Crown ethers have the remarkable property of recognizing and binding specific metal cations in complex mixtures. We propose to combine molecular recognition with molecular electric conductance. The question we address is: can the event of binding a cation be sensed by a change in conductance? Specifically, we study a short molecular wire (MW) containing a crown-6 molecule connected via sulfur a...

Fine and ultrafine Nd-Fe-B particles have been obtained from metallic cation reduction by borohydride ions both in water and microemulsions. In this way amorphous particles of different sizes ranging from 4-50 nm to 100-400 nm can be obtained. In this work we will report on the kinetics of the growth of the particles studied by stopped-flow with UV-Vis detection. Quantum effects are suggested f...

In a theoretical study of a "defect perovskite" structure of stoichiometry AeTiO(2) (AE = alkaline earth metal, Be, Mg, Ca, Sr, and Ba), we find substantial Ti-Ti bonding tuned by the size of the Ae(2+) cation. The bonding is one-dimensional, partially sigma, partially pi. These formal d(2) systems are expected to be nonmagnetic and metallic. A competing (for same Ae) structural alternative, an...

A simple method was developed for the reversible and selective modification of metallic and large diameter semiconducting SWCNTs in [BMIM]PF(6) ionic liquids by adding certain anion surfactants. The electronic band structure of SWCNTs can be controlled and tuned over a range by varying the surfactants used and their concentrations. A charge transfer "cation- product operator" complex model was ...

Epitaxial heterostructures composed of complex correlated metal oxides, grown along specific crystallographic orientations, offer a route to investigating emergent phenomena such as topological states and spin liquids through geometrical lattice engineering. A2Ru2O7 pyrochlore ruthenates, in particular, exhibit metal–insulator transition with varying A cation, whose mechanism is not fully under...

In the past five years, over 20 types of cyclo-N5− energetic materials (EMs) have been successfully synthesized. Metallic EMs exhibit higher density and performance compared to non-metallic EMs. However, mechanisms for such metallic remain unexplored. Herein, we performed a thorough quantum chemistry study on mechanistic pathway trapped by metal cations in four EMs: [Na(H2O) (N5)] · 2H2O, [M(H2...

Quaternary ammonium compounds, effective as sanitizing agents for food plant equipment under certain conditions, are not well suited as sanitizers for water of high mineral content. Mueller and Seeley (1951) have demonstrated under controlled conditions that various metallic cations can decrease the germicidal action of a quaternary in solution. Knowledge of how such interference takes place co...

Among the different synthesis approaches to colloidal nanocrystals, a recently developed toolkit is represented by cation exchange reactions, where the use of template nanocrystals gives access to materials that would be hardly attainable via direct synthesis. Besides, postsynthetic treatments, such as thermally activated solid-state reactions, represent a further flourishing route to promote f...