An improved acousto-optical light modulator

A simplification of the conventional acousto-optical light modulator and deflector arrangement is presented. The collimating lens, modulator, and focusing lens are combined into one unit — a modulator whose faces are curved rather than plane.     

Reactions of TIN(II) halides with compounds containing a transition metalcarbon σ-bond

Tin(II) chloride inserts into the ironcarbon σ-bond in MeFe(CO)₂Cp (Cp = cyclopentadienyl), in refluxing methanol or THF, to give MeClSnFe(CO)₂- Cp and traces of Cl₃SnFe(CO)₂Cp, but, with EtFe(CO)₂Cp, a mixture of the insertion product, Cl₃SnFe(CO)₂Cp, and Cl₂Sn[Fe(CO)₂Cp]₂ is formed. Insertion of tin(II) chloride was not observed for MeMo(CO)₃Cp and MeMn(CO)₅; in these reactions, and in those between tin(II)_bromide and MeFe(CO)₂Cp, EtFe(CO)₂Cp and Memo(CO)₃Cp, mixtures of halo—metal carbonyls and halotin—metal carbonyls result.     

Improved preparative electrochromatography column design

Improved chromatography column fittings were developed for the efficient and reliable application of an electric field to a preparative chromatography column (a process termed electrochromatography). The improved fittings contained electrodes in close proximity to the column packing media and allowed uniform electric fields to be applied. Membranes in the fittings prevented mixing of the electrode and the column eluent buffers. The membranes prevented gases and electrolytic products generated in the electrode chamber from entering the column eluent buffer. An electrode buffer solution was pumped through the electrode chamber to a large external container. The circulation of buffer through the electrode chamber removed the gases and electrolytic products and ensured a uniform electric field by helping to maintain a constant buffer composition. The membranes prevented macromolecules being separated on the column from coming in contact with the electrodes.     

Os(VIII)-catalysed oxidation of sulfides by sodium salt of N-chlorobenzenesulfonamide

Catalytic activity of Os(VIII) in the oxidation of some twenty organic sulfides with sodium salt of N-chlorobenzenesulfonamide (CAB) has been investigated in alkaline (pH8.7) t-butanol–water (1:1 v/v) medium. Significant retarding influence of [OH⁻] on the reactivity is exhibited. The catalysed reaction is strongly accelerated in the presence of Hg(II). Imperfections are observed in the linear Hammett relationship in the case of –NO₂ substituents.     

Capillary electrophoretic determination of carboxyhemoglobin concentrations in postmortem blood samples

The use of capillary electrophoresis (CE) as an alternative to existing methods of quantitation of carbon monoxide (CO) in hemoglobin from postmortem blood samples is presented. The isolation of heme (the portion of the hemoglobin molecule in which CO binding takes place) from hemoglobin is described. Reduced (containing no gas molecules) heme and CO-heme isolated from hemoglobin standards were successfully separated using CE. Heme and CO-heme were also isolated from blood samples of accident victims and analyzed using CE. A quantifiable difference in the CO-heme signals from blood samples containing fatal and nonfatal levels of CO was observed.     

Modification of the electrokinetic properties of reversible electrophoresis gels for the separation and preparation of DNA

The effect of adding linear polymers to a novel reversible electrophoretic was measured. Reversible gels are formed using the polyanionic carbohydrate polymer, gellan gum. Gellan gum forms strong stable gels in the presence of divalent cations or diamines. The gels are reversible (return to solution) by changing the ionic environment or pH. Gellan gum is an anionic polymer, and the electrophoresis gels have considerable electroosmotic flow (EOF) toward the negative electrode. We measured the EOF in gellan gum electrophoresis gels as a function of gel concentration, buffer composition, and linear polymer additive. The linear polymers used in this study were polyethylene oxide and hydroxyethyl cellulose. Both polymers reduced EOF in the gels, in a manner dependent on molecular weight. Polymers with high molecular weight were more effective at reducing EOF. The addition of polymers increased the resolution of low molecular weight DNA. Native gellan gum resolved DNA from approx 50,000 to 1000 bp. Addition of the polymers resolved DNA down to approx 50 bp, in some instances. The influence of the polymers on circular plasmid DNA was also investigated. Addition of high molecular weight polyethylene oxide reduced the electrophoretic mobility of the nicked circular form compared to the supercoiled form.     

A kinetic and spectroscopic study of the interaction between a M(CO)5 (M=Cr, W) fragment and ethyl diazoacetate

The reaction between Cr(CO)₅[C₆H₆] and ethyl diazoacetate (EDA) has been studied using the technique of laser flash photolysis. Results indicate that the Cr(CO)₅ fragment reacts very rapidly with the EDA ligand. Low temperature spectroscopic studies suggest that in the case of W(CO)₅, and by analogy also in the case of Cr(CO)₅, the initial adduct between the pentacarbonyl fragment and EDA is one where the oxygen atom of the diazocarbonyl ligand is bound to the metal center. This kinetic product is then converted to a thermodynamically favored complex which is tentatively assigned as the nitrogen bound W(CO)₅-EDA complex that appears to be stable at r.t.