Interaction between TEMPO Radicals and Gold Surfaces

Organic radical molecules are, due to their relevance for spintronics and their fundamental interest, studied in mechanically controlled break junctions. It is often assumed that organic radicals are anchored to the gold electrodes by designated linker thiol groups with the radical substituents far from the electrodes. However, the interaction between a radical substituent and gold, in addition to the functional groups designed for anchoring the molecule, could influence the interaction between the whole molecule and the surface. To elucidate a possible influence, we discuss the interaction between a commonly used nitroxyl radical, (2,2,6,6-tetramethylpiperidin-1-yl)oxyl (TEMPO), with gold electrode surfaces by density functional theory methods combined with empirical dispersion corrections. Our results suggest that the interaction between TEMPO and gold is made up of two competitive and complementary contributions: direct binding between the nitroxyl and gold adatoms and dispersion interactions between bulky methyl groups and the surface (which is more pronounced for clean Au(111) surfaces but also prevents direct binding in this case). Importantly, the overall interaction is not negligible and is even comparable to some commonly used anchoring groups (e.g., amino groups). This may have consequences for interpreting the conductance and magnetoresistance data on organic radicals in molecular junctions

Experimental Discovery of Magnetoresistance and Its Memory Effect in Methylimidazolium-Type Iron-Containing Ionic Liquids

The ordering and interactions of charge carriers play a critical role in many physicochemical properties. It is, therefore, interesting to study how a magnetic field affects these physicochemical processes and the consequent behavior of the charge carriers. Here, we report the observation of positive magnetoresistance and its memory effect in methylimidazolium-type iron-containing ionic liquids (ILs). Both the electrical transport and magnetic properties of ILs were measured to understand the mechanism of magnetoresistance behavior and its memory effect. The magnetoresistance effect of [BMIM]­[FeCl4] was found to increase with increasing applied currents. This observed memory effect can be ascribed to the slow order and disorder processes in these ILs due to the large viscosity caused by the interactions among ions

Tuning the Properties at Heterobimetallic Core: Mixed-Ligand Bismuth−Rhodium Paddlewheel Carboxylates

Mixed-ligand heterometallic compounds [BiRh(O2CCF3)4-x(O2CR)x] (R = But, x = 2 (cis); R = Me, Bui, x = 1) have been obtained by gas-phase reactions of bismuth(II) trifluoroacetate with the corresponding rhodium(II) carboxylate. This synthetic approach was found to be very effective for tuning the properties and introduction of chiral ligands at a heterobimetallic core

Tuning the Properties at Heterobimetallic Core: Mixed-Ligand Bismuth−Rhodium Paddlewheel Carboxylates

Mixed-ligand heterometallic compounds [BiRh(O2CCF3)4-x(O2CR)x] (R = But, x = 2 (cis); R = Me, Bui, x = 1) have been obtained by gas-phase reactions of bismuth(II) trifluoroacetate with the corresponding rhodium(II) carboxylate. This synthetic approach was found to be very effective for tuning the properties and introduction of chiral ligands at a heterobimetallic core

Heterometallic Bismuth-Transition Metal Homoleptic β-Diketonates

Bismuth(III) hexafluoroacetylacetonate reacts readily with the first row transition-metal species to produce trinuclear heterobimetallic coordination complexes Bi2M(β-diketonate)8 (M = Mn, Fe, Co, Ni, Cu, Zn). This unique, general approach may offer new possibilities for developing single-source molecular precursors for advance oxide materials

Heterometallic Bismuth-Transition Metal Homoleptic β-Diketonates

Bismuth(III) hexafluoroacetylacetonate reacts readily with the first row transition-metal species to produce trinuclear heterobimetallic coordination complexes Bi2M(β-diketonate)8 (M = Mn, Fe, Co, Ni, Cu, Zn). This unique, general approach may offer new possibilities for developing single-source molecular precursors for advance oxide materials

Heterometallic Bismuth-Transition Metal Homoleptic β-Diketonates

Bismuth(III) hexafluoroacetylacetonate reacts readily with the first row transition-metal species to produce trinuclear heterobimetallic coordination complexes Bi2M(β-diketonate)8 (M = Mn, Fe, Co, Ni, Cu, Zn). This unique, general approach may offer new possibilities for developing single-source molecular precursors for advance oxide materials

Heterometallic Bismuth-Transition Metal Homoleptic β-Diketonates

Bismuth(III) hexafluoroacetylacetonate reacts readily with the first row transition-metal species to produce trinuclear heterobimetallic coordination complexes Bi2M(β-diketonate)8 (M = Mn, Fe, Co, Ni, Cu, Zn). This unique, general approach may offer new possibilities for developing single-source molecular precursors for advance oxide materials

Heterometallic Bismuth-Transition Metal Homoleptic β-Diketonates

Bismuth(III) hexafluoroacetylacetonate reacts readily with the first row transition-metal species to produce trinuclear heterobimetallic coordination complexes Bi2M(β-diketonate)8 (M = Mn, Fe, Co, Ni, Cu, Zn). This unique, general approach may offer new possibilities for developing single-source molecular precursors for advance oxide materials