Article · Wikipedia archive · Last revised Jun 16, 2026

C4mim

C4mim is a shorthand for the 1-butyl-3-methylimidazolium cation, where C4 refers to its butyl group. It is also abbreviated Bmim, and (uncommonly) Bumim. Its salts are usually ionic liquids. 1-Butyl-3-methylimidazolium chloride, also known as [C4mim][Cl] or BMIM-Cl, is usually used for synthesizing salts using this cation. Examples of ionic liquids containing this cation include BMIM-PF6, [Bmim]BF4, and C4mim-FeCl4.

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Wikipedia ↗
1-Butyl-3-methylimidazolium
Kekulé, skeletal formula of a 1-n-Butyl-3-methylimidazolium minor tautomer
Kekulé, skeletal formula of a 1-n-Butyl-3-methylimidazolium minor tautomer source ↗
Identifiers
3D model (JSmol)
ChEBI
ChEMBL
ChemSpider
UNII
  • InChI=1S/C8H15N2/c1-3-4-5-10-7-6-9(2)8-10/h6-8H,3-5H2,1-2H3/q+1
    Key: IQQRAVYLUAZUGX-UHFFFAOYSA-N
  • CCCC[n+]1ccn(C)c1
Properties
C8H15N2+
Molar mass 139.221 g·mol−1
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

C4mim is a shorthand for the 1-butyl-3-methylimidazolium cation, where C4 refers to its butyl group.1 It is also abbreviated Bmim, and (uncommonly) Bumim. Its salts are usually ionic liquids. 1-Butyl-3-methylimidazolium chloride, also known as [C4mim][Cl] or BMIM-Cl, is usually used for synthesizing salts using this cation. Examples of ionic liquids containing this cation include BMIM-PF6, [Bmim]BF4, and C4mim-FeCl4.2

The formation of 1-butyl-3-methylimidazolium chloride from 1-methylimidazole and 1-chlorobutane.3 source ↗

These salts are currently of interest in industry due to their ability to be infinitely recycled and their tendency to participate in solvation at room temperature, possibly making them excellent green solvents.

Structure

C4mim’s structure is based on its parent compound 1-butyl-3-methylimidazole except one electron is removed from its imidazole ring, making it a cation. The stability of C4mim lies in the fact that the resulting electronic vacancy is delocalized across its imidazole ring, despite these electrons being unequally distributed.

See also

See also

References

References

  1. PubChem. "1-Butyl-3-methylimidazolium". pubchem.ncbi.nlm.nih.gov. Retrieved 2026-06-07.
  2. Banerjee, Bubun (21 September 2017). "[Bmim]BF4: A Versatile Ionic Liquid for the Synthesis of Diverse Bioactive Heterocycles". ChemistrySelect. 2 (27): 8362–8376. doi:10.1002/slct.201701700.
  3. Chemiolis (2025-01-17). Making a True Magnetic Liquid. Retrieved 2026-06-07 – via YouTube.
External links