Room-temperature and near-room-temperature molecule-based magnets

Additional members of the family of high- T c molecule-based magnets, Vacceptor] 2. yCH 2Cl 2 have been discovered in which the acceptor is a fluorophenyltricyanoethylene. Varying the number and position of the fluorine substitutions around the phenyl ring results in materials with significantly different magnetic ordering temperatures ( T c's) ranging from 160 to 300 K. Density functional theory calculations were performed on the neutral and anionic forms of the acceptors that reveal modest correlation between T c and three calculated quantities: the gas-phase electron affinity, the dihedral angle between the phenyl ring and the olefin, and the Mulliken spin densities on the nitrogen atoms. The electrochemistry of the acceptors has also been examined.