Anisotropic bulletlike emission of terminal ethynyl fragment ions: ionization of ethynylbenzene-d under intense femtosecond laser fields

The authors investigated Coulomb explosions of ethynylbenzenes under intense femtosecond laser fields. Deuteration on the edge of the triple bond gave information about specific fragment emissions and the contribution of hydrogen migration. Some fragments not resulting from migration were emitted in the direction of laser polarization. These were ethynyl fragment ions (D(+), CD(+), C(2)D(+), and C(3)D(+)). Although two bonds have to be cleaved to produce C(3)D(+), the rigid character of the triple bond was maintained in the Coulomb explosion process. In contrast, fragment ions, which are formed after single or double hydrogen migration, showed isotropic emissions with distinct kinetic energies. The character of the substituents has been found to hold even under strong laser light fields where violent fragmentation took place. The ethynyl parts were emitted like bullets from the molecular frame of ethynylbenzene despite the explosion into pieces of the main body of benzene ring.     

Vapour–liquid equilibrium for the systems diethyl sulphide + 1-butene, +cis-2-butene, +2-methylpropane, +2-methylpropene, +n-butane, +trans-2-butene

Isothermal vapour–liquid equilibrium was measured for the systems of diethyl sulphide + 1-butene, +cis-2-butene, and +2-methylpropene at 312.6 K, diethyl sulphide + n-butane was measured at 317.6 K, diethyl sulphide + trans-2-butene at 317.5 K, and diethyl sulphide + 2-methylpropane at 308.0 K. The pressure–temperature–total composition data were converted into pressure–temperature–liquid–vapour composition data using the method of Barker. Error estimates are provided for each variable. The isothermal parameters for the Wilson, NRTL and UNIQUAC activity coefficient models were regressed. The measurements were compared with the predictions by COSMO segment activity coefficient (COSMO-SAC) and UNIFAC.     

Multi-symplectic wavelet splitting method for the strongly coupled Schrodinger system

<正>We propose a multi-symplectic wavelet splitting method to solve the strongly coupled nonlinear Schrodinger equations.Based on its multi-symplectic formulation,the strongly coupled nonlinear Schr(o|¨)dinger equations can be split into one linear multi-symplectic subsystem and one nonlinear infinite-dimensional Hamiltonian subsystem.For the linear subsystem,the multi-symplectic wavelet collocation method and the symplectic Buler method are employed in spatial and temporal discretization,respectively.For the nonlinear subsystem,the mid-point symplectic scheme is used.Numerical simulations show the effectiveness of the proposed method during long-time numerical calculation.     

Short synthesis of tert-butyl-hydroxylated 3,5-di-tert-butyl-4-hydroxybenzaldehyde: Synthesis of tert-butyl-hydroxylated S-2474

We have developed a very short synthesis of tert-butyl-hydroxylated di-tert-butyl-4-hydroxybenzaldehyde in which the HBr-DMSO system is used as an effective oxidant (overall yield of 45% for the entire four-step process from 2-tert-butyl-p-cresol). We also accomplished the synthesis of a major metabolite of the antiarthritic drug candidate S-2474.     

Pseudo‐Membrane Jackets: Two‐Dimensional Coordination Polymers Achieving Visible Phase Separation in Cell Membrane

Cell membranes contain lateral systems that consist of various lipid compositions and actin cytoskeleton, providing two‐dimensional (2D) platforms for chemical reactions. However, such complex 2D environments have not yet been used as a synthetic platform for artificial 2D nanomaterials. Herein, we demonstrate the direct synthesis of 2D coordination polymers (CPs) at the liquid‐cell interface of the plasma membrane of living cells. The coordination‐driven self‐assembly of networking metal complex lipids produces cyanide‐bridged CP layers with metal ions, enabling “pseudo‐membrane jackets” that produce long‐lived micro‐domains with a size of 1–5 μm. The resultant artificial and visible phase separation systems remain stable even in the absence of actin skeletons in cells. Moreover, we show the cell application of the jackets by demonstrating the enhancement of cellular calcium response to ATP.     

Rapid ‘on-column’ preparation of hydrogen [11C]cyanide from [11C]methyl iodide via [11C]formaldehyde

Hydrogen [¹¹C]cyanide ([¹¹C]HCN) is a versatile ¹¹C-labelling agent for the production of ¹¹C-labelled compounds used for positron emission tomography (PET). However, the traditional method for [¹¹C]HCN production requires a dedicated infrastructure, limiting accessibility to [¹¹C]HCN. Herein, we report a simple and efficient [¹¹C]HCN production method that can be easily implemented in ¹¹C production facilities. The immediate production of [¹¹C]HCN was achieved by passing gaseous [¹¹C]methyl iodide ([¹¹C]CH₃I) through a small two-layered reaction column. The first layer contained an N-oxide and a sulfoxide for conversion of [¹¹C]CH₃I to [¹¹C]formaldehyde ([¹¹C]CH₂O). The [¹¹C]CH₂O produced was subsequently converted to [¹¹C]HCN in a second layer containing hydroxylamine-O-sulfonic acid. The yield of [¹¹C]HCN produced by the current method was comparable to that of [¹¹C]HCN produced by the traditional method. The use of oxymatrine and diphenyl sulfoxide for [¹¹C]CH₂O production prevented deterioration of the molar activity of [¹¹C]HCN. Using this method, compounds labelled with [¹¹C]HCN are now made easily accessible for PET synthesis applications using readily available labware, without the need for the ‘traditional’ dedicated cyanide synthesis infrastructure.

In a reaction column, gaseous [¹¹C]methyl iodide was converted to [¹¹C]formaldehyde in a first layer containing N-oxide and then transformed into hydrogen [¹¹C]cyanide in a second layer containing hydroxylamine-O-sulfonic acid within 2 minutes.     

Uncertainty relations for noise and disturbance in generalized quantum measurements

Heisenberg’s uncertainty relation for measurement noise and disturbance is commonly understood to state that in any measurement the product of the position measurement noise and the momentum disturbance is not less than Planck’s constant divided by 4π. However, it has been shown in many ways that this relation holds only for a restricted class of measuring apparatuses in the most general formulation of measuring processes. Here, Heisenberg’s uncertainty relation is generalized to a relation that holds for all the possible quantum measurements, from which rigorous conditions are obtained for measuring apparatuses to satisfy Heisenberg’s relation. In particular, every apparatus with the noise and the disturbance statistically independent from the measured object is proven to satisfy Heisenberg’s relation. For this purpose, all the possible quantum measurements are characterized by naturally acceptable axioms. Then, a mathematical notion of the distance between probability operator valued measures and observables is introduced and the basic properties are explored. Based on this notion, the measurement noise and disturbance are naturally defined for any quantum measurements in a model independent formulation. Under this formulation, various relations for noise and disturbance are also derived for apparatuses with independent noise, independent disturbance, unbiased noise, and unbiased disturbance as well as noiseless apparatuses and nondisturbing apparatuses. Two models of position measurements are also discussed in the light of the new uncertainty relations to show that Heisenberg’s relation can be violated even by approximately repeatable position measurements.     

Syndiospecific living polymerization of 4-methylstyrene with (trimethyl)pentamethylcyclopentadienyltitanium/tris(pentafluorophenyl)borane/trioctylaluminium catalytic system

The polymerization of 4-methylstyrene with the (trimethyl)pentamethylcyclopentadienyltitanium (Cp*TiMe₃)/tris(pentafluorophenyl)borane (B(C₆F₅)₃)/trioctylaluminium (AlOct₃) catalytic system at –20°C was carried out. The number-average molecular weight (M_n) of the polymers increased linearly with increasing monomer conversion. The propagating chain ends were successfully reacted with tert-butyl isocyanate, and the M_n of the polymer determined by ¹H NMR was in good agreement with the M_n determined by GPC measurement. It is concluded that this catalytic system promoted the syndiospecific living polymerization of 4-methylstyrene.