A 2D Polychloride Network Held Together by Halogen-Halogen Interactions

In a eutectic mixture of two ionic liquids, we have synthesized and crystallized the new polychloride compound [Et4N](2)[(Cl-3)(2)center dot Cl-2] that exhibits a periodic 2D polychloride network acting as an anionic layer. Based on its low melting point and vapor pressure, this compound can be described as a room-temperature ionic liquid. The compound was fully characterized by IR and Raman spectroscopy as well as single-crystal X-ray structure determination. The characterization was complemented by solid-state quantum-chemical calculations confirming the results of the experimental work.