Absorption of Water into Organic Solvents Used for Electrochemistry under Conventional Operating Conditions

摘要

ABSTRACT: Many solvents used for electrochemistry cannbe dried to <1 u0001 10-3nM water content by storing thensolvents over 3 Å molecular sieves in a nitrogen or argonnatmosphere. However, as soon as the solvents are placed innan electrochemical cell, the water content increases signifi-ncantly. Karl Fischer coulometric titrations were conducted onnseveral predried solvents commonly used for electrochem-nistry (acetonitrile, dichloromethane, N,N-dimethylforma-nmide, and dimethyl sulfoxide) in a controlled-humiditynenvironment (30%, 50%, and 70% relative humidity) to determine the rate of moisture uptake into the organic solvents whennused under typical electrochemical conditions (either in an electrochemical cell under a nitrogen atmosphere or in annelectrochemical cell directly exposed to the atmosphere). The results in this study give guidelines for estimating the water contentnof organic solvents under conventional electrochemical operating conditions.