Crystallographic Insights into Ionic Liquids

Dear Colleagues,

Ionic liquids, a family of salts whose low melting points allow their practical use in the liquid state, are widely known for their rapid and relatively recent emergence into mainstream chemistry. However, examples of ionic liquids have been known for over one hundred years. The spike in interest has been greatly buoyed by crystallography, which has been used to understand the origin of these low melting points and has led to design rules. Thanks in part to clear molecular pictures of ionic liquids from crystallographic studies, so many of these formerly niche, exotic materials have been discovered that they are now considered “designer solvents” because of their nearly unlimited structural variability.

Although ionic liquids are now investigated primarily as solvents and engineering materials, the interface between ionic liquids and crystallography is as important as ever. Crystal structures help us to understand what can often be extremely complex speciation in some ionic liquid systems. The structural variability of ionic liquids has allowed them to be used in crystallizations ranging from the electroplating of metals to the recrystallization of proteins. As the field moves in ever broader directions and relies on an expanding range of subjective terms and definitions, crystals of ionic liquids themselves and of the materials crystallized from them remain a lens that gives a truly objective picture of the inner workings of these materials.

We invite researchers to contribute to this Special Issue, which serves to capture the modern directions in which crystallography (broadly defined) is being used for the understanding and technological application of materials. Potential topics include, but are not limited to

• Crystal structures of ionic liquids (organic, protic, metal-containing, etc.);
• Ionic liquid crystals;
• Ionothermal synthesis;
• Polymorphisms and morphology of molecules crystallized from ionic liquids;
• Crystallization of macromolecules from ionic liquids;
• Ionic liquid–biopolymer interactions in the solid state;
• Crystal structure–property relationships;
• Unconventional characterization techniques (NMR crystallography, impedance spectroscopy, etc.)

Dr. Steven Kelley
Guest Editor

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Crystals is an international peer-reviewed open access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2600 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

• ionic liquids
• crystallization
• polymorphism
• biopolymers
• ionothermal synthesis
• liquid crystals