Interpolation by type I factors and the flip automorphism

Given two von Neumann algebras $\text{A}$ ?$\text{B}$ we study the relation between the existence of an interpolating type I factor $\text{F}$, namely $\text{A}$ ?$\text{F}$ ?$\text{B}$, the implementability of the flip automorphism of $\text{A}$ ? $\text{A}$ by a unitary in $\text{B}$ ? $\text{B}$, and the statistical independence of $\text{A}$ and $\text{B}$′ ($\text{A}$ and $\text{B}$′ generate a $\text{W}$¹-tensor product). As an application in Q.F.T. we derive in a natural way a structure theorem of Buchholz for the von Neumann algebras of local observables associated to free fields.     

Physico-chemical properties and possible photocatalytic applications of titanate nanotubes synthesized via hydrothermal method

Titanate nanotubes (TNTs) were prepared from TiO₂ P25 via hydrothermal method. The reaction temperature was 130 or 140 °C and the reaction time was 24 or 48 h. The samples were characterized by transmission electron microscopy, X-ray diffraction, thermogravimetry and N₂ adsorption as well as Raman, FTIR-DRS and UV-vis/DR spectroscopy. The obtained samples exhibited similar properties, regardless of the preparation temperature and time. The most notable difference between properties of TNTs prepared under different conditions was observed in case of BET surface area, which was increasing from 386 to 478 m²/g along with increasing the reaction time and temperature. Based on TEM, XRD and TG measurements we have suggested that the structure of TNTs was H₂Ti₂O₄(OH)₂. The TEM and Raman spectroscopy measurements showed that the obtained products contained also low amount of anatase phase. The TNTs exhibited no photoactivity towards degradation of model azo dye Acid Red 18. However, TNTs were successfully applied for photocatalytic generation of CH₄ and H₂ in a solution of acetic acid. The amount of methane produced with application of TNTs synthesized at 140 °C was about 2.5 times higher than that generated with use of TiO₂ P25. To the best of our knowledge this is a first report on the photocatalytic generation of hydrocarbons using TNTs in the current state of the art.     

Stereodivergent syntheses of conduramines and aminocyclitols

[reaction: see text] The diastereomers of 6-amino-cyclohex-3-ene-1,2-diols 1 (4-deoxy-3-conduramines), key building blocks for the syntheses of a large range of natural products, have been enantioselectively prepared. Diastereoselective dihydroxylation of the compounds provided a new family of aminocyclitols 2 (deoxyinosamines). The key reactions of our syntheses are Sharpless catalytic asymmetric epoxidation, diastereoselective addition of vinylmetal reagents to the aldehydes, and ring-closing metathesis (RCM).     

Ultra‐Tough Inverse Artificial Nacre Based on Epoxy‐Graphene by Freeze‐Casting

Epoxy nanocomposites combining high toughness with advantageous functional properties are needed in many fields. However, fabricating high‐performance homogeneous epoxy nanocomposites with traditional methods remains a great challenge. Nacre with outstanding fracture toughness presents an ideal blueprint for the development of future epoxy nanocomposites. Now, high‐performance epoxy‐graphene layered nanocomposites were demonstrated with ultrahigh toughness and temperature‐sensing properties. These nanocomposites are composed of ca. 99 wt % organic epoxy, which is in contrast to the composition of natural nacre (ca. 96 wt % inorganic aragonite). These nanocomposites are named an inverse artificial nacre. The fracture toughness reaches about 4.2 times higher than that of pure epoxy. The electrical resistance is temperature‐sensitive and stable under various humidity conditions. This strategy opens an avenue for fabricating high‐performance epoxy nanocomposites with functional properties.     

Existence of solutions to BVP for linear differential-functional equations of elliptic type

We consider a homogeneous boundary value problem for a linear partial differential-functional equation of elliptic type. We prove the existence of a unique solution to such problem in a Sobolev space.     

Intramolecular azide-alkyne cycloaddition for the fast assembly of structurally diverse, tricyclic 1,2,3-triazoles

The synthesis of novel tricyclic 1,2,3-triazoles starting from cyclic epoxides via the sequential azidolysis, propargylation and 1,3-dipolar cycloaddition is described. Derivatization by N-arylation reaction and the synthesis of enantiomerically pure compounds is also reported. Some of these compounds exhibit significant affinity for the sigma-1 receptor.     

Pushing the Upper Limit of Nucleophilicity Scales by Mesoionic N-Heterocyclic Olefins

A series of mesoionic, 1,2,3-triazole-derived N-heterocyclic olefins (mNHOs), which have an extraordinarily electron-rich exocyclic CC-double bond, was synthesized and spectroscopically characterized, in selected cases by X-ray crystallography. The kinetics of their reactions with arylidene malonates, ArCH=C(CO₂Et)₂, which gave zwitterionic adducts, were investigated photometrically in THF at 20 °C. The resulting second-order rate constants k₂(20 °C) correlate linearly with the reported electrophilicity parameters E of the arylidene malonates (reference electrophiles), thus providing the nucleophile-specific N and s_N parameters of the mNHOs according to the correlation lg k₂(20 °C)=s_N(N+E). With 21<N<32, the mNHOs are much stronger nucleophiles than conventional NHOs. Some mNHOs even excel the reactivity of mono- and diacceptor-substituted carbanions. It is exemplarily shown that the reactivity parameters thus obtained allow to calculate the rate constants for mNHO reactions with further Michael acceptors and predict the scope of reactions with other electrophilic reaction partners including carbon dioxide, which gives zwitterionic mNHO-carboxylates. The nucleophilicity parameters N correlate linearly with a linear combination of the quantum-chemically calculated methyl cation affinities and buried volumes of mNHOs, which offers a valuable tool to tailor the reactivities of strong carbon nucleophiles.