Reversible Transformations at Room Temperature among Three Types of CdTe Magic-Size Clusters

Abstract

We report the first observation of the reversible transformations that occur among three types of CdTe magic-size clusters (MSCs) in dispersion at room temperature and discuss our understanding of the transformation pathway. The reversible transformations were achieved with CdTe prenucleation stage samples, which were prepared with reactions of cadmium oleate [Cd(OA) 2 ] and tri-n-octylphosphine telluride in 1-octadecene and were then dispersed in mixtures of toluene and a primary amine at room temperature. Three types of OA-passivated CdTe MSCs evolved, exhibiting sharp optical absorption singlets peaking at 371, 417, and 448 nm. The MSCs and their immediate precursor compounds (PCs; with no sharp optical absorption) are labeled by the MSC absorption peak wavelengths. The transformation between MSC-371 and MSC-417 has a distinct isosbestic point at ∼385 nm and that between MSC-417 and MSC-448 at ∼430 nm. Our findings suggest that these PC-enabled reversible transformations occur through a process of quasi-isomerization, transforming between PCs and their counterpart MSCs, combined with substitution reactions that cause transformation between the two involved PCs.

Transformation Pathways in Colloidal CdTeSe Magic‐Size Clusters

“…This is due to CdTeP C-371 contained in the CdTeI Ps ample added. [4,[7][8][9] CdTeM SC-371 disappeared afterwards.F rom 60 to 300 min, the change for both MSC-399 and MSC-422 was negligible as compared that shown in Part b.…”

Transformation Pathways in Colloidal CdTeSe Magic‐Size Clusters

“…It is established that colloidal semiconductor compound magic-size clusters (MSCs) have particular precursor compounds (PCs). [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16] Thef ormer (MSC-A) exhibits distinct optical absorption peaking at ac onstant wavelength A expressed in nanometers (nm), while the latter (PC-A) is usually transparent at this wavelength Aa nd to longer wavelengths.T he MSCs and their counterpart PCs are quasi isomers and transform mutually via reversible intramolecular reorganization. Furthermore,t he transformation between types of MSCs has been observed, [1][2][3][4][5][6][7][8][9][10] following ap athway that appears to be PC-enabled comprising three key steps (Scheme S1).…”

“…[1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16] Thef ormer (MSC-A) exhibits distinct optical absorption peaking at ac onstant wavelength A expressed in nanometers (nm), while the latter (PC-A) is usually transparent at this wavelength Aa nd to longer wavelengths.T he MSCs and their counterpart PCs are quasi isomers and transform mutually via reversible intramolecular reorganization. Furthermore,t he transformation between types of MSCs has been observed, [1][2][3][4][5][6][7][8][9][10] following ap athway that appears to be PC-enabled comprising three key steps (Scheme S1). ForaMSC-A to MSC-B transformation, the three steps are MSC-A to PC-A, PC-A to PC-B,and PC-B to MSC-B.However,the reported transformations are limited to those between two binary MSCs, [3][4][5][6][7][8][9][10] or between ab inary MSC and at ernary MSC.…”

“…Furthermore,t he transformation between types of MSCs has been observed, [1][2][3][4][5][6][7][8][9][10] following ap athway that appears to be PC-enabled comprising three key steps (Scheme S1). ForaMSC-A to MSC-B transformation, the three steps are MSC-A to PC-A, PC-A to PC-B,and PC-B to MSC-B.However,the reported transformations are limited to those between two binary MSCs, [3][4][5][6][7][8][9][10] or between ab inary MSC and at ernary MSC. [1,2,5] Before the present study, transformations in ternary MSCs have not been reported.…”

“…[30][31][32] Fors emiconductor binary systems,a nI Ps ample typically contains av ariety of species,i ncluding the corresponding ME PCs, monomers (Mo), and fragments (Fr) (Scheme S2). [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16] After two binary IP samples of CdTea nd CdSe were mixed with each other, ternary CdTeSe MSC-399 was seen to evolve at room temperature when the mixture was incubated or placed in mixtures of toluene (Tol) and octylamine (OTA). [1,2] The formation of the counterpart PC for MSC-399, PC-399, occurred as described by the monomer substitution reaction given in Equation (1): [1] CdTe PC-371 þ CdSe ðMo=FrÞ)…”