Kerr effect of CN- molecules in KCl crystals

The electric field alignment of substitutional CN^- molecules in KCl crystals was studied by measurements of the field-induced optical birefringence (Kerr-effect). The electric field, temperature, wavelength and concentration dependence of the Kerr-effect and its pronounced anisotropy is found in quantitative agreement with a paraelectric alignment model for 〈111〉 oriented CN^- molecules, which have electronic absorption transitions hidden under the fundamental crystal absorption, and are characterized by an anisotropic polarizability of $\text{α}{}_6\text{? α}{}_{\mathrm{\perp }}\text{= 1.60}\text{A}\text{?}{}^3$.     

Bildung siliciumorganischer Verbindungen. 87. Das 2,8,9-Trioxa-1,3,5,7-tetrasilaadamantan

Formation of Organosilicon Compounds. 87. 2,8,9-Trioxa-1,3,5,7-Tetrasilaadamantane Hydrolysis of cis-cis-1,3,5-tribromo-1,3,5-tri-t-butyl-1,3,5-trisilacyclohexane yields the trisilanole 2 (mp. 205°C) which forms the tetrasilaadamantane 3 with SiCl₄/et₂NH. Hydrolysis of 3 yields 4 (Formulae see “Inhaltsübersicht”).     

Atomic structure of Cu{0 0 1}c(2 × 2)-Cl

A LEED intensity analysis of Cu{0 0 1}c(2 × 2)-Cl has given an excellent fit of theory to experiment with Cl in the fourfold symmetrical hollows in a simple overlayer structure with a Cu-Cl bond length of 2.38 Å. This structure is consistent with an analysis of angle-resolved photoemission measurements made in the same experiments and published elsewhere. These results help confirm the LEED analysis of the analogous system Ag{0 0 1}c(2 × 2)-Cl which gave the same structure, but had been rejected by an independent photoemission analysis.     

Makrocyclische Ionophore beruhend auf oligomeren Terephthaldiamiden mit von Gastmolekülen abhängiger Selektivität

Macrocyclic Oligolactams Based on Terephthalic Acid as Ionophores with Selectivity Depending on Included Guest Molecules Macrocyclic 20- to 60-membered oligolactam hosts exhibit ion selectivities in poly(vinyl chloride) membranes which depend on the ring size and on the substituents of the amide N-atoms. The selectivity may be changed by loading the macrocyclic host with CHCl₃ as guest molecule.