SPIN-CROSSOVER OF A LANGMUIR-BLODGETT-FILM BASED ON AN AMPHIPHILIC IRON(II) COMPLEX

An amphiphilic iron(II) complex [(FeL2)-L-II(NCS)(2), where L is a sub stituted bipyridine] exhibiting a thermal spin-crossover phenomenon ar ound room temperature is chemically unstable at the gas-water interfac e. However, it forms a perfectly stable Langmuir film when formamide-w ater mixtures are used as a subphase. After transfer onto a solid subs trate, a well-defined Langmuir-Blodgett (LB) film was then obtained. I nfrared spectroscopy at variable temperature showed that the spin conv ersion still occurs in this lamellar material. The specific organizati on imposed by the LB technique leads to a surroundings effect demonstr ated, in particular, by thermal cycles. The understanding of this effe ct is crucial to central any thermal or light-induced spin conversion within an LB film.