Peter Stellberg

Direct Photocatalyzed Hydrogen Atom Transfer (HAT) for Aliphatic C–H Bonds Elaboration

Covalent Organic Frameworks: Design, Synthesis, and Functions

The molecular and solid‐state structure of borazine has been determined at 115 and 160 K by single‐crystal X‐ray crystallography. The molecular structure has C₂ symmetry with small deviations from the expected D_3h symmetry. The mean value of the BN bond length is 1.429(1) A and the interbond angles of the six‐membered ring are 117.1(1)° at the boron atoms and 122.9(1)° at the nitrogen atoms (mean values). Similar to benzene an unambiguous assignment of the molecular symmetry is not possible. — The crystal packing is not comparable to any known phase of benzene, and surprisingly the molecules are not stacked having coplanar rings. Instead, the molecules are found in tilted layers. No significant intermolecular interaction could be detected. The generated difference electron density maps show the typical distribution pattern for polar bonds.

Initiation of cationic polymerization via oxidation of free radicals using pyridinium salts