Transformation Pathway from CdSe Magic‐Size Clusters with Absorption Doublets at 373/393 nm to Clusters at 434/460 nm. Issue 37 (21st June 2021)

• Record Type: Journal Article
• Authors: Zhu, Jinming; Cao, Zhaopeng; Zhu, Yongcheng; Rowell, Nelson; Li, Yan; Wang, Shanling; Zhang, Chunchun; Jiang, Gang; Zhang, Meng; Zeng, Jianrong; Yu, Kui
• Is Part Of: Angewandte Chemie international edition. Volume 60:Issue 37(2021)
• Page Start: 20358
• Page End: 20365
• Publication Date: 2021-06-21
• Subjects: cadmium selenide -- colloidal -- magic-size clusters -- quantum dots -- transformation pathways; Chemistry -- Periodicals; 540
• DOI: 10.1002/anie.202104986
• Languages: English
• ISSNs: 1433-7851

Abstract

Abstract: Divergent interpretations have appeared in the literature regarding the structural nature and evolutionary behavior for photoluminescent CdSe nanospecies with sharp doublets in optical absorption. We report a comprehensive description of the transformation pathway from one CdSe nanospecies displaying an absorption doublet at 373/393 nm to another species with a doublet at 433/460 nm. These two nanospecies are zero‐dimensional (0D) magic‐size clusters (MSCs) with 3D quantum confinement, and are labeled dMSC‐393 and dMSC‐460, respectively. Synchrotron‐based small‐angle X‐ray scattering (SAXS) returns a radius of gyration of 0.92 nm for dMSC‐393 and 1.14 nm for dMSC‐460, and indicates that both types are disc shaped with the exponent of the SAXS form factor equal to 2.1. The MSCs develop from their unique counterpart precursor compounds (PCs), which are labeled PC‐393 and PC‐460, respectively. For the dMSC‐393 to dMSC‐460 transformation, the proposed PC‐enabled pathway is comprised of three key steps, dMSC‐393 to PC‐393 (Step 1), PC‐393 to PC‐460 (Step 2 involving monomer addition), and PC‐460 to dMSC‐460 (Step 3). The present study provides a framework for understanding the PC‐based evolution of MSCs and how PCs enable transformations between MSCs. Abstract : Magic‐size clusters (MSCs) have their own unique precursor compounds (PCs). A PC‐enabled pathway has been proposed for the transformation from photoluminescent (PL) CdSe displaying one absorption doublet at 373/393 (dMSC‐393) to 433/460 (dMSC‐460). This pathway contains three key steps with monomer addition (Step 2) transferring PC‐393 to PC‐460.