Search results for "carbon"

Physiologische Erythrozyten-Protektionslösung (PEP)

2001

Iod-induzierte stereoselektive Carbocyclisierungen – Beispiele für eine breit anwendbare, neue Methode zur Synthese von Cyclohexan- und -hexen-Deriva…

1988

Linear Organic Carbonates

2003

The most common and successful method for producing organic carbonates, including polycarbonates, has been based for long time on the reaction between an alcohol or phenol and phosgene. The existing strict environmental regulations and the expanding market for organic carbonates do not assure that this technology can continue to have a leading role in this area, due to the inherent riskfulness of the processes. The market expansion of dimethyl carbonate (DMC), diphenyl carbonate (DPC), and bisphenol A polycarbonate (BPA-PC) is a reality, finding its driving force from the industrialization of alternative routes by EniChem (Italy) and UBE (Japan). This favorable situation can be foreseen for…

Nano‐Powdered Calcium Carbonate Reference Materials: Significant Progress for Microanalysis?

2019

Isolation, separation and quantification of metabolites of the carcinogenic polycyclic aromatic hydrocarbon dibenz(a,h)anthracene

1986

Ein Mikro-Atemstromventil für spontan atmende narkotisierte Kleintiere - A Respiratory Micro-Valve for Spontaneously Breathing Anaesthetized Small An…

1994

For the accurate functional analysis of the gas exchange in the lungs or evaluation of artificial oxygen carriers in spontaneously breathing anaesthetized small animals, we developed a new respiratory micro-valve. The body of the valve is made of aluminium, and the flaps are made of silicone rubber. The maximum flow rate in a rat measured with a pneumotachograph and the micro-valve was an average of 19.9 ml/s during inspiration, and 17.8 ml/s during expiration. The pressure measured in the tracheal tube was -0.85 during inspiration, and +0.39 cm H2O during expiration; the end-expiratory pressure in the tube was zero. In two experiments with anaesthetised rats lasting 4-5 hours, ventilation,…

Conformational study of methyl esters of some aliphaticerythro- andthreo-dichlorocarboxylic acids

1984

The average conformations of methyl esters of some aliphatic erythro- and threo-dichlorocarboxylic acids in dilute carbon tetrachloride solutions have been determined from the vicinal proton–proton coupling constants and 1H NMR shifts. The 13C shift differences between the erythro and threo forms are compared and discussed with regard to the differences in the average conformations.

13C NMR spectroscopic study of diphenyl ether and 28 of its polychlorinated derivatives

1993

The 13 C NMR chemical shifts and coupling constants for diphenyl ether and 28 environmentally interesting polychlorinated diphenyl ethers were measured and analysed

Selectively Functionalized Constrained Polyazamacrocycles: Building Blocks for Multifunctional Chelating Agents

2013

A new class of cross-bridged and side-bridged 1,4,7,10-tetraazacyclotridecanes (homocyclens) bearing an aminomethyl pendant arm on the carbon skeleton has been prepared. The regioselectivity of the quaternization of the bis-aminal intermediates is discussed on the basis of X-ray diffraction and NMR experiments. These new polyazamacrocycles are valuable precursors of bifunctional chelating agents for applications in nuclear medicine.

Calix Crowns Derived from para-Bridged Calix[4]arenes

2000

Two calix[4]arenes, bridged by aliphatic chains of five and eight carbon atoms spanning two opposite para positions, have been converted into their 1,3-crown ether derivatives by reaction with tetraethylene and pentaethylene glycol ditosylates. Of the two possible 1,3-crown derivatives, only the formation of those isomers is observed in which the phenolic units connected at the para positions are etherified. This has been established in one case by a single-crystal X-ray analysis. Preliminary results for the extraction of selected alkali and alkaline-earth metals are reported.