Purification of gaseous CO from Fe(CO)(5) traces formed in steel storage cylinders

High purity gaseous CO stored in a steel tank contains a volatile iron carb onyl compound that easily contaminates electrochemical samples saturated wi th CO. The impurity yields a voltammetric reduction peak at -2.0 V in non-a queous solvents (acetonitrile, acetone and tetrahydrofurane) and IR absorpt ion at 2024 and 2001 cm(-1) characteristic of metal carbonyls. This impurit y is Fe(CO), and can be removed efficiently by bubbling CO through aqueous NaOH solution. This purification procedure is adequate for the electrochemi cal studies of metal carbonyls under CO atmosphere. Failure to remove this volatile impurity may lead to misinterpretation of electrocatalytic and lig and substitution reactions. (C) 2001 Elsevier Science B.V. All rights reser ved.