Synthesis and optical properties of 1-alkyl-3-methylimidazolium lauryl sulfate ionic liquids.
We report the synthesis of a new series of imidazolium-based halogen-free ionic liquids 1-alkyl-3-methylimidazolium lauryl sulfates. By reacting 1-methylimidazole (MIM) with butyl, hexyl, octyl, and decyl bromides and exchanging bromide ion with lauryl sulfate anion, a series of ionic liquids [RMIM][C(12)H(25)OSO(3)] were produced. The high purity of these ionic liquids was verified with (1)H-NMR, (13)C-NMR, FT-IR and mass spectrometry (MS), demonstrating the effectiveness of this synthetic approach. Solubility test of these ionic liquids showed that they are soluble in most organic solvents except nonpolar solvents such as hexane and cyclohexane. The optical properties of [BMIM]Br and [BMIM][C(12)H(25)OSO(3)], where B refers to butyl, were examined. Both ionic liquids absorbed light in the UV region, yet essentially no absorption was recorded beyond 450 nm. Furthermore, both ionic liquids showed excitation wavelength-dependent fluorescence behavior. As an example, with an excitation wavelength of 360 nm, [BMIM][C(12)H(25)OSO(3)] showed an emission band maximum at 447 nm. Increasing the excitation wavelength to 440 nm, the emission band maximum was shifted to approximately 500 nm.
Obliosca
Judy M
JM
Department of Chemistry, National Tsing Hua University, Hsinchu, Taiwan.
Arco
Susan D
SD
Huang
Michael H
MH
Chem Commun (Camb). 2005 Jan 7;(1):83-5
15614380
J Phys Chem B. 2005 May 12;109(18):9148-53
16852088
J Phys Chem B. 2006 Jul 20;110(28):13704-16
16836314
J Am Chem Soc. 2004 Mar 17;126(10):3026-7
15012113
J Phys Chem B. 2005 Aug 4;109(30):14445-8
16852818
J Am Chem Soc. 2004 Apr 28;126(16):5036-7
15099064
Chem Rev. 1999 Aug 11;99(8):2071-2084
11849019
J Phys Chem B. 2006 Jun 15;110(23):11025-8
16771357
Chem Rev. 2002 Oct;102(10):3667-92
12371898
Chem Commun (Camb). 2001 Dec 7;(23):2399-407
12239988