Quantum nanostructures, compositions thereof, and methods of making and using same
Provided are methods for making quantum nanostructures based on use of a combination of nucleation and growth precursors. The methods can be used to provide quantum nanostructures of a selected size. Also provided are quantum nanostructures, compositions comprising the quantum nanostructures, and uses of the quantum nanostructures. The quantum nanostructures can be used, for example, in imaging applications.
1. A process for preparing quantum nanostructures comprising the steps of:
(a) contacting a first cation source and a second cation source, the first cation source comprising a metal and at least one first ligand and the second cation source comprising the metal and at least one second ligand, and an anion source comprising a metal and at least one ligand, optionally, in a solvent, to form a reaction mixture; and
(b) maintaining the reaction mixture from (a) at a temperature and time sufficient to form the quantum nanostructures,
wherein the first cation source is a nucleation source and the second cation source is a growth source, and at least 90% of the first cation source reacts before more than 10% of the second cation source reacts.
2. The process of claim 1 , further comprising the step of contacting the first cation source, second cation source, and anion source with one or more additional cation sources and/or one or more additional anion sources to form the reaction mixture.
3. The process of claim 1 , further comprising the step of isolating the quantum nanostructures from step (b).
4. The process of claim 1 , wherein the first cation source is a carboxylate salt and the second cation source is a phosphonate salt.
5. The process of claim 4 , wherein the carboxylate salt is a cadmium carboxylate salt and the phosphonate salt is a cadmium phosphonate salt.
6. The process of claim 1 , wherein step (b) is carried out a temperature of from −40° C. to 380° C.
7. The process of claim 6 , wherein step (b) is carried out a temperature of from 200° C. to 250° C.
8. A process for preparing quantum nanostructures comprising the steps of:
(a) contacting a first cation source comprising a metal and at least one first ligand, wherein the first cation source is a nucleation source, and an anion source comprising a metal and at least one ligand, optionally, in a solvent, to form a reaction mixture;
(b) maintaining the reaction mixture from (a) at a temperature and time sufficient to form quantum nanostructure nucleates and such that quantum nanostructure nucleate size stabilizes;
(c) adding a second cation source comprising the metal and at least one second ligand to the reaction mixture from (b), wherein the second source is a growth source; and
(d) maintaining the reaction mixture from (c) at a temperature and time sufficient to form the quantum nanostructures.
9. The process of claim 8 , further comprising the step of contacting the first cation source, second cation source, and anion source with one or more additional cation sources and/or one or more additional anion sources to form the reaction mixture.
10. The process of claim 8 , further comprising the step of isolating the quantum nanostructures from step (d).
11. The process of claim 8 , wherein the first cation source is a carboxylate salt and the second cation source is a phoshonate salt.
12. The process of claim 11 , wherein the carboxylate salt is a cadmium carboxylate salt and the phosphonate salt is a cadmium phosphonate salt.
13. The process of claim 8 , wherein step (b) and/or step (d) is carried out a temperature of from −40° C. to 380° C.
14. The process of claim 13 , wherein step (b) is carried out a temperature of from 200° C. to 250° C.
15. A composition comprising a plurality of quantum nanostructures made by the method of claim 1 comprising quantum nanostructures having a surface terminated by at least 70% cations or anions.