Spontaneous transfer of phospholipid-coated oil-in-oil and water-in-oil micro-droplets through an oil/water interface

We studied the evolution of oil-in-oil (O/O) and water-in-oil (W/O) phospholipid-coated micro-droplets at an oil/water interface. We found that, in both cases, micro-droplets spontaneously transferred from the oil phase to the water phase. O/O micro-droplets transformed into oil-in-water micro-droplets, while W/O micro-droplets led to the formation of liposomes.     

Die elektronenstruktur des arsenins (arsabenzols)

The electronic structure of arsenin has been investigated using an extended CNDO/2 approach. Orbital energies, ionization potentials, orbital and total electron density contour maps are given and compared with those of phosphorin and pyridine.     

Decomposition of chemically activated ethyltrimethylgermane the arrhenius A-factors for rupture of group IVA—methyl bonds

The decomposition rate of chemically activated ethyltrimethylgermane from the reaction ¹CH₂ + (CH₃)₄Ge, where ¹CH₂ was produced from diazomethane photolysis at 3660 Å, is 8.6 × 10⁵ sec^?1. This result combined with RRKM theory and critical energy estimates yields an Arrhenius A factor of log[A (sec^?1)/methyl] = 14.7 ± 0.8 for methyl rupture from germanium. Log A values for methyl rupture from carbon, silicon, and germanium linearly correlate with the vibrational-rotational entropies of the corresponding tetramethyls. Extrapolation predicts log[A (sec^?1)/methyl] = 14.4 and 14.3 for methyl rupture from tin and lead, respectively.     

On the applicability of slow passage EPR relaxation theories to saturation curves for trapped electrons in organic glasses

It is shown that the experimental microwave power saturation curves for trapped electrons in organic glasses do not fit the simple paramagnetic relaxation theories developed for inhomogeneous lines in the absence of magnetic field modulation. To understand experimental saturation data obtained in the presence of modulation, it is suggested that theoretical treatments must include magnetic field modulation effects.     

Ab initio direct dynamics trajectory simulation of C2H5F-->C2H4 + HF product energy partitioning

Direct dynamics classical trajectory simulations were performed to study product energy partitioning in C(2)H(5)F-->C(2)H(4)+HF dissociation. The intrinsic reaction coordinate potential energy curve, reaction energetics, and transition state (TS) properties were calculated for this reaction at different levels of electronic structure theory, and MP2/6-31G( *) was chosen as a meaningful and practical method for performing the direct dynamics. The trajectories show that the HF bond, uncoupled from the other degrees of freedom, is formed within the first 10 fs as the system moves from the TS towards products. The populations of the HF vibration states, determined from the simulations, decrease monotonically as found from experiments. However, the simulation's populations for the low and high energy vibration states are larger and smaller, respectively, than the experimental results. The HF rotational temperature found from the simulations is in agreement with experiment. Increasing the TS's excess energy gives higher rotational temperatures for both C(2)H(4) and HF. Energy is partitioned to the products from both the excess energy in the TS and the potential energy release in the exit channel. Partitioning from these two energy sources is distinguished by varying the TS's excess energy. An analysis of the simulation's energy disposal shows that the fractions of the excess energy partitioned to relative translation, C(2)H(4) vibration, C(2)H(4) rotation, HF vibration, and HF rotation, are 0.17, 0.64, 0.076, 0.067, and 0.046, respectively, and are in good agreement with previous simulations on empirical potentials and experiments. The partitioning found for the potential energy release is 81%, <0.05%, 5%, 11%, and 3% to relative translation, C(2)H(4) vibration, C(2)H(4) rotation, HF vibration, and HF rotation. This result is substantially different than the deduction from experiments, which summarizes the partitioning as 20%, 45%, 24%, and <12% to relative translation, C(2)H(4) vibration+rotation, HF vibration, and HF rotation. Possible origins of the difference between the simulations and experiments in the release of the potential energy is discussed.     

Phonon autoecho in bismuth and antimony single crystals

Phonon autoecho is observed upon pumping Bi and Sb semimetals with ultrashort high-energy laser pulses. The autoecho is manifested as a revival of reflection oscillations generated by an A_1g coherent phonon after their complete disappearance. The phenomenon of phonon autoecho offers decisive evidence of the nonclassical character of the state of the crystal lattice that is accomplished in pumping-probing experiments by femtosecond laser pulses.