Methods of producing metal sulfides, metal selenides, and metal sulfides/selenides having controlled architectures using kinetic control

1. A method of preparing metal sulfide, metal selenide, metal sulfide/selenide, mixed metal sulfide, mixed metal selenide, or mixed metal sulfide/selenide nanoparticles, the method comprising:

(a) contacting at least two precursor metal salts with a sulfur-containing precursor, a selenium-containing precursor, or a combination or mixture of the sulfur- and selenium-containing precursors, or

(b) contacting a precursor metal salt with a sulfur-containing precursor, a selenium-containing precursor, or a mixture of sulfur- and selenium-containing precursors,

in each case where plural precursor metal salts and/or sulfur-/seleno-containing precursors are employed, the contacting being done simultaneously or sequentially in either order in a solution, each precursor metal salt being capable of reacting with each sulfur- and selenium-containing precursor to form the corresponding metal sulfide and metal selenide, the contacting giving rise to reaction conditions sufficient to control at least one parameter of particle size, particle distribution, and particle composition of the nanoparticles to-a predetermined architecture, the sulfur- or selenium-containing precursor each independently having a structure of Formula (I), Formula (II), or Formula (III), or an isomer, salt, or tautomer thereof,

 wherein

Q 1 is independently —O—, —S—, Se—, —CR 3 R 4 —, —N(R 4 )— or P(R 4 )—;

Q 2 is independently —O—, —S—, Se—, —CR 3 R 4 —, —N(R 3 )— or P(R 3 )—;

Q 3 is an optionally substituted aryl or optionally substituted heteroaryl;

R 1 , R 2 , R 3 , and R 4 are independently at each occurrence H, optionally substituted C 1-24 alkyl, optionally substituted C 3-12 cycloalkyl, optionally substituted C 2-24 alkenyl, optionally substituted C 3-12 cycloalkenyl, optionally substituted aryl, optionally substituted aralkyl, optionally substituted heteroaryl, or optionally substituted heteroaralkyl;

or any two of R 1 , R 2 , R 3 , and R 4 are, within the same structure, linked to form a 5- to 10-membered heterocycle comprising an optionally substituted alkylene or an optionally substituted and/or conjugated alkenylene linkage;

or optionally one or more of R 1 , R 2 , and R 3 is not H;

R 5 is halogen, —CN, —NO 2 , C 1-6 alkoxy, C 1-6 alkyl, C 3-6 cycloalkyl, C 2-6 alkenyl, optionally substituted aryl, optionally substituted aryloxy, optionally substituted aralkyl, optionally substituted heteroaryl, or optionally substituted heteroaralkyl;

q is 0, 1, 2, or 3;

X is S or Se; and

Y is a bond —O—, —S—, or —N(R 3 )—;

with the provisos that, in Formula (I):

when Q 1 R 1 is NH 2 , then Q 2 R 2 is not CH 3 ;

when Q 2 R 2 is NH 2 , then Q 1 R 1 is not CH 3 ; and

when Q 1 is —N(R 4 )— and Q 2 is —N(R 3 )—, then R 1 and R 2 are linked to form a 5- or 6-membered heterocycle comprising an optionally substituted alkylene linkage or a 6-membered heterocycle comprising an optionally substituted alkenylene linkage.

2. The method of claim 1 , comprising contacting two precursor metal salts with the sulfur-containing precursor, the selenium-containing precursor, or a combination of the sulfur- and selenium-containing precursors to form the nanoparticles.

3. The method of claim 1 comprising contacting a precursor metal salt with a combination of a sulfur-containing precursor and a selenium-containing precursor to form the nanoparticles.

4. The method of claim 1 comprising contacting a precursor metal salt with a sulfur-containing precursor, a selenium-containing precursor, or a mixture of sulfur-containing and selenium-containing precursors, each sulfur-containing or selenium-containing precursor independently having a structure of Formula (IA), Formula (II), or Formula (III), or an isomer, salt, or tautomer thereof, in solution under controlled nucleation and growth conditions for the formation of the monodispersed nanoparticles:

wherein

Q 1 is independently —O—, —S—, Se—, —CR 3 R 4 —, —N(R 4 ) or P(R 4 )—;

Q 2 is independently —O—, —S—, Se—, —CR 3 R 4 —, —N(R 3 ) or P(R 3 )—;

Q 3 is optionally substituted aryl or optionally substituted heteroaryl;

R 1 and R 2 are independently at each occurrence optionally substituted C 1-24 alkyl, optionally substituted C 3-12 cycloalkyl, optionally substituted C 2-24 alkenyl, optionally substituted C 3-12 cycloalkenyl, optionally substituted aryl, optionally substituted aralkyl, optionally substituted heteroaryl, or optionally substituted heteroaralkyl;

R 3 and R 4 are independently at each occurrence H, optionally substituted C 1-24 alkyl, optionally substituted C 3-12 cycloalkyl, optionally substituted C 2-24 alkenyl, optionally substituted C 3-12 cycloalkenyl, optionally substituted aryl, optionally substituted aralkyl, optionally substituted heteroaryl, or optionally substituted heteroaralkyl;

or any two of R 1 , R 2 , R 3 , and R 4 are, within the same structure, linked to form an optionally substituted 5- to 10-membered heterocycle comprising an optionally substituted alkylene or an optionally substituted and/or conjugated alkenylene linkage;

or optionally one or more of R 1 , R 2 , and R 3 is not H;

R 5 is halogen, —CN, —NO 2 , C 1-6 alkoxy, C 1-6 alkyl, C 3-6 cycloalkyl, C 2-6 alkenyl, optionally substituted aryl, optionally substituted aryloxy, optionally substituted aralkyl, optionally substituted heteroaryl, or optionally substituted heteroaralkyl;

q is 0, 1, 2, or 3;

X is S or Se; and

Y is a bond —O—, —S— or —N(R 3 )—;

with the provisos that, in Formula (IA):

when Q 1 R 1 is NH 2 , then Q 2 R 2 is not CH 3 ;

when Q 2 R 2 is NH 2 , then Q 1 R 1 is not CH 3 ; and

when Q 1 is —N(R 4 )— and Q 2 is —N(R 3 )—, then R 1 and R 2 are linked to form a 5- or 6-membered heterocycle comprising an optionally substituted alkylene linkage or a 6-membered heterocycle comprising an optionally substituted alkenylene linkage.

5. The method of claim 4 , wherein a mixture of a sulfur- and a selenium-containing precursor is used, the sulfur- and selenium-containing precursors exhibiting pseudo first order kinetics with respect to the metal precursor salt, the pseudo first kinetics of each having an associated pseudo first order rate constant, the ratio of the pseudo first order rate constants being in a range of from 1 to 10, under the reaction conditions employed.

6. The method of claim 5 , wherein the pseudo-first order rate constants, k obs (s −1 ) associated with at least one of the sulfur- or selenium-containing precursors with the metal containing precursor salt is in a range from 1×10 −4 to 1×10 −1 .

7. The method of claim 1 , wherein at least one of the sulfur- or selenium-containing precursors has a structure according to

or an isomer, salt, or tautomer thereof.

8. The method of claim 1 , wherein R 1 and R 2 are, within the same structure, linked to form a 5- to 10-membered heterocycle comprising an optionally substituted alkylene or an optionally substituted and/or conjugated alkenylene linkage.

9. The method of claim 1 , wherein at least one of the sulfur- or selenium-containing precursors has a structure according to:

or an isomer, salt, or tautomer thereof, wherein m is 0, 1, 2, 3, or 4; and

R 5 is halogen, —CN, —NO 2 , C 1-6 alkoxy, C 1-6 alkyl, C 3-6 cycloalkyl, C 2-6 alkenyl, optionally substituted aryl, optionally substituted aryloxy, optionally substituted aralkyl, optionally substituted heteroaryl, or optionally substituted heteroaralkyl.

10. The method of claim 1 , wherein at least one of the sulfur- or selenium-containing precursors has a structure according to:

or an isomer, salt, or tautomer thereof,

wherein n is 0, 1, or 2; and

R 5 is halogen, —CN, —NO 2 , C 1-6 alkoxy, C 1-6 alkyl, C 3-6 cycloalkyl, C 2-6 alkenyl, optionally substituted aryl, optionally substituted aryloxy, optionally substituted aralkyl, optionally substituted heteroaryl, or optionally substituted heteroaralkyl.

11. The method of claim 1 , wherein at least one of the sulfur- or selenium-containing precursors has a structure according to:

or an isomer, salt, or tautomer thereof,

wherein p is 0, 1, 2, 3, 4, 5, or 6; and

R 5 is halogen, —CN, —NO 2 , C 1-6 alkoxy, C 1-6 alkyl, C 3-6 cycloalkyl, C 2-6 alkenyl, optionally substituted aryl, optionally substituted aryloxy, optionally substituted aralkyl, optionally substituted heteroaryl, or optionally substituted heteroaralkyl.

12. The method of claim 1 , wherein at least one of the sulfur- or selenium-containing precursors has a structure according to:

or an isomer, salt, or tautomer thereof,

wherein m is 0, 1, 2, 3, or 4; and

R 5 is halogen, —CN, —NO 2 , C 1-6 alkoxy, C 1-6 alkyl, C 3-6 cycloalkyl, C 2-6 alkenyl, optionally substituted aryl, optionally substituted aryloxy, optionally substituted aralkyl, optionally substituted heteroaryl, or optionally substituted heteroaralkyl.

13. The method of claim 1 , wherein at least one of the sulfur- or selenium-containing precursors has a structure according to:

or an isomer, salt, or tautomer thereof,

wherein q is 0, 1, 2, or 3; and

R 5 is halogen, —CN, —NO 2 , C 1-6 alkoxy, C 1-6 alkyl, C 3-6 cycloalkyl, C 2-6 alkenyl, optionally substituted aryl, optionally substituted aryloxy, optionally substituted aralkyl, optionally substituted heteroaryl, or optionally substituted heteroaralkyl.

14. The method of claim 1 , wherein at least one of the sulfur- or selenium-containing precursors has a structure according to:

15. The method of claim 14 , wherein Q 3 is phenyl or pyridinyl, optionally substituted with 0, 1, 2, 3, or 4 halogen, —CN, —NO 2 , C 1-6 alkoxy, C 1-6 alkyl, C 3-6 cycloalkyl, C 2-6 alkenyl, optionally substituted aryl, optionally substituted aralkyloxy, optionally substituted aralkyl, optionally substituted heteroaryl, or optionally substituted heteroaralkyl.

16. The method of claim 1 , wherein R 3 and R 4 are independently optionally substituted alkyl, optionally substituted aryl, or optionally substituted aralkyl.

17. The method of claim 1 , wherein R 5 in Formula (III) is an optionally substituted alkyl, optionally substituted aryl, or optionally substituted aralkyl.

18. The method of claim 1 or claim 4 , wherein Xis S.

19. The method of claim 1 or claim 4 , wherein X is Se.

20. The method of claim 1 or claim 4 , wherein at least one of the precursor metal salts comprises Cd, Cu, Fe, Ga, Hg, In, Mn, Mo, Ni, Pb, or Zn.

21. The method of claim 1 , wherein at least one of the precursor metal salts comprises a C 2-30 carboxylate, thiocarboxylate, (alkyl)phosphonate, alkylsulfonate, alkylphosphate, alkyl sulfate, alkylphosphonamide, or halide.

22. The method of claim 1 , wherein at least one precursor metal salts comprises Cd, Cu, Fe, Ga, Hg, In, Mn, Mo, Ni, Pb, or Zn.

23. The method of claim 1 , wherein the method comprises contacting a first and second precursor metal salt with a sulfur-containing precursor or a selenium-containing precursor in solution under controlled nucleation and growth conditions.

24. The method of claim 23 , wherein the first and second precursor metal salts are contacted with the sulfur-containing precursor or the selenium-containing precursor at the same time.

25. The method of claim 23 , wherein the first and second precursor metal salts are contacted with the sulfur-containing precursor or the selenium-containing precursor sequentially in either order.

26. The method of claim 1 , wherein the method comprises contacting a precursor metal salt with a sulfur-containing precursor and a selenium-containing precursor in solution under controlled nucleation and growth conditions.

27. The method of claim 26 , wherein the precursor metal salt is contacted with the sulfur-containing precursor and the selenium-containing precursor, at the same time.

28. The method of claim 26 , wherein the precursor metal salt is contacted with the sulfur-containing precursor and the selenium-containing precursor sequentially in either order.

29. The method of claim 26 , wherein the resulting nanoparticles having different amounts of metal sulfide and metal selenide therewithin.

30. The method of claim 1 or claim 4 , resulting in a plurality of monodispersed nanoparticles, each nanoparticle exhibiting a variable composition of metal sulfide/metal selenide throughout its structure.

31. The method of claim 28 , wherein the nanoparticles produced by the method comprise continuously varying graded metal sulfide/metal selenide structures.

32. The method of claim 28 , wherein the nanoparticles produced by the method comprise discontinuously varying core-shell metal sulfide/metal selenide varies discontinuously core-shell structures.

33. The method of claim 1 or claim 4 , wherein the solution is non-aqueous.

34. The method of claim 1 or claim 4 , wherein the solution is or comprises an alkane, alkene, aromatic hydrocarbon, ether or a polyether, or a trialkyl- or triaylphosphine or trialkylphosphine oxide.

35. The method of claim 1 , wherein the nanoparticles prepared by the method are substantially spherical, the nanoparticles having an average mean diameter in a range of from about 1 nm to about 10 nm.

36. The method of claim 1 , wherein the nanoparticles prepared by the method are cylindrical having at least one dimension in a range of from about 1 nm to about 25 nm.

37. The method of claim 1 , wherein nanoparticles prepared by the method exhibit a monodispersity characterized by a standard deviation variance of particle size of less than 5%, relative to the mean particle size of the nanoparticle, as measured by statistical samples of TEM micrographs.

38. The method of claim 1 , wherein the metal sulfide, metal selenide, or mixed metal sulfide/selenide nanoparticles prepared by the method are crystalline.

39. The method of claim 1 , wherein the metal sulfide, metal selenide, metal sulfide/selenide, mixed metal sulfide, mixed metal selenide, or mixed metal sulfide/selenide nanoparticles prepared by the method exhibit the characteristics of quantum dots.

40. The method of claim 1 , wherein the nanoparticles prepared by the method comprise CdS, CdSe, CuS, CuSe, GaS, GaSe, InS, InSe, NiS, NiSe, PbS, PbSe, ZnS, ZnSe or a combination thereof.

41. The method of claim 1 , wherein the size of each nanoparticle prepared by the method is greater than the Exciton Bohr radius of that material.

42. The method of claim 1 , wherein the nanoparticles prepared by the method exhibit:

(a) quantum yields of at least 80%;

(b) less than 5% thermal droop at operating temperatures of 100° C.;

(c) less than 10% flux density saturation at a flux of 100 mW/mm 2 ;

(d) emission wavelengths within 5 nm precision while maintaining a linewidth in a range of 25 nm to 35 nm;

(e) or any combination of two or more of (a)-(d).