New insight into solid-state molecular dynamics: mechanochemical synthesis of azobenzene/triphenylphosphine palladacycles

Solid-state reactions of dicyclopalladated azobenzenes and triphenylphosphine lead to the thermodynamically favorable bridged complexes. It was demonstrated for the first time that very complex molecular dynamics involving a series of structural transformations is also feasible in the solid state.     

Synthesis of thiophosphoramidates in water: click chemistry for phosphates

An aqueous method for the preparation of N,S-dialkyl thiophosphoramidates is reported. Thiophosphorylation of alkylamines was performed using SPCl(3) in aqueous reaction media, and the resulting thiophosphoramidate-S-anions were S-alkylated with soft electrophiles. Ranges of amines and electrophiles were explored.     

Benzaldehyde lyase catalyzed enantioselective self and cross condensation reactions of acetaldehyde derivatives

Flexible protected 1,3,4-trihydroxy-2-butanone is synthesized in high enantiomeric excesses by using asymmetric homo- and cross- acyloin coupling of aliphatic aldehydes catalyzed by benzaldehyde lyase.     

High-speed two-frame shadowgraphy for velocity measurements of laser-induced plasma and shock-wave evolution

We describe a high-speed, two-frame shadowgraph method for the two-dimensional visualization of an expanding laser-induced plasma and shock wave in two time instances. The developed experimental method uses a 30 ps, green-laser, polarized pulse for the direct and delayed illumination separated by a variable time delay in the range from 300 ps to 30 ns. Since the exposed images of a single event are captured with two CCD cameras, the established method enables velocity measurements of the fast laser-induced phenomena within the nanosecond excitation-laser pulse as well as at later times-when the excitation-laser radiation has already ended.     

Distortion product otoacoustic emission of symphony orchestra musicians before and after rehearsal

The 2f1-f2 distortion product otoacoustic emission (DPOAE) and hearing levels are obtained for 12 normal-hearing symphony orchestra musicians both before and after their rehearsal. The DPOAE fine structures are determined and analyzed according to the character and prevalence of ripples. Hearing levels, DPOAE levels, and DPOAE fine structures before and after rehearsal are similar, indicating that no or marginal temporary change of the state of hearing were caused by the exposure. The data were further compared to similar data for occupationally nonexposed subjects, one group which was age and gender matched, and other two groups of younger individuals (one group with better hearing levels than the other). The data for the age and gender matched group compared well with the musicians data (and the data for the group of better-hearing younger individuals). In general, the analyses of hearing thresholds and DPOAE data thus lead to the same conclusions concerning the state of hearing.     

Entanglement entropy at infinite-randomness fixed points in higher dimensions

The entanglement entropy of the two-dimensional random transverse Ising model is studied with a numerical implementation of the strong-disorder renormalization group. The asymptotic behavior of the entropy per surface area diverges at, and only at, the quantum phase transition that is governed by an infinite-randomness fixed point. Here we identify a double-logarithmic multiplicative correction to the area law for the entanglement entropy. This contrasts with the pure area law valid at the infinite-randomness fixed point in the diluted transverse Ising model in higher dimensions.     

Growth of InP nanostructures via reaction of indium droplets with phosphide ions: synthesis of InP quantum rods and InP-TiO2 composites

InP quantum rods were synthesized via the reaction of monodispersed colloidal indium droplets with phosphide ions. In(0) droplets, which do not act as a catalyst but rather a reactant, are completely consumed. The excess electrons that are produced in this reaction are most likely transferred to an oxide layer at the indium surface. For the synthesis of InP quantum rods with a narrow size distribution, a narrow size distribution of In(0) particles is also required because each indium droplet serves as a template to strictly limit the lateral growth of individual InP nanocrystals. Free-standing quantum rods, 60, 120, or 150 A in diameter, with aspect ratios of 1.6-3.5, and without the residual metallic catalyst at the rod tip, were synthesized from the diluted transparent solution of metallic indium particles. The same approach was used to synthesize InAs quantum rods. A photoactive InP-TiO(2) composite was also prepared by the same chemical procedure; InP nanocrystals grow as well-defined spherical or slightly elongated shapes on the TiO(2) surface.