and dye solubilization efficiency were investigated. Replacement of nitrogen in decyltrimethylammonium bromide by phosphorus or arsenic increases the micellar aggregation number by at least 20% in 0.5 m NaBr solutions. The ability of the surfactants to solubilize the dye Orange-OT is only slightly affected by the substitution of phosphorus for nitrogen, but it is lowered appreciably by the substitution of arsenic.     

Defect interactions in intrinsic silver chloride

Approximate formulae are developed for the activity coefficients of vacancies and interstitials in intrinsic silver chloride. The numerical values are compared with the Debye-Hückel approximation and the useful range of the formulae is discussed.     

Efficient dynamic kinetic resolution of secondary amines with Pd on alkaline earth salts and a lipase

Combination of Pd, supported on alkaline earth type supports with a lipase results in a selective catalytic system for dynamic kinetic resolution of benzylic amines.     

Investigation of the low-lying levels of 179Hf with the (n, γ) and (n,e) reactions

The excited levels of ¹⁷⁹Hf are investigated using the thermal neutron capture γ-ray and conversion electron spectra measured with the bent crystal diffraction spectrometer in Risø and the β-spectrograph in Riga. The level scheme contains the odd parity rotational bands $\text{7}\text{2}{}^{\mathrm{?}}\text{[514],}\text{1}\text{2}{}^{\mathrm{?}}\text{[510],}\text{5}\text{2}{}^{\mathrm{?}}\text{[512],}\text{1}\text{2}{}^{\mathrm{?}}\text{[521],}\text{3}\text{2}{}^{\mathrm{?}}\text{[512]}$ and $\text{7}\text{2}{}^{\mathrm{?}}\text{[503]}$. The energies of these levels and the intensity ratios of the transitions between them are calculated taking into account the rotation-particle coupling (RPC). The following even parity levels are proposed: 859.0 and 942.2 keV $\text{(}\text{7}\text{2}{}^{\mathrm{+}}\text{and}\text{9}\text{2}{}^{\mathrm{+}}\text{of the}\text{7}\text{2}{}^{\mathrm{+}}\text{[633]}\text{band}\text{)}$; 1004.1 and 1079.2 keV $\text{(}\text{5}\text{2}{}^{\mathrm{+}}\text{and}\text{7}\text{2}{}^{\mathrm{+}}\text{of the}\text{9}\text{2}{}^{\mathrm{+}}\text{[624] + Q(22)}\text{band}\text{)}$; 1186.0, 1199.2 and 1296.4 keV $\text{(}\text{1}\text{2}{}^{\mathrm{+}}\text{,}\text{5}\text{2}{}^{\mathrm{+}}\text{and}\text{3}\text{2}{}^{\mathrm{+}}\text{of the}\text{1}\text{2}{}^{\mathrm{+}}\text{[651]}\text{band}\text{)}$. The levels at 1249.8, 1269.7, 1432.9, 1482.2 and 1755.5 keV, supported by the analysis of the γγ coincidence spectrum and Ge(Li) singles data, are discussed.