"The distillation and volatility of ionic liquids," by
Martyn J. Earle and 7 others, Nature, 439(7078): 831-4,
16 February 2006.
[Authors' affiliations: Queen's University of Belfast, U.K.;
Universidade Nova de Lisboa, Oeiras, Portugal; NIST,
Boulder, CO]
Abstract: "It is widely believed that a defining
characteristic of ionic liquids (or low-temperature molten salts)
is that they exert no measurable vapour pressure, and hence
cannot be distilled. Here we demonstrate that this is unfounded, and
that many ionic liquids can be distilled at low pressure without
decomposition. Ionic liquids represent matter solely composed of
ions, and so are perceived as non-volatile substances. During the
last decade, interest in the field of ionic liquids has
burgeoned, producing a wealth of intellectual and technological
challenges and opportunities for the production of new chemical and
extractive processes, fuel cells and batteries, and new composite
materials. Much of this potential is underpinned by their presumed
involatility. This characteristic, however, can severely restrict
the attainability of high purity levels for ionic liquids (when they
contain poorly volatile components) in recycling schemes, as well as
excluding their use in gas-phase processes. We anticipate that our
demonstration that some selected families of commonly used aprotic
ionic liquids can be distilled at 200 - 300 degrees C and low
pressure, with concomitant recovery of significant amounts of pure
substance, will permit these currently excluded applications to be
realized."
This 2006 report from Nature was cited 17
times in current journal articles indexed by Thomson
Scientific during November-December 2007. During that two-month
period, only one other chemistry paper published in the last two years
(aside from reviews) attracted a higher number of citations. Prior to
the most recent bimonthly period, citations to the paper have accrued
as follows:
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