Neue Strategien zur Totalsynthese von anorganischen Nanostrukturen

Abstract

Die rege Nachfrage nach komplexen Nanomaterialien mit präzise kontrollierten Architekturen und Grenzflächen hat zu einer enormen Entwicklung bei innovativen Syntheseverfahren geführt. Dieser Aufsatz beleuchtet Schlüsselstrategien für die chemische Umwandlung und schrittweise Synthese von anorganischen Mehrkomponenten‐Nanostrukturen, wobei existierende Umwandlungsreaktionen im Nanobereich in Klassen eingeordnet werden, die den bei der Synthese von organischen Molekülen verwendeten entsprechen. Ein Schwerpunkt liegt auf der Übertragung von Konzepten aus der Molekülsynthese auf nanoskalige Systeme: Dazu gehören unter anderem Ortsselektivität, Regio‐ und Chemoselektivität, orthogonale Reaktivität, Kupplungsreaktionen, Strategien zum Schützen und Entschützen sowie Verfahren zur Trennung und Aufreinigung. Das so geschaffene Regelwerk stellt ein neues Modell für die “Totalsynthese” von komplexen anorganischen Nanostrukturen dar, dem die Prinzipien von mehrstufigen Totalsynthesen komplexer organischer Molekülverbindungen und Naturstoffe zugrundeliegen.

Mechanistic Study of the Role of Primary Amines in Precursor Conversions to Semiconductor Nanocrystals at Low Temperature

“…[14] To the best of our knowledge, 2 has never been reported from the synthesis of semiconductor NCs and the mechanism of precursor conversion in Reaction (1) has never been addressed, although primary amines have been widely used as additives in the synthesis of semiconductor NCs. [5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23]37] To verify the assignment of compounds 1 and 2, we performed two reactions of Ph 2 P(Se)Cl and Ph 2 PCl with C 18 H 35 NH 2 , respectively, as presented in Figure S2. Also, Figure S2 indicates that the Se exchange equilibrium between 1 and 2, that is, 1 + HPPh 2 Ð 2 + Se = PPh 2 H, is weighted heavily toward 1, similar to Se = P(C 8 H 17 ) 3 + HPPh 2 Ð P(C 8 H 17 ) 3 + Se=PPh 2 H which is weighted heavily toward SeTOP.…”

Mechanistic Study of the Role of Primary Amines in Precursor Conversions to Semiconductor Nanocrystals at Low Temperature

“…[36] The chemical shift for 1 is similar to that reported for Ph 2 P(Se) À NHC 12 H 25 (57 ppm, J P-Se = 775 Hz), which was monitored from a mixture of Cd(OOCPh) 2 + Se= PPh 2 H + C 12 H 25 NH 2 . [5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23]37] To verify the assignment of compounds 1 and 2, we performed two reactions of Ph 2 P(Se)Cl and Ph 2 PCl with C 18 H 35 NH 2 , respectively, as presented in Figure S2. [5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23]37] To verify the assignment of compounds 1 and 2, we performed two reactions of Ph 2 P(Se)Cl and Ph 2 PCl with C 18 H 35 NH 2 , respectively, as presented in Figure S2.…”

The Formation Mechanism of Binary Semiconductor Nanomaterials: Shared by Single‐Source and Dual‐Source Precursor Approaches

“…The single-source precursors (SSPs) consist of the metallic and nonmetallic elements of the semiconductor constituents in a single molecule. [9][10][11][12][13][14] DSPA uses separated metallic-element and nonmetallic-element precursors, which commonly involve metal carboxylates (M(OOCR) n such as M = Zn, Cd, Pb, Cu, In) and phosphine chalcogenides (such as E = PHR 2 where E = S, Se, Te), [15][16][17][18][19][20][21][22][23][24][25][26][27] respectively. Despite the large number of recipes developed for the various colloidal semiconductor nanocrystals (NCs) in the past 20 years, there is still little understanding of their formation mechanisms.…”

“…[25] DSAPs to E-based semiconductor QDs have become popular with metal carboxylates as cation precursors and diphenylphosphine chalcogenides E = PHPh 2 as anion precursors. [15][16][17][18][19][20][21][22][23][24][25][26][27] Astonishingly, the lack of a common formation mechanism is actually accompanied by the same 31 P NMR identification of RCOO-PPh 2 (R = C 17 H 33 99 ppm (3 in Scheme 1) or C 6 H 5 102 ppm) and Ph 2 P-PPh 2 (À14 ppm, 4) for the various DSPAs to PbSe, [18] CdSe, [19][20][21][22] ZnSe, [23,24] ZnS, [24] and ZnSeS, [24] together with C 17 H 33 COO-P(Se)Ph 2 (77 ppm, 5) for the Se-based NCs. [18,[21][22][23][24] Furthermore, the conversion of Se = PHPh 2 to diphenyldiselenophosphinate derivatives (ÀSeSePPh 2 ) has been documented.…”

“…[1][2][3][4][5][6][7][8][9] Both singlesource and dual-source precursor approaches (SSPA and DSPA) to binary semiconductors have been documented. [9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27] Such materials consist of elements from two groups such as IIB and VIA. The single-source precursors (SSPs) consist of the metallic and nonmetallic elements of the semiconductor constituents in a single molecule.…”