Facile Synthesis of Pentacarbonyltungsten(0) Complexes with Oxaphosphirane Ligands

Facile synthesis of tungsten(0) complexes of the type 7a – g (R¹ = C₅Me₅) and 8a – g (R¹ = CH(SiMe₃)₂) using transient Li/Cl phosphanylidenoid tungsten(0) complexes 4 , 5 and carbonyl derivatives 6a – g is reported; furthermore, for all complexes NMR, IR spectroscopic, mass spectrometric investigations and, in addition, single‐crystal X‐ray structures of complexes 7b , d – g and 8b , d are presented.     

Temperature effects on retention and efficiency of butyl and lauryl acrylate porous polymer monoliths in capillary electrochromatography

The development of organic porous polymer monoliths represents an alternative approach to stationary phase design. The use of these materials has helped to rekindle interest in capillary electrochromatography. Although a large number of investigations have explored different monolith recipes, polymerization conditions, and application challenges, few investigations have addressed the fundamentals of this separation mode with this type of material. This study addresses the thermodynamics of the reversed phase retention mechanism on 100% butyl acrylate and 1:3 butyl:lauryl acrylate (volume/volume ratio) porous polymer monoliths used in a capillary electrochromatography mode. Linear van't Hoff plots yield enthalpies of retention of ?3.9 to ?14.3 kJ/mol on two different, but related columns for five selected hydrophobic analytes across a thirty degree temperature range. Minimum plate heights were only moderately impacted over this temperature range.     

Verification of a model to predict the influence of particle inertia and gravity on a decaying turbulent particle-laden flow

In an earlier publication some of the authors presented a theoretical model for the calculation of the influence of particle inertia and gravity on the turbulence in a stationary particle-laden flow. In the present publication the model is extended for application to a decaying suspension. Also a comparison is given between predictions made with the model and experimental data (own data and data reported in the literature) on a decaying turbulent flow with particles in a water tunnel or in a wind tunnel. For most of the experiments a prediction with reasonable accuracy and an interpretation is possible by means of the model.     

Optical nuclear polarization — Targets and sources

The nuclear polarization of³He by optical pumping using discharge lamps is described, as well as attempts (both successful and unsuccessful) to make a polarized³He target. Recent experimental results with a polarized³He target are presented. Experiments to polarize³He using a laser as a pumping light source are described, and the prospects for producing a dense polarized³He target are indicated. The polarization of other nuclei, especially Xe and Kr, by spin transfer from laser polarized alkalis is described.On Leave of Abscence From, Department of Physics, University of Toronto, Toronto, Ontario, Canada, M5S 1A7