Pressure‐Induced Conversion of a Paramagnetic FeCo Complex into a Molecular Magnetic Switch with Tuneable Hysteresis

A key challenge in the design of magnetic molecular switches is to obtain bistability at room temperature. Here, we show that application of moderate pressure makes it possible to convert a paramagnetic Fe^III₂Co^II₂ square complex into a molecular switch exhibiting a full dia‐ to paramagnetic transition: Fe^IICo^III ? Fe^IIICo^II. Moreover, the complex follows a rare behavior: the higher the pressure, the broader the magnetic hysteresis. Thus, the application of an adequate pressure allows inducing a magnetic bistability at room temperature with predictable hysteresis width. The structural studies at different pressures suggest that the pressure‐enhanced bistability is due to the strengthening of intermolecular interactions upon pressure increase. An original microscopic Ising‐like model including pressure effects is developed to simulate this unprecedented behavior. Overall, this study shows that FeCo complexes could be very sensitive piezo switches with potential use as sensors.     

Transparent Interconnection of Metro Access and Metro Core Networks Including Protection

We proposed and demonstrated a solution for the transparent interconnection of metro access and metro core networks enabling end-to-end wavelength provisioning including the protection.     

Low density specific heat measurements of para-hydrogen adsorbed on exfoliated graphite

Heat-capacity measurements of para-hydrogen adsorbed on bare graphite foam for coverages below about the $\text{(}\text{3}\text{×}\text{3}\text{) R30°}$ configuration between 0.0126 and 0.0622 Å^?2 were made as a function of temperature in the range of 5 to 25 K using a quasiadiabatic method. From the data a phase diagram is suggested having three distinct regions: a pure $\text{(}\text{3}\text{×}\text{RCD>3}\text{)R30°}$; phase, a coexistence region between $\text{(}\text{3}\text{×}\text{3}\text{)R30°}$ and fluid and a pure fluid region. A tricritical point seems to exist at $\text{T}{}_{\mathrm{TC}}\text{? 12.4 K and}\text{n}{}_{\mathrm{TC}}\text{? 0.039}\text{A}\text{?}{}^{\mathrm{?2}}$. The critical exponent α = 0.37 ± 0.03 was calculated which, within our experimental measurements, is the theoretical 3-state Potts value of $\text{1}\text{3}$. Considering the adatoms behaving as localized Einstein oscillators, for the 0.0636 Å^?2 density, an average Einstein temperature of 54.4 ± 4.9 K was obtained. Our results are compared with data obtained by other authors.     

Stereodifferentiation of some chiral monoterpenes using multidimensional gas chromatography

Summary Heptakis (2,3,6-tri-O-alkyl)--cyclodextrins are used as chiral stationary phases for the resolution of -pinene (1), -pinene (2), limonene (3), -terpineol (4), linalool (5) and the furanoid cis/trans linalool oxides (6) by chirospecific CGC-analysis. The first investigations on the direct chirality evaluation of the monoterpenoid grape and wine flavour compounds 4–6 are reported using enantioselective multidimensional gas chromatography (MDGC) and chiral main columns, coated with peralkylated -cyclodextrins. The fresh grape juice, the corresponding must, the young and the bottle maturated wine of muscat cultivars are investigated.     

Point initial value problem for linear functional differential equations in Banach spaces

Summary The problem of existence and uniqueness of solutions defined on the whole real line and satisfying given initial point data for general abstract linear functional differential equations is considered. The equation is not assumed to be of the delay type. The essence of the method presented here consists in the representation of a solution in the form analogous to the variation of constants formula known for linear ordinary differential equations. It is shown that such an approach can be effectively applied to the problem of existence and uniqueness of solutions satisfying an exponential growth estimate, provided that the deviation of the argument is sufficiently small. The proofs are based on the Banach fixed point principle. Detailed comparison and discussion of the hypotheses ensuring the existence and uniqueness of solutions are presented.     

Reactant concentrations from fluorescence correlation spectroscopy with tailored fluorescent probes. An example of local calibration-free pH measurement

The present account is concerned with the measurement of local reactant concentrations by observing specific fluorescent probes in fluorescence correlation spectroscopy (FCS). The Theoretical Analysis section revisits the photophysical, thermodynamic, and kinetic information that is contained in the corresponding FCS correlation curves. In particular, we examine the conditions under which FCS is revealed as a superior tool to measure concentrations of reactive species. Careful molecular engineering of the specific fluorescent probes that simultaneously integrates photophysical, thermodynamic, and kinetic constraints will be required to benefit most from FCS. We illustrate the FCS titration approach with a series of fluorescent probes that we tailored to measure pH at around 4-6 by FCS after two-photon excitation. We show that an optimal design allows one to access pH without any preliminary calibrations such as the determination of the protonation constant or the photophysical properties of the fluorescent probe.