(a) Give three examples of commonly used ionicliquids. What general properties make ionic...

(a) Give three examples of commonly used ionic

liquids. What general properties make ionic liquids attractive in ‘green chemistry’? Are the properties of the liquid itself all that determines whether the ionic liquid is environmentally friendly?

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(b) The compound shown below was treated with one equivalent of NaOH in methanol to give the ionic liquid X:

The positive mode electrospray mass spectrum of X exhibits a peak at mjz 126. Compound X reacts with chloroauric acid, HAuC14, to give a salt, Y, which contains two square planar Au(III) environments. The anion in Y has D4h symmetry. The 'H NMR spectrum of a DMSO-d6 solution of Y exhibits the following signals: 8/ppm 9.07 (s, 1H), 7.92 (br, 2H), 7.74 (overlapping signals, 2H), 4.38 (t, 2H), 3.86 (s, 3H), 3.34 (m, 2H). The eiectrospray mass spectrum of Y shows peak envelopes at mjz 428 and 126 (positive mode), and 339 (negative mode). The peak envelope at mjz 339 consists of four peaks, and that at mjz exhibits three dominant peaks al mjz 428, 429 and 432. Identify X and Y, and interpret the data. Rationalize the appearance of the mass spectra.

[Data: B. Ballarin et al. (2010) Inorg. Chim. Ada, vol. 363, p. 2055]