Synthesen im system {carbonylmetallat/ketenimin/säure}: XXX. Neue ferra- und rhenaazetidine

The metal carbonyl anions [Fe(η-C₅H₅(CO)₂]^? and [Re(CO)₅] undergo regio- and site-specific [2 + 2]-cycloadditions with the ketenimines Ph₂CCNR (R = Me, Ph) to give the (isolable) anionic complexes [L_n$\text{M{C(CPh}{}_2\text{)N(R)C}$(O)}]^? (L_nM = Fe(η-C₅H₅)CO, Re(CO)₄) which have been alkylated and acylated at the exocyclic oxygen atom of the carbonyl function. The result is stable neutral complexes having a metallaazetidine structure which is composed of an α-metallated enamine and an N,O carbene part. IR, ¹H, and ¹³C NMR data are presented.     

Notiz über den α-LiFeO2-Typ: NaPrO2 und NaTbO2

On the α-LiFeO₂ Type of Structure: NaPrO₂ and NaTbO₂ For the first time transparent light-green single crystals of NaPrO₂ [from PrO_1,833: KO_0,50:NaO_0,50 = 1:1.1:1.2 Ni-cylinder, 1000°C, 20 d] and colourless single crystals of hitherto unknown NaTbO₂ [from Na₂TbO₃, Ni-cylinder, 1000°C, 10 d] have been prepared and investigated by X-ray. The tetragonal α-LiFeO₂-type is confirmed. [NaPrO₂: a = 476.19(3), c = 1096.09(11) pm, c/a = 2.30; 107 I₀ (hkl); R = 4.25% R_w = 3.39%, MoKα; NaTbO₂: a = 463.11(3), c = 1037.39(12) pm, c/a = 2.24; 103 I₀ (hkl); R = 3.54%; R_w = 2,81%; MoKα; both space group I4₁/a m d; fourcircle diffractometer Philips PW 1100]. The Madelung Part of Lattice Energy, MAPLE, and the peculiarities of this type of structure are discussed.     

Eine Notiz zum A-Typ der Lanthanoidoxide: Über Pr2O3

The A-type of Lanthanoide Oxides: On Pr₂O₃ . “Reductive” thermal decomposition of K₂PrO₃ [Ni-cylinder, semi-open system, 1000°C, 14 d] leads for the first time to light green single crystals of Pr₂O₃. The structure determination [105 symmetry independent hkl, four circle diffractometer Philips PW 1100; MoKα; R = 6.30%, R_w = 5.01%; space group P3m1; Z = 1; a = 385.77(3), c = 601.20(6) pm] verifies the A-type according to the proposed structure by PAULING .     

Pharmacomodulation of a ligand targeting the HBV capsid hydrophobic pocket

Hepatitis B virus (HBV) is a small enveloped retrotranscribing DNA virus and an important human pathogen. Its capsid-forming core protein (Cp) features a hydrophobic pocket proposed to be central notably in capsid envelopment. Indeed, mutations in and around this pocket can profoundly modulate, and even abolish, secretion of enveloped virions. We have recently shown that Triton X-100, a detergent used during Cp purification, binds to the hydrophobic pocket with micromolar affinity. We here performed pharmacomodulation of pocket binders through systematic modifications of the three distinct chemical moieties composing the Triton X-100 molecule. Using NMR and ITC, we found that the flat aromatic moiety is essential for binding, while the number of atoms of the aliphatic chain modulates binding affinity. The hydrophilic tail, in contrast, is highly tolerant to changes in both length and type. Our data provide essential information for designing a new class of HBV antivirals targeting capsid–envelope interactions.

Small-molecule binding to the Hepatitis B virus core protein hydrophobic pocket, a possible strategy for targeting viral particle assembly.     

Gastrennung mit Hilfe des Zirkulations-Diffusions-Verfahrens Teil I : Hochanreicherung von Gasen in Trennrohren mit natürlicher Zirkulation

Auf der Grundlage des Zirkulations-Diffusions-Prinzips wurden zwei Trennrohre für die Hochanreicherung von Gasen enytwickelt. Als Modellgasmischungen dienten H₂-N₂ Kr-CH₄ und Luft. Neben Wasserdampf wurden Methanol- und Äthaanoldämpfe als Treibmittel benutzt. Gute Trennungen wurden in einem nur 20 cm langen Rohr erzielt, dessen Trennspalt horizontal durch Lamellen in kleine Sektionen und durch ein Drahtdiaphragma vertikal in zwei Ringkammern geteilt wird. Drei Rohre dieses Typs wurden in einer rechteckigen Kaskadenanordnung getestet. Die Theorie des Transportes im Trennrohr sowie die Behandlung des hydrodynamischen Problems werden angegeben. Eine Anwendung des beschriebenen Trennrohres zur Isotopentrennung und zur Gashochanreicherung erscheint aussichtsreich.     

Reactions of P(III)-Halides with Calix[4]Resorcinarenes

Abstract

Reactions of calix[4]resorcinarenes, bearing aliphatic radicals of different length, with P(III)-halides results in the formation of cyclic chlorophosphites and chlorophosphates.     

Spatial coherence properties of monochromatic electromagnetic beams and of laser modes

It is shown that, contrary to common belief, monochromatic light beams are, in general, not spatially completely coherent, i.e., they will, in general, not produce fringes of unit visibility in a Young's double pinhole interference experiment. We cite experiments with laser modes which confirm this result.