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Hu J, Yang Y, Shen Q, Wang S, Chen X, Luan C, Yu K. Room-Temperature Formation of CdTeSe Magic-Size Clusters from Oleate-Capped CdTe Precursor Compounds via CdSe Monomer Substitution. Inorg Chem 2024; 63:11487-11493. [PMID: 38833379 DOI: 10.1021/acs.inorgchem.4c01775] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/06/2024]
Abstract
We report the first room-temperature synthesis of ternary CdTeSe magic-size clusters (MSCs) that have mainly the surface ligand oleate (OA). The MSCs display sharp optical absorption peaking at ∼399 nm and are thus referred to as MSC-399. They are made from prenucleation-stage samples of binary CdTe and CdSe, which are prepared by two reactions in 1-octadecene (ODE) of cadmium oleate (Cd(OA)2) and tri-n-octylphosphine chalcogenide (ETOP, E = Te and Se) at 25 °C for 120 min and 80 °C for 15 min, respectively. When the two binary samples are mixed at room temperature and dispersed in a mixture of toluene (Tol) and octylamine (OTA), the CdTeSe MSC-399 develops. Also, when the CdSe sample is added to CdTe MSC-371 in a dispersion, the transformation from CdTe MSC-371 to CdTeSe MSC-399 is seen. We propose that the MSCs develop from their precursor compounds (PCs) that are relatively transparent in optical absorption, such as CdTeSe MSC-399 from CdTeSe PC-399 and CdTe MSC-371 from CdTe PC-371. The formation of CdTeSe PC-399 undergoes monomer substitution and not anion exchange, which is the reaction of CdTe PC-371 and the CdSe monomer to produce CdTeSe PC-399 and the CdTe monomer. Our study provides evidence of monomer substitution for the transformation from binary CdTe to ternary CdTeSe PCs.
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Affiliation(s)
- Jie Hu
- Engineering Research Center in Biomaterials, Sichuan University, Chengdu, Sichuan 610065, P. R. China
| | - Yusha Yang
- Engineering Research Center in Biomaterials, Sichuan University, Chengdu, Sichuan 610065, P. R. China
| | - Qiu Shen
- Engineering Research Center in Biomaterials, Sichuan University, Chengdu, Sichuan 610065, P. R. China
| | - Shasha Wang
- Engineering Research Center in Biomaterials, Sichuan University, Chengdu, Sichuan 610065, P. R. China
| | - Xiaoqin Chen
- Engineering Research Center in Biomaterials, Sichuan University, Chengdu, Sichuan 610065, P. R. China
| | - Chaoran Luan
- College of Biomedical Engineering, Sichuan University, Chengdu, Sichuan 610065, P. R. China
| | - Kui Yu
- Engineering Research Center in Biomaterials, Sichuan University, Chengdu, Sichuan 610065, P. R. China
- Institute of Atomic and Molecular Physics, Sichuan University, Chengdu, Sichuan 610065, P. R. China
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Sun X, Wang S, Wang Z, Shen Q, Chen X, Chen Z, Luan C, Yu K. Lower-Temperature Nucleation and Growth of Colloidal CdTe Quantum Dots Enabled by Prenucleation Clusters with Cd-Te Bond Conservation. J Am Chem Soc 2024; 146:15587-15595. [PMID: 38783573 DOI: 10.1021/jacs.4c04593] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/25/2024]
Abstract
The reason why heating is required remains elusive for the traditional synthesis of colloidal semiconductor quantum dots (QDs) of II-VI metal chalcogenide (ME). Using CdTe as a model system, we show that the formation of Cd-Te covalent bonds with individual Cd- and Te-containing compounds can be decoupled from the nucleation and growth of CdTe QDs. Prepared at an elevated temperature, a prenucleation-stage sample contains clusters that are the precursor compound (PC) of magic-size clusters (MSCs); the Cd-Te bond formation occurs at temperatures higher than 120 °C in the reaction. Afterward, the PC-to-QD transformation appears via monomers at lower temperatures in dispersion. Our findings suggest that the number of Cd-Te bonds broken in the PC reactant is similar to that of Cd-Te bonds formed in the QD product. For the traditional synthesis of ME QDs, heating is responsible for the M-E bond formation rather than for nucleation.
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Affiliation(s)
- Xilian Sun
- Engineering Research Center in Biomaterials, Sichuan University, Chengdu, Sichuan 610065, P. R. China
| | - Shasha Wang
- Engineering Research Center in Biomaterials, Sichuan University, Chengdu, Sichuan 610065, P. R. China
| | - Zhe Wang
- Engineering Research Center in Biomaterials, Sichuan University, Chengdu, Sichuan 610065, P. R. China
| | - Qiu Shen
- Engineering Research Center in Biomaterials, Sichuan University, Chengdu, Sichuan 610065, P. R. China
| | - Xiaoqin Chen
- Engineering Research Center in Biomaterials, Sichuan University, Chengdu, Sichuan 610065, P. R. China
| | - Zifei Chen
- ARC Centre of Excellence in Exciton Science, School of Chemistry, The University of Melbourne, Parkville, VIC 3010, Australia
| | - Chaoran Luan
- College of Biomedical Engineering, Sichuan University, Chengdu, Sichuan 610065, P. R. China
| | - Kui Yu
- Engineering Research Center in Biomaterials, Sichuan University, Chengdu, Sichuan 610065, P. R. China
- Institute of Atomic and Molecular Physics, Sichuan University, Chengdu, Sichuan 610065, P. R. China
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Kong X, Deng Y, Zou Y, Ge J, Wang Y. Anion Exchange in Semiconductor Magic-Size Clusters. J Am Chem Soc 2024; 146:5445-5454. [PMID: 38304982 DOI: 10.1021/jacs.3c12853] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2024]
Abstract
Ion exchange is an effective postsynthesis strategy for the design of colloidal nanomaterials with unique structures and properties. In contrast to the rapid development of cation exchange (CE), the study of anion exchange is still in its infancy and requires an in-depth understanding. Magic-size clusters (MSCs) are important reaction intermediates in quantum dot (QD) synthesis, and studying the ion exchange processes can provide valuable insights into the transformations of QDs. Here, we achieved anion exchange in Cd-based MSCs and elucidated the reaction pathways. We demonstrated that the anion exchange was a stepwise intermolecular transition mediated by covalent inorganic complexes (CICs). We proposed that this transition involved three essential steps: the disassembly of CdE1-MSCs into CdE1-CICs (step 1), an anion exchange reaction from CdE1-CICs to CdE2-CICs (step 2), and assembly of CdE2-CICs to CdE2-MSCs (step 3). Step 3 was the rate-determining step and followed first-order reaction kinetics (kobs = 0.01 min-1; from CdSe-MSCs to CdS-MSCs). Further studies revealed that the activity of foreign anions only affected the reaction kinetics without altering the reaction pathway. The present study provides a deeper insight into the anion exchange mechanisms of MSCs and will further shed light on the synthesis of QDs.
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Affiliation(s)
- Xinke Kong
- State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, China
| | - Yalei Deng
- State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, China
| | - Yihao Zou
- State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, China
| | - Junjun Ge
- State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, China
| | - Yuanyuan Wang
- State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, China
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