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

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 betwe en building block donors and accepters, 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 stackin g) and exhibit reversible electrochemical reduction at potentials that are nor. too negative (for promoting the creation of the radical anion). Fortun ately, these same criteria have previously been used to identify one-electr on accepters for the synthesis of CT salt conductors. Although one such mol ecule, 1,4,9,10-anthracenetetrone has not yielded good organic metals in it s reactions with alkali metals or tetrathiafulvalene and related molecules, it was found to give a magnet (T-C = 3 K) in its reaction with decamethylf errocene. Frequency-dependent ac susceptibility measurements indicate glass iness, Significantly, this result shows that nitrile functional groups on t he acceptor are not necessary to obtain magnetic ordering in CT salts. (C) 2001 Elsevier Science Ltd. All rights reserved.