Lanthanoid-based ionic liquids incorporating the dicyanonitrosomethanide anion

Anthony Chesman, Mei Yang, Nicolas Spiccia, Glen Berenger Deacon, Stuart Robert Batten, Anja-Verena Mudring

Research output: Contribution to journalArticleResearchpeer-review

26 Citations (Scopus)

Abstract

A series of low-melting-point salts with hexakisdicyanonitrosomethanidolanthanoidate anions has been synthesised and characterised: (C2mim)3[Ln(dcnm)6] (1Ln; 1Ln=1La, 1Ce, 1Pr, 1Nd), (C2C1mim)3[Pr(dcnm)6] (2Pr), (C4C1pyr)3[Ce(dcnm)6] (3Ce), (N1114)3[Ln(dcnm)6] (4Ln; 4Ln=4La, 4Ce, 4Pr, 4Nd, 4Sm, 4Gd), and (N1112OH)3[Ce(dcnm)6] (5?Ce) (C2mim=1-ethyl-3-methylimidazolium, C2C1mim=1-ethyl-2,3-dimethylimidazolium, C4C1py=N-butyl-4-methylpyridinium, N1114=butyltrimethylammonium, N1112OH=2-(hydroxyethyl)trimethylammonium=choline). X-ray crystallography was used to determine the structures of complexes 1La, 2Pr, and 5Ce, all of which contain [Ln(dcnm)6]3- ions. Complexes 1Ln and 2Pr were all ionic liquids (ILs), with complex 3Ce melting at 38.1degrees C, the lowest melting point of any known complex containing the [Ln(dcnm)6]3- trianion. The ammonium-based cations proved to be less suitable for forming ILs, with complexes 4Sm and 4Gd being the only salts with the N1114 cation to have melting points below 100degrees C. The choline-containing complex 5Ce did not melt up to 160degrees C, with the increase in melting point possibly being due to extensive hydrogen bonding, which could be inferred from the crystal structure of the complex.
Original languageEnglish
Pages (from-to)9580 - 9589
Number of pages10
JournalChemistry - A European Journal
Volume18
Issue number31
DOIs
Publication statusPublished - 2012

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