Synthesis of compounds with polymetallic chains including boron atoms of a carborane cage

Compounds with B-Hg-Ge or Ge-Hg-B-B-Hg-Ge chains in which the boron atoms are members of a carborane cage have been prepared by treatment of the digermane (C₆F₅)₃GeGeEt₃, with B-mercurated derivatives of the carboranes m-C₂H₂B₁₀H₉HgX (X = Cl, OCOCF₃) and m-C₂H₂B₁₀H₈(HgOCOCF₃)₂. Treatment of HGe(C₆F₅)₂Ge(C₆F₅)₂H with methyl(m-carboran-9-yl)mercury resulted in a compound with a B-Hg-Ge-Ge-Hg-B chain containing two carborane cages at the ends of the chain. The compound prepared can take part in oxidative insertion of Pt(PPh₃)_n (n = 3,4) to give the chains B-Hg-Pt-Ge, Ge-Pt-Hg-B-B-Hg-Ge and B-Hg-Pt-Ge-Ge-Pt-Hg-B.     

The mercuration of ortho- and meta-carboranes

The mercuration of ortho- and meta-carboranes is described. This mercuration proceeds at the boron atom of the icosahedral at position 9.     

Synthesis and Structure of B-Carboranylphosphonates

Abstract

Photolysis of bis(m-carboran-9-yl)mercury and bis(p-carboran-2-yl)mercury in trimethylphosphite leads to the formation of dimethyl ethers of (m-carboran-9-yl)- and (p-carboran-2-yl)-phosphonic acids:     

Effect of light assisted collisions on matter wave coherence in superradiant Bose-Einstein condensates

We investigate experimentally the effects of light assisted collisions on the coherence between momentum states in Bose-Einstein condensates. The onset of superradiant Rayleigh scattering serves as a sensitive monitor for matter-wave coherence. A subtle interplay of binary and collective effects leads to a profound asymmetry between the two sides of the atomic resonance and provides far bigger coherence loss rates for a condensate bathed in blue detuned light than previously estimated. We present a simplified quantitative model containing the essential physics to explain our experimental data and point at a new experimental route to study strongly coupled light matter systems.     

Studies on automated flameless atomic absorption spectrometry

Summary A new device for automated sample injection in flameless AAS with graphite tubes had been investigated. Using solutions of Cd, Pb, Cu, and Ni the attainable precision, the carry-over factor by additional experiments with ⁸⁹Sr, the lifetime of commercially available graphite tubes as well as the influence of some selected matrix types and a pyrolytic coating on the surface of the graphite tubes upon measured values had been studied. The results of these studies together with the hereby resulting advantages of the system and possible future applications are discussed.

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Untersuchungen zur automatisierten flammenlosen Atomabsorptionsspektrometrie

Zusammenfassung Ein neuartiges Gerät zur automatischen Probendosierung bei der flammenlosen AAS mit Graphitrohren wurde untersucht. Mit Lösungen von Cd, Pb, Cu und Ni wurde die erreichbare Reproduzierbarkeit, der Verschleppungsfaktor durch zusätzliche Experimente mit ⁸⁹Sr, die Lebensdauer kommerziell erhältlicher Graphitrohre, der Einfluß einiger ausgewählter Matrices sowie einer pyrolytischen Beschichtung der Oberfläche der Graphitrohre auf die Meßwerte ermittelt. Die Ergebnisse der Studien, die hieraus ersichtlichen Vorteile des Systems sowie zukünftige Einsatzmöglichkeiten werden diskutiert.

Presented at the 6th Annual Symposium on Recent Advances in the Analytical Chemistry of Pollutants, April 21–23, 1976; Vienna, Austria.     

Synthesis of a number of N-ω-dimethylaminoalkylmaleimide methiodides

Conclusions A number of N-ω-dimethylaminoalkylmaleimide methiodides was obtained. Institute of Heteroorganic Compounds, Academy of Sciences of the USSR, Moscow. Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 10, pp. 2385–2386, October, 1976.     

In-situ dual-port polarization contrast imaging of Faraday rotation in a high optical depth ultracold 87Rb atomic ensemble

We study the effects of high optical depth and density on the performance of a light-atom quantum interface. An in-situ imaging method, a dual-port polarization contrast technique, is presented. This technique is able to compensate for image distortions due to refraction. We propose our imaging method as a tool to characterize atomic ensembles for high capacity spatial multimode quantum memories. Ultracold dense inhomogeneous rubidium samples are imaged and we find a resonant optical depth as high as 680 on the D1 line. The measurements are compared with light-atom interaction models based on Maxwell-Bloch equations. We find that an independent atom assumption is insufficient to explain our data and present corrections due to resonant dipole-dipole interactions.