A charge-transfer salt magnet based on a non-cyanocarbon acceptor, 1,4,9,10-anthracenetetrone and decamethylferrocene

Abstract

The charge-transfer (CT) salt approach to the synthesis of magnetic solids has been shown to be an attractive and general route to the creation of new families of molecule-based magnetic solids. It is based on reactions between building block donors and acceptors, where new candidates for the latter role can be readily identified by their shape and by their electrochemical properties. In particular, acceptors should be flat (to facilitate stacking) and exhibit reversible electrochemical reduction at potentials that are not too negative (for promoting the creation of the radical anion). Fortunately, these same criteria have previously been used to identify one-electron acceptors for the synthesis of CT salt conductors. Although one such molecule, 1,4,9,10-anthracenetetrone has not yielded good organic metals in its reactions with alkali metals or tetrathiafulvalene and related molecules, it was found to give a magnet ( T c = 3 K ) in its reaction with decamethylferrocene. Frequency-dependent ac susceptibility measurements indicate glassiness. Significantly, this result shows that nitrile functional groups on the acceptor are not necessary to obtain magnetic ordering in CT salts.