Topochemical photocycloaddition in two-dimensional lead-halide coordination polymers with tunable phosphorescence.

Topochemical transformation in which the parent structural motifs are preserved has become a powerful strategy to access new advanced materials. Solid-state topochemical conversion in a single-crystal-to-single-crystal (SCSC) fashion is particularly attractive as it provides design principles with unequivocal structural details. Here, we report a series of two-dimensional (2D) lead-halide coordination polymers with bipyridyl ethylene (bpe) ligands that can undergo quantitative SCSC [2 + 2] photocycloaddition.

Extreme potential photocatalysis enabled by spin-exchange Auger processes in magnetic-doped quantum dots.

Visible-light-absorbing semiconductor nanocrystals have shown great promise as photocatalysts for promoting photoredox chemistry. However, their utilization in organic synthesis remains considerably limited compared to small molecule photosensitizers. Recently, the generation of hot electrons from quantum-confined systems has emerged as a powerful means of photoreduction, yet the efficiencies remain limited under mild conditions.

Triplet Sensitization Photon Upconversion Using Near-Infrared Indirect-Bandgap AgBiS Nanocrystals.

Colloidal semiconductor nanocrystals (NCs) have recently emerged as ideal triplet sensitizers owing to their diverse material composition and spectral tunability. However, the NCs that can efficiently sensitize near-infrared-to-visible photon upconversion remain largely limited to toxic lead-based NCs. Here, we present a new lead-free, near-infrared, indirect-bandgap sensitizer based on AgBiS NCs, enabling near-infrared-to-yellow upconversion with a quantum yield reaching 10.

Two-in-One Ni-Doped CsPbBr Nanocrystals Enabling Acceptorless Photocatalytic Dehydrogenation of Diaryl Hydrazines.

Direct utilization of solar energy by semiconductor nanocrystals for chemical transformations via photocatalysis has recently drawn a great deal of attention. While most photocatalytic reactions are mediated through photoredox events, the ultimate reaction scalability relies on the use of sacrificial agents. The imbalanced population of photogenerated electrons and holes often leads to catalyst degradation through photocorrosion.

Emerging Opportunities of Colloidal Quantum Dots for Photocatalytic Organic Transformations.

Colloidal quantum dots (QDs) have emerged as a versatile photocatalyst for a wide range of photocatalytic transformations owing to its high absorption coefficient, large surface-to-volume ratio, high stability, and efficient charge and energy transfer dynamics. The past decades have witnessed a rapid development of QDs for artificial photocatalysis. In this review, the unique characteristics of QDs are focused on, including quantum size effect, compositional and structural diversity, tunable surface chemistry, and photophysics, that can be utilized for photocatalytic transformations.

Synthesis of Metastable Silver-Lanthanide Double Perovskite Nanocrystals with White-Light Emission.

Four silver-lanthanide double perovskite nanocrystals, namely, CsAgSmCl, CsAgEuCl, CsAgGdCl, and CsAgErCl, were synthesized for the first time. These four double perovskites have yet to be reported in any form and are found to be metastable in the bulk phase. By using the colloidal hot-injection synthesis method, the metastable double perovskite phase can be arrested kinetically.