Catalysis of Organic..

274 Acidic Ionic Liquidssites for HCl exist for each dinuclear Al-species and that four of the six sites are13much more acidic than the remaining two sites. Subsequent C-NMR measurementsn=1.5 n=2abpeak height1.E+001.E+001.E+001.E+008.E-016.E-016.E-014.E-014.E-01cf(x)1f(x)2f(x)3f(x)4sumf(x)1f(x)2f(x)3f(x)4sumpeak heightpeak height1.20E+001.20E+001.00E+008.00E-018.00E-016.00E-016.00E-014.00E-014.00E-01df(x)1f(x)2f(x)3f(x)4sumf(x)1f(x)2f(x)3f(x)4sum2.E-012.00E-012.E-010.E+000.00E+00 5.00E-05 1.00E-04 1.50E-04 2.00E-040.E+00chemical shift, ppm0.00E+00 5.00E-05 1.00E-04 1.50E-04chemical shift, ppm2.00E-010.00E+000.00E+00 5.00E-05 1.00E-04 1.50E-040.00E+00chemical shift, ppm0.00E+00 5.00E-05 1.00E-04 1.50E-04chemical shift, ppmIncreasing downfield, chemical shiftIncreasing downfield, chemical shiftFigure 3. Observed 27 Al-NMR spectrum for IL derived from [n-BuMIM] + [Al n Cl 3n+1 ] - ,a: n = 3/2; b: n = 2; Predicted 27 Al-NMR spectrum for IL derived from [n-BuMIM] +[Al n Cl 3n+1 ] - ,c: n= 3/2; b: n = 2.13of 2- C-acetone in the BMIM-IL confirmed the presence of six acidic protons (Fig.4) showing chemical shifts of 246.7 to 239.8 ppm. The chemical shifts of 2- 13 C-acetone in contact with sulfuric acid and triflic acid confirmed that labeled acetonechemical shifts greater than 245 ppm are super acidic. (13)Figure 4 – a: 15.3 ppm(245)Figure 4 – b: 14.3 ppm(242)