Diarylethene-based photochromic rewritable optical memories: on the possibility of reading in the mid-infrared

It is shown that it is possible to identify the tautomeric form of diarylethene derivatives using a highly selective and very strong infrared absorption band. The 1495 cm−1 band of 1,2-bis-[5′-(4″-methoxyphenyl)-2′-methylthien-3′-yl]perfluorocyclopentene in the closed form is strong enough to fulfil the principal requirements of the technology for read-out systems in optical memories.