The charge‐transfer complex trans‐STB–TCNQF4

In the crystal structure of the title charge‐transfer complex, namely trans‐stilbene–2,2′‐(2,3,5,6‐tetra­fluoro­benzene‐1,4‐diyl­idene)­propane­di­nitrile (1/1) (trans‐STB–TCNQF₄), C₁₄H₁₂·C₁₂F₄N₄, the planar STB and TCNQF₄ mol­ecules are stacked alternately. The structure is not isostructural with that of STB–TCNQ. No anomaly was found in the displacement parameters of any atoms, while the bond length of the central C=C moiety was shorter than the corresponding bond in ethyl­ene. This suggests that the central C=C moiety of the STB mol­ecule vibrates with a large amplitude, similar to the case in free STB and STB–TCNQ.     

Depolarization field effect on the ferroelectric behavior of polymers

The effect of the depolarization field in crystallites on the ferroelectric behavior of polymers is discussed on the assumption that the crystallite is a prolate ellipsoid with its major axis directed along the electric field. The theory relates the polarization P and the electric field E in the crystallite to the overall values P and E for the polymer. The determination of the P -E hysteresis of a crystallite from the P-E hysteresis is given with examples for poly(vinylidene fluoride) (PVDF) and vinylidene fluoride (VDF)–trifluoroethylene (TrFE) copolymer. The ratio R = J/(P_s ? P), with J the switching current density and P_s the saturation polarization of polymer, is proved to be free from the depolarization field effect and the plot of logR against logarithmic time is shown to have merit for characterization of switching behavior. Examples of the curves are given for PVDF and VDF-TrFE copolymers. The temporal change of local electric field in the unreversed domains in the crystallite in the course of polarization reversal is predicted by the theory and this change is proved to be a significant mechanism of switching acceleration.     

Fusion of the eight vertex SOS model

A higher spin analogue is presented of the eight vertex-SOS correspondence in the sense of Andrews-Baxter-Forrester. The resulting hierarchy of solvable models contain the hard hexagon model and its recent multi-state generalizations.     

Instability in a geometric parabolic equation on convex domain instability on convex domain

We prove that any non-constant smooth static solution to a geometric parabolic system is unstable, provided that the domain is convex. As the important applications, we shall consider the Landau-Lifshitz equation and the heat flow for harmonic map.     

An efficient synthesis of indane-derived bis(oxazoline) and its application to hetero Diels-Alder reactions on polymer support

Indane-derived bis(oxazolines) were synthesized in two steps and 93% overall yield starting from commercially available substrates. This ligand is as effective as tert-butyl bis(oxazoline) in hetero Diels-Alder reaction both in solution and on polymer support.     

State-transition categories

This paper presents the idea to define a category which is related to a state-transition system. To represent our knowledge, we also introduce knowledge functions and fuzzy knowledge functions.     

Penicillin-cephalosporin conversion-XI. Synthesis of 7-(α-substituted phenylacetoamide) cephalosporins by utilization of all the framework elements of penicillin G

A successful synthesis of clinically significant cephalosporins 2a-c with use of all the framework elements of penicillin G is described.