A catalytic asymmetric nitro-Mannich (aza-Henry) reaction with rare earth metal/alkali metal heterobimetallic catalysts is described. A Yb/K heterobimetallic catalyst assembled by an amide-based ligand promoted the asymmetric nitro-Mannich reaction to afford enantioenriched anti-b-nitroamines in up to 86% ee. Facile reduction of the nitro functionality allowed for efficient access to optically ...

The hydrogen-alkali metal bond is simple and archetypal, and thus an ideal model for studying the nature of highly polar element-metal bonds. Thus, we have theoretically explored the alkali metal hydride monomers, HM, and (distorted) cubic tetramers, (HM)4, with M = Li, Na, K, and Rb, using density functional theory (DFT) at the BP86/TZ2P level. Our objective is to determine how the structure a...

K(+) is a competitive inhibitor of the uptake of the other alkali metal cations by yeast. Rb(+) is a competitive inhibitor of K(+) uptake, but Li(+), Na(+), and Cs(+) act like H(+). At relatively low concentrations they behave as apparent noncompetitive inhibitors of K(+) transport, but the inhibition is incomplete. At higher concentrations they inhibit the remaining K(+) transport competitivel...

Nanowires are formed by indenting and subsequently retracting two pieces of sodium metal. Their cross section gradually reduces upon retraction and the diameters can be obtained from the conductance. In previous work we have demonstrated that when one constructs a histogram of diameters from large numbers of indentation-retraction cycles such histograms show a periodic pattern of stable nanowir...

An overview is presented of classic and more recent applications of liquid chromatography for the analysis of metal species. The different approaches involving ion-exchange, ion-pair, and chelation separation mechanisms are discussed as well as the new philosophy of simply removing interferents before specific detections of metal ions (alkali and alakaline earths, rare earths, heavy and transit...

Alexey V. Gorshkov,1,4 Salvatore R. Manmana,2 Gang Chen,2 Eugene Demler,3,4 Mikhail D. Lukin,3,4 and Ana Maria Rey2,4 1Institute for Quantum Information, California Institute of Technology, Pasadena, California 91125, USA 2JILA, National Institute of Standards and Technology and University of Colorado, Boulder, Colorado 80309-0440 and Department of Physics, University of Colorado, Boulder, Colo...

Matrix isolation infrared (IR) studies have been carried out on the vaporisation of the alkali-metal azides MN3 (M = Na, K, Rb and Cs). The results show that under high vacuum conditions, molecular KN3, RbN3 and CsN3 are present as stable high-temperature vapour species, together with variable amounts of nitrogen gas and the corresponding metal atoms. The characterisation of these molecular azi...

ABSTRACf. We present the photoelectron (photodetacment) spectra of K2:-19 recorded using 2.540 eV photons. These spectra are highly structured, providing a wealth of information about the electronic structure of alkali metal clusters, including adiabatic electron affinities and electronic spliuings for each size. Spectral assignments have been made with guidance from theory. For the smaller clu...

Bis(trimethylsilyl)amide derivatives of the group 1 elements (Li, Na, K) are competent pre-catalysts for the dehydrocoupling of Me2NH·BH3 via the formation of intermediates containing [H3BNMe2BH2Me2N](-) anions.

A remarkable orbital quadrupole magnetic resonance, so-called twist mode, is predicted in alkali metal clusters where it is represented by Ipi = 2(-) low-energy excitations of valence electrons with strong M2 transitions to the ground state. We treat the twist by both macroscopic and microscopic ways. In the latter case, the shell structure of clusters is fully exploited, which is crucial for t...