Turn up the heat! Iron and ruthenium nanoparticles in carbon have been prepared by thermolysis of iron and ruthenium fullerene complexes at 500–900 °C in nitrogen. Differences in their size, formation processes, and catalytic activities have been characterized using TG‐DTA, VT‐TEM, and VT‐XRD analyses.
Paddle wheels and pillars : Layered 3D metal–organic frameworks comprised of paddle‐wheel coordination units are constructed under a variety of conditions to incorporate bridging ligands (as illustrated) that impart desired properties, such as guest‐exchange behavior, luminescence, microporosity, and stability, to the material.
Please release me : The heat generated when metal nanoparticles absorb light results in a significant increase in the temperature of the environment around the particles and is used to selectively break bonds within a molecular system anchored to the nanoparticle surface (see picture). This process represents an advantageous and more universal method to deliver chemicals locally, while avoiding excessive tissue damage.
Three novel large polyazamacrocycles containing two 1,10‐phenanthroline units connected by different polyamine spacers have been synthesised and their protonated forms used as receptors for several aromatic carboxylate anions. The receptors bind to the anions in a 1:1 stoichiometry and exhibit remarkable binding selectivity (see figure). Analysis shows that molecular recognition is governed by π–π stacking interactions and multiple N? H???O?C hydrogen bonds.
Artificial biolumiscence : The use of a supramolecular hydrogel to confine heme proteins and luminol can enhance the quantum yield of chemiluminescence (CL) by about an order of magnitude and give an emission time 4–6 times longer.
Dramatic rate enhancement of reductive elimination of [Ar‐Pd‐C] was observed in the presence of a phosphine/electron‐deficient olefin ligand. Through systematic kinetic investigations of the Negishi coupling of ethyl 2‐iodobenzoate with alkylzinc chlorides (see scheme), the rate constants for reductive elimination of [Ar‐Pd‐C] were determined to be greater than 0.3 s?1, which is about four or five orders of magnitude greater than values reported previously.
Dotting the i's : Stimuli‐responsive optoelectronic devices are formed from the title transistors functionalized with photoactive quantum dots. The p‐type semiconducting tubes show a fast current decrease under UV irradiation and reversibility when the UV irradiation is switched off. In contrast, ambipolar tubes show mirror‐image photoswitching effects when negative and positive gate bias voltages are applied.
