Integrated Calendar

Organic-based materials exhibiting the technologically important property of bulk magnetism have been prepared and studied in collaboration with many research groups worldwide frequently exhibit supramolecular extended 3-D structures. These magnets are prepared via conventional organic synthetic chemistry methodologies, but unlike classical inorganic-based magnets do not require high-temperature metallurgical processing. Furthermore, these magnets are frequently soluble in conventional solvents (e. g., toluene, dichloromethane, acetonitrile, THF) and have saturation magnetizations more than twice that of iron metal on a mole basis, as well as in some cases coercive fields exceeding that of all commercial magnets (e.g., Co5Sm). Also several magnets with critical temperatures (Tc) exceeding room temperature have been prepared. In addition to an overview of magnetic behavior, numerous examples of structurally characterized magnets made from molecules will be presented. Our groups has discovered 8 families of molecule-based magnets, mostly organic-based, and have significantly contributed to an eight family based upon the Prussian blue structure. Four examples magnetically order above room temperature and as high at 127 oC. These will include [MIII(C5Me5)2][A], [MnIII(porphyrin)][A] (A = cyanocarbon etc. electron acceptors) as well as M[TCNE]x, which for M = V is a room temperature magnet that can be fabricated as a thin film magnet via Chemical Vapor Deposition (CVD) techniques. A newer class of magnets of [Ru2(O2CR)4]3[M(CN)6] (M = Cr, Fe; R = Me, t-Bu) composition will also discussed. For R = Me an interpenetrating, cubic (3-D) lattice forms and the magnet exhibits anomalous hysteresis, saturation magnetization, out-of-phase, "(T), AC susceptibility, and zero field cooled-field cooled temperature-dependent magnetization data. This is in contrast to R = t-Bu, which forms a layered (2-D) lattice. Additionally, new magnets possessing the nominal Prussian blue composition, M'[M(CN)6]x and (Cation)yM'[M(CN)6], but not their structure, will be described. The organic chemistry crucial to designing and preparing organic-based magnets will be discussed.

Much like humans, animals may choose to initiate behavior based on their "internal state" rather than as a response to external stimuli alone. The neuronal underpinnings responsible for generating this ‘internal state’, however, remain elusive. The parasitoid jewel wasp hunts cockroaches to serve as a live food supply for its offspring. The wasp stings the cockroach in the head and delivers a neurotoxic venom cocktail directly inside the prey’s cerebral ganglia to apparently ‘hijack its free will’. Although not paralyzed, the stung cockroach becomes a living yet docile ‘zombie’ incapable of self-initiating walking or escape running.
We demonstrate that the venom selectively depresses the cockroach’s motivation or ‘drive’ to initiate and maintain walking-related behaviors, rather than inducing an overall decrease in arousal or a ‘sleep-like’ state. Such a decrease in the drive for walking can be attributed to a decrease in neuronal activity in a small region of the cockroach cerebral nervous system, the sub-esophageal ganglion (SEG). Specifically, we have used behavioral, neuro-pharmacological and electrophysiological methods to show that artificial focal injection of crude milked venom or procaine into the SEG of non-stung cockroaches decreases spontaneous and evoked walking, as seen with naturally-stung cockroaches. Moreover, spontaneous and evoked neuronal spiking activity in the SEG, recorded with an extracellular bipolar microelectrode, is markedly decreased in stung cockroaches as compared with non-stung controls. By injecting a venom cocktail directly into the SEG, the parasitoid Jewel Wasp selectively manipulates the cockroach’s motivation to initiate walking without interfering with other non-related behaviors.