IZCp and PZCp: Redox Non-innocent Cyclopentadienyl Ligands as Electron Reservoirs for Sandwich Complexes.

A long-sustained effort of systematic steric and electronic modification of cyclopentadienyl (Cp) ligands has enabled them to find wide-ranging, valuable applications. Herein, we present two novel Cp ligands: imidazolium- and pyrrolinium-substituted zwitterionic Cps (IZCp and PZCp), whose key utility is redox non-innocence─the ability to participate cooperatively with the metal center in redox reactions. Through the simple metalation of ZCps, the Cr(0) and Mo(0) half-sandwich complexes (IZCp)Cr(CO), (PZCp)Cr(CO), (IZCp)Mo(CO), and (PZCp)Mo(CO), respectively, as well as the Ru(II) sandwich complexes [(IZCp)RuCp]PF and [(PZCp)RuCp]PF were prepared.

Formation of Highly Stable 1,2-Dicarbonyl Organic Radicals from Cyclic (Alkyl)(amino)carbenes.

Two air-stable organic radicals derived from oxalyl chloride and cAAC were synthesized, resulting in the unexpected formation of a known (amino)(carboxy) radical cation ([]BF) and the oxidative formation of a 1,2-dicarbonyl radical cation ([]BF) from a neutral 3-oxetanone compound (). The highly strained and newly discovered was obtained by a single-electron reduction of []BF with a mild reducing agent. This result differs from the generation of NHC-based 1,2-dicarbonyl radicals, indicating the uniqueness of cAAC.

Critical nanofocusing of magnetic dipole moment using a closed plasmonic tip.

Squeezing magnetic dipole (MD) moment into a deep subwavelegnth apex of a tapered tip has not been achieved so far owing to a specific mode volume of a MD resonance which is dependent on an operating wavelength and back reflection of nanofocused waves. We propose a novel strategy for efficient delivery and nanofocusing of optical MD at an apex of a closed resonant plasmonic tip. Due to the ultracompact area (~λ/900) of the nanocavity and resonances assisted by partial mirrors in a plasmonic waveguide, the enhancement factor of magnetic energy density is improved over 5 times.