Two poly(ethy1ene oxide) stars linked by a long polystyrene chain represent a novel amphiphilic architecture (dumbbell), which is available by anionic grafting of ethylene oxide from a hydroxylated polybutadiene-block-polystyrene-block-polybutadiene triblock copolymer. The short butadiene end-blocks (DP, = 36) of a BSB triblock copolymer with a long styrene middle block (DP, = 650) was first modificd by hydroboration and oxidation. A multifunctional alkoxide initiator is thus prepared by titration of the hydroxyl groups of the "polybutadiene" endblock with cumylpotassium. Gelation and precipitation of the polyfunctional initiator in THF could be avoided by complexing the cation (K') with a suitable cryptand (Kryptofix[2.2.2ITM). This multifunctional macroinitiator was used to polymerize ethylene oxide. Dumbbell-shaped molecules with various number and length of PEO branches were synthesized. Some first results about their solution properties are presented and discussed based on viscosity and light scattering measurements.

The homoleptic pyrazolate complexes [CeIII4(Me2pz)12] and [CeIV(Me2pz)4]2 quantitatively insert CO2 to give [CeIII4(Me2pz⋅CO2)12] and [CeIV(Me2pz⋅CO2)4], respectively (Me2pz=3,5‐dimethylpyrazolato). This process is reversible for both complexes, as observed by in situ IR and NMR spectroscopy in solution and by TGA in the solid state. By adjusting the molar ratio, one molecule of CO2 per [CeIV(Me2pz)4] complex could be inserted to give trimetallic [Ce3(Me2pz)9(Me2pz⋅CO2)3(thf)]. Both the cerous and ceric insertion products catalyze the formation of cyclic carbonates from epoxides and CO2 under mild conditions. In the absence of epoxide, the ceric catalyst is prone to reduction by the co‐catalyst tetra‐n‐butylammonium bromide (TBAB).

Not just hilariously effective baits! Rare-earth-metal compounds selectively react with aldehydes, ketones and carbon dioxide to generate isolable compounds as crucial intermediates in organic synthesis and homogenous catalysis.

Homoleptic cerous precursors Ce[N(SiMe3)2]3, [Ce{OSi(OtBu)3}3]2 and [Ce{OSiiPr3}3]2 were employed as thermally robust, weakly nucleaophilic compounds to assess their reactivity toward 1,4-quinones in non-aqueous solution. The strongly oxidizing quinones 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ)...