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We have tested the ability of N-heterocyclic carbene (NHC)-modified ligands to coordinate and stabilize luminescent CdSe-ZnS core-shell quantum dot (QD) dispersions in hydrophilic media. In particular, we probed the effects of ligand structure and coordination number on the coating affinity to the nanocrystals. We find that such NHC-based ligands rapidly coordinate onto the QDs (requiring ∼5-10 min of reaction time), which reflects the soft Lewis base nature of the NHC groups, with its two electrons sharing capacity. Removal of the hydrophobic cap and promotion of carbene-driven coordination on the nanocrystals have been verified by

The successful growth of colloidal lead halide perovskite quantum dots (PQDs) has generated tremendous interest in the community, due to the unique properties and the promise PQDs offer for use in ...

The successful growth of colloidal lead halide perovskite quantum dots (PQDs) has generated tremendous interest in the community, due to the unique properties and the promise PQDs offer for use in applications involving light-emitting devices and solar cell technology. However, tangible progress in probing their fundamental properties and/or their integration into optoelectronic devices has been hampered by issues of colloidal and photophysical instability. Here, we introduce a promising surface coating strategy relying on a polyzwitterion polymer, where high-affinity binding onto the QDs is driven by multicoordinating electrostatic interactions with the ion-rich surfaces of CsPbBr

A method is described for the resolution of the versatile dearomatization reagent TpW(NO)(PMe3)(η(2)-benzene), in which the 1,3-dimethoxybenzene (DMB) analogue of this complex is synthesized. In turn, the coordinated arene of TpW(NO)(PMe3)(DMB) is protonated with either D or L dibenzoyl tartaric acid (DBTH2) in a butanone/water or 2-pentanone/water solution. Sustained stirring of this mixture results in the selective precipitation of a single form of the diastereomeric salt [TpW(NO)(PMe3)(DMBH)](DBTH). After isolation, the salt can be redissolved, and the DMB ligand can be deprotonated and exchanged for benzene to produce the desired product TpW(NO)(PMe3)(η(2)-benzene) in either its R or S form. The absolute configuration of the tungsten stereocenter in TpW(NO)(PMe3)(η(2)-benzene) can be determined in either case by substituting the naturally occurring terpene (S)-β-pinene for benzene and evaluating the 2D NMR spectrum of the corresponding β-pinene complex.

A new method for the preparation of functionalized piperidines is described in which various dihydropyridine (DHP) complexes of {TpW(NO)(PMe(3))} that are derived from pyridine-borane undergo [4 + 2] cyclocondensation with enones, enals, nitrosobenzene, and several isocyanates to form [2.2.2] bicyclic species. In several cases the diazabicyclooctene products derived from DHP complexes and isocyanates can be further elaborated into novel syn-2,5-disubstituted and 2,3,6-trisubstituted piperidinamides.