Luminescent Ln-Ionic Liquids beyond Europium

Area of Science:

• Materials Science
• Inorganic Chemistry
• Photochemistry

Background:

• Europium is the dominant lanthanide in luminescence research due to its efficient sensitization and long decay times.
• Other lanthanides offer unique luminescence colors, sensitivities, and probing capabilities crucial for diverse applications.
• Existing literature often sidelines non-europium lanthanides, despite their significant potential.

Purpose of the Study:

• To comprehensively review and highlight the published work on non-europium lanthanide luminescence in ionic liquids.
• To categorize existing research into two main types: lanthanide compounds in ionic liquids and lanthanide-based ionic liquids.
• To analyze future trends and promising research avenues, including ionogels.

Main Methods:

• Systematic literature search on "ionic liquids", "luminescence", and "lanthanide" in Web of Knowledge.
• Analysis and categorization of approximately 260 relevant entries, focusing on non-europium lanthanides.
• Review of studies involving lanthanide compounds dissolved in ionic liquids and lanthanide-based ionic liquids.

Main Results:

• Europium dominates the field, with other lanthanides frequently studied in a subordinate role.
• Research is divided into two primary categories: lanthanide compounds in ionic liquids and lanthanide-based ionic liquids.
• The review consolidates information on diverse lanthanide applications beyond europium.

Conclusions:

• Non-europium lanthanides possess significant, yet underexplored, potential in ionic liquid-based luminescence.
• Future research should focus on these alternative lanthanides and emerging areas like ionogels for advanced applications.
• This review provides a concise overview and roadmap for future investigations in lanthanide luminescence within ionic liquids.