Luminescent and Magnetic Properties in Semiconductor Nanocrystals with Radial-Position-Controlled Mn²⁺ Doping

Colloidal nanocrystals (NCs) with radial-position-controlled doping were synthesized to study the effect of the binding symmetry around Mn²⁺ dopant. For the four samples ZnSe:Mn/ZnSe, ZnSe/ZnS­(2 ML):Mn/ZnS­(2 ML), ZnSe/ZnS­(1 ML):Mn/ZnS­(2 ML), and ZnSe:Mn/ZnS­(2 ML), which were in sequence of binding asymmetry around Mn²⁺ dopant, their photoluminescent (PL) peak showed gradual red-shift (579 to 599 nm) and the PL lifetime became monotonously shorter (0.57 to 0.31 ms), while, as indicated in the electronic paramagnetic resonance spectra, the hyperfine splitting constant became larger (67.9 to 68.4 G) and the <i>g</i> factor became smaller (2.0076 to 2.005). The relation between the luminescent and magnetic properties of the Mn-doped NCs was discussed

Ytterbium-Catalyzed Hydroboration of Aldehydes and Ketones

The well-defined heavy rare-earth ytterbium iodide complex <b>1</b> (L₂YbI) has been successfully employed as an efficient catalyst for the hydroboration of a wide range of aldehydes and ketones with pinacolborane (HBpin) at room temperature. The protocol requires low catalyst loadings (0.1–0.5 mol %) and proceeds rapidly (>99% conversion in <10 min). Additionally, catalyst <b>1</b> shows a good functional group tolerance even toward the hydroxyl and amino moieties and displays chemoselective hydroboration of aldehydes over ketones under mild conditions