In one embodiment, provided are a new class of diarylethene-containing photochromic compounds with the incorporation of silicon- or phosphorus-containing heterocycles into the ethene part of the diarylethene backbone that has been shown to be capable of displaying tunable, robust and thermally stable photochromic properties. Also provided are methods for synthesizing these compounds, as well as uses of these compounds as these compounds may be used as the photochromic layer in an optical recording material and other optical functioning devices.

The invention relates to reactive ionic liquids containing organic cations with groups or substituents which are susceptible to electrochemical reduction and anions obtained from fluoroalkyl phosphates, fluoroalkyl phosphinates, fluoroalkyl phosphonates, acetates, triflates, imides, methides, borates, phosphates and/or aluminates, for use in electrochemical cells, such as lithium ion batteries and double-layer capacitors.