TY - JOUR
T1 - Water-induced accelerated ion diffusion
T2 - Voltammetric studies in 1-methyl-3-[2,6-(S)-dimethylocten-2-yl]imidazolium tetrafluoroborate, 1-butyl-3-methylimidazolium tetrafluoroborate and hexafluorophosphate ionic liquids
AU - Schröder, U.
AU - Wadhawan, J. D.
AU - Compton, R. G.
AU - Marken, F.
AU - Suarez, P. A.Z.
AU - Consorti, C. S.
AU - De Souza, R. F.
AU - Dupont, J.
PY - 2000/12/1
Y1 - 2000/12/1
N2 - The electrochemical properties of the room temperature ionic liquids 1-butyl-3-methylimidazolium tetrafluoroborate (BMIM+BF4-), 1-butyl-3-methylimidazolium hexafluorophosphate (BMIM+PF6-) and 1-methyl-3-[2,6-(S)-dimethylocten-2-yl]imidazolium tetrafluoroborate (MDIM+BF4-) as solvents have been studied using micro-samples, with a volume of 10 μL, of the ionic liquids under vacuum conditions and under conditions with controlled gas and moisture supplies. The impact of water - absorbed into the ionic liquid in a controlled manner from the gas phase - on the voltammetry of dissolved redox systems and on the accessible potential window of the ionic liquids was investigated. The diffusion coefficients for three representative redox systems, the oxidation of neutral N,N,N′,N′-tetramethyl-p-phenylenediamine (TMPD), the reduction of cationic methyl viologen (MV2+) and reduction of anionic hexacyanoferrate(III), Fe(CN)63-), have been determined as a function of the water content of the ionic liquids. Water is shown to have a much more dramatic acceleration effect on the diffusion of the ionic compounds compared to its effect on neutral species in ionic liquids. A model based on nanoscale structural features of wet ionic liquid materials is proposed. The novel methodology, which employs redox-active compounds dissolved or partitioned in microdroplets of ionic liquid, uses conditions suitable for the study of ionic liquids for applications in electrochemical gas phase reactors and gas sensor systems.
AB - The electrochemical properties of the room temperature ionic liquids 1-butyl-3-methylimidazolium tetrafluoroborate (BMIM+BF4-), 1-butyl-3-methylimidazolium hexafluorophosphate (BMIM+PF6-) and 1-methyl-3-[2,6-(S)-dimethylocten-2-yl]imidazolium tetrafluoroborate (MDIM+BF4-) as solvents have been studied using micro-samples, with a volume of 10 μL, of the ionic liquids under vacuum conditions and under conditions with controlled gas and moisture supplies. The impact of water - absorbed into the ionic liquid in a controlled manner from the gas phase - on the voltammetry of dissolved redox systems and on the accessible potential window of the ionic liquids was investigated. The diffusion coefficients for three representative redox systems, the oxidation of neutral N,N,N′,N′-tetramethyl-p-phenylenediamine (TMPD), the reduction of cationic methyl viologen (MV2+) and reduction of anionic hexacyanoferrate(III), Fe(CN)63-), have been determined as a function of the water content of the ionic liquids. Water is shown to have a much more dramatic acceleration effect on the diffusion of the ionic compounds compared to its effect on neutral species in ionic liquids. A model based on nanoscale structural features of wet ionic liquid materials is proposed. The novel methodology, which employs redox-active compounds dissolved or partitioned in microdroplets of ionic liquid, uses conditions suitable for the study of ionic liquids for applications in electrochemical gas phase reactors and gas sensor systems.
UR - http://www.scopus.com/inward/record.url?scp=0034533995&partnerID=8YFLogxK
U2 - 10.1039/b007172m
DO - 10.1039/b007172m
M3 - Article
AN - SCOPUS:0034533995
SN - 1144-0546
VL - 24
SP - 1009
EP - 1015
JO - New Journal of Chemistry
JF - New Journal of Chemistry
IS - 12
ER -