Synthesis of amphiphilic polyelectrolyte block copolymers using “living” radical polymerization. Application as stabilizers in emulsion polymerization

This paper describes the synthesis of amphiphilic block copolymers composed of an ionic poly(styrenesulfonate) first segment and a hydrophobic polystyrene second one, using TEMPO-mediated “living” radical polymerization. These copolymers proved to be efficient stabilizers in the emulsion polymerization of styrene.     

Reactions of a P-chloro-iminophosphane with main group nucleophiles: Syntheses and x-ray crystal structure analyses of two 1,3-diphosphatetraz-3-ene derivatives

The reactions of chloro(2,4,6-tri-tert-butylphenylimino)phosphane with lithium tris(trimethylsilyl)silanide and lithium diphenylketimide furnish products resulting from the incorporation of a second chloroiminophosphane molecule into the primary substitution product and subsequent nucleophilic displacement of the chlorine ligand. The final products have been characterized by X-ray structure analyses, which revealed some remarkable features.     

N,N′‐Bis­[tris­(hydroxy­methyl)­methyl]­ethanedi­amide: six O—H⃛O hydrogen bonds generate only a two‐­dimensional structure

Molecules of the title compound, C₁₀H₂₀N₂O₈, adopt a conformation which is almost centrosymmetric. The mol­ecules are disordered over two sets of sites with an occupancy ratio of 0.94:0.06. In the major form, there are two intramolecular O—H?O hydrogen bonds [O?O 2.756 (4) and 2.765 (4) Å; O—H?O 144 and 146°], in which the two amidic O atoms act as acceptors. In addition, there are four intermolecular O—H?O hydrogen bonds [O?O 2.650 (3)–2.666 (3) Å; O—H?O 158–171°]; these link each mol­ecule to six others in a continuous sheet structure which contains five distinct ring motifs, two of the S(7) type, two of the R(10) type and one of the R(22) type.     

A Krein Space Approach to PT-symmetry

In this note we apply Krein space methods to PT-symmetric problems to obtain conditions for the spectrum to be real and estimates of the number of non-real spectral points. An erratum to this article is available at.     

Alkylation et acylation d'acridanones-9

N-Alkylations and N-acylations of 9-acridanones substituted in position 2 or 3 by nitro and methoxy groups are described. Physical characteristics of the new compounds so obtained are given.