WO2018125523A1 - Janus heterodimers, their preparation and their use - Google Patents

Abstract

The present disclosure relates to a hybrid nanoparticle comprising a heterodimer represented by M₁M₂, wherein M₁ and M₂ each, independently, comprise or consist of a metal or metal oxide; at least one dendron attached to M₁ and/or at least one dendron attached to M₂. The present disclosure also relates to methods for preparing the hybrid nanoparticles described herein and films containing said hybrid nanoparticles.

Description

JANUS HETERODIMERS, THEIR PREPARATION AND THEIR USE

Cross Reference to Related Applications This application claims the priority of U.S. Provisional Application No. 62/440,578 filed December 30, 2016, which is hereby incorporated by reference in its entirety.

Field of the Invention The present disclosure relates to a hybrid nanoparticle comprising a heterodimer represented by MiM₂, wherein Mi and M₂ each, independently, comprise or consist of a metal or metal oxide; at least one dendron attached to Mi and/or at least one dendron attached to M₂. The present disclosure also relates to methods for preparing the hybrid nanoparticles described herein and films containing said hybrid nanoparticles.

Background

Inorganic nanoparticles (NPs) are the main building blocks of nanotechnology and are under extensive research as they provide distinctive physical properties which originate from their specific size, shape, composition and surface chemistry that differ from those of bulk materials. NPs find applications in broad areas such as electronic devices, bio imaging, data storage, optical and chemical sensors and catalysis. The successful implementation of NPs into devices require two key aspects to be addressed: (i) well controlled synthesis of nano-sized building blocks and (ii) their self-assembly into functional architectures.

Control over directional interactions is possible by the formation of amphiphilic systems where two types of ligands (hydrophobic and hydrophilic) are attached on different sides of particles to create a Janus particle, alluding to the two-faced

Roman god, Janus. The self-assembly of Janus particles can produce a series of more complex and delicate structures than isotropic building blocks and give deep understanding about anisotropic interactions and self-assembly mechanisms.

Known methods for forming Janus particles are generally applied to micron or submicron sized particles. However, the preparation of nanometer-sized Janus particles is much rarer as the asymmetric modification, visualization, characterization and unambiguous verification of their Janus nature is significantly more challenging at the nanoscale.

Thus, there is an unresolved need for the development of nano-sized Janus particles having desirable self-assembly properties that can be accessed in an efficient, scalable and yet simple manner. Herein, hybrid nanoparticles formed from

heterodimers and surface binding dendritic ligands, their preparation, and their use, are described.

Summary of the Invention

In a first aspect, the present disclosure relates to a hybrid nanoparticle comprising:

a heterodimer represented by M M₂,

wherein M-i and M₂ each, independently, comprise or consist of a metal or metal oxide;

at least one dendron attached to Mi and/or

at least one dendron attached to M₂.

In a second aspect, the present disclosure relates to a compound having formula (I) or (II):

wherein L-ι and L₂ are each, independently, hydrocarbylene, typically C₁-C₂₀ alkylene;

Zi and Z₂ are each, independently, 0 or NH;

Ai and A₂ are each, independently, H, hydrocarbyl, or

1

wherein Ri is hydrocarbyl, typically Ci_-4 alkyl, more typically methyl; Di and D₂ are each, same or different, a divalent moiety, typically methylene;

n is an integer from 1 to 6;

R₂ and R₃ are each, independently, H, hydrocarbyl, -(C=0)-

hydrocarbyl, or

wherein R₄ is hydrocarbyl, typically Ci_-4 alkyl;

m is an integer from 1 to 4, typically m is 2;

p is an integer from 1 to 6, typically p is 3;

is -COOR5, -POsReRy, -CN,

or

wherein

R₅, R₆, and R₇, are each, independently, H or hydrocarbyl; Rs, Rg, R-io, Rii , Ri2, Ri3, Ri4, R-I 5, Ri6, Ri7, and R-is are each, independently, H, OH, CN, halogen, COOH, or hydrocarbyl; and wherein L-i , L₂, R2, and R₃ are each optionally interrupted by one or more divalent moieties.

In a third aspect, the present disclosure relates to a method for making the hybrid nanoparticles described herein, the method comprising:

(a) contacting a heterodimer represented by MiM₂,

wherein M-i and M₂ each, independently, comprise or consist of a metal or metal oxide, with a first compound that selectively attaches to M-i or M₂; and

(b) recovering the hybrid nanoparticles formed in step (a).

In a fourth aspect, the present disclosure relates to a film comprising a plurality of hybrid nanoparticles described herein.

Brief Description of the Figures

FIG. 1 schematically shows (a) the general structure of a dendrimer, (b) the spatial arrangement of four different units which make up a typical dendrimer, and (c) segments of dendrons in a typical dendrimer.

FIG. 2 shows a TEM image of platinum nanocube seeds used to form the hybrid nanoparticles described herein. FIG. 3 shows (a) TEM image of as-synthesized iron oxide-Pt heterodimers. Inset shows higher magnification area of the same sample; (b) TEM image of

heterodimers after functionalization of the iron-oxide part with dendron 7. Inset shows higher magnification area of the same sample; (c) TEM image of a monolayer of hybrid nanoparticles (after functionalizing Pt part with dendron 13); and (d) TEM image of a bilayer of inventive hybrid nanoparticles. Scale bars in FIG. 3a, 3b, and 3d are each 400 nm and in FIG. 3c is 100 nm. Scale bars in insets of 3a and 3b are each 100 nm. FIG. 4 shows a TEM image of some inventive hybrid nanoparticles (after functionalizing iron oxide part with compound 7 and Pt part with compound 9). FIG. 5 shows a TEM image of some hybrid nanoparticles (after functionalizing iron oxide part with compound 7 and Pt part with compound 11 ).

FIG. 6 shows a SEM image of a self-assembled monolayer formed from hybrid nanoparticles described herein.

Detailed Description

As used herein, the terms "a", "an", or "the" means "one or more" or "at least one" unless otherwise stated.

As used herein, the term "comprises" includes "consists essentially of" and "consists of." The term "comprising" includes "consisting essentially of" and "consisting of."

Throughout the present disclosure, various publications may be cited and/or may be incorporated by reference. Should the meaning of any language in such publications incorporated by reference conflict with the meaning of the language of the present disclosure, the meaning of the language of the present disclosure shall take precedence, unless otherwise indicated. As used herein, the terminology "(Cx-Cy)" in reference to an organic group, wherein x and y are each integers, means that the group may contain from x carbon atoms to y carbon atoms per group.

As used herein, the term "hydrocarbyl" means a monovalent radical formed by removing one hydrogen atom from a hydrocarbon, typically a (Ci-C₄₀) hydrocarbon. Hydrocarbylene groups may be straight, branched or cyclic, and may be saturated or unsaturated. Examples of hydrocarbyl groups include, but are not limited to, alkyl, alkenyl, alkynyl, and aryl.

Analogously, the term "hydrocarbyiene" means a divalent radical formed by removing two hydrogen atoms from a hydrocarbon, typically a (Ci-C₄₀) hydrocarbon. Hydrocarbyiene groups may be straight, branched or cyclic, and may be saturated or unsaturated. Examples of hydrocarbyiene groups include, but are not limited to, alkylene, alkenylene, alkynylene, and arylene, such as 1 ,2-benzene; 1 ,3-benzene; 1 ,4-benzene; and 2,6-naphthalene.

As used herein, the term "alkyl" means a monovalent straight or branched saturated hydrocarbon radical, more typically, a monovalent straight or branched saturated (Ci-C₄₀) hydrocarbon radical, such as, for example, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, hexyl, 2-ethylhexyl, octyl, hexadecyl, octadecyl, eicosyl, behenyl, tricontyl, and tetracontyl.

As used herein, the term "alkenyl" means a monovalent straight or branched unsaturated hydrocarbon radical, more typically, a monovalent straight or branched unsaturated (C2-C₄o) hydrocarbon radical, having one or more double bonds.

Double bonds may have E or Z configuration, based on lUPAC designation, and may be isolated or conjugated. Examples of alkenyl groups include, but are not limited to, ethenyl, n-butenyl, linoleyl, and oleyl.

As used herein, the term "alkynyl" means a monovalent straight or branched unsaturated hydrocarbon radical, more typically, a monovalent straight or branched unsaturated (C₂-C₄₀) hydrocarbon radical, having one or more triple bonds. Triple bonds may be isolated or conjugated. Examples of alkynyl groups include, but are not limited to, ethynyl, n-propynyl, and n-butynyl. As used herein, the term "alkylene" means a divalent straight or branched saturated hydrocarbon radical, more typically, a divalent straight or branched saturated (Ci- C₄₀) hydrocarbon radical, such as, for example, methylene, ethylene, n-propylene, n- butylene, hexylene, 2-ethylhexylene, octylene, hexadecylene, and octadecylene.

Any substituent described herein may optionally be substituted at one or more carbon atoms with one or more, same or different, substituents described herein. For instance, an alkylene group may be further substituted with an alkyl group. Any substituent described herein may optionally be substituted at one or more carbon atoms with one or more substituents selected from the group consisting of halogen, such as, for example, F, CI, Br, and I; nitro (N0₂), cyano (CN), amino (NH₂), carboxylic and benzoic acids (C0₂H, PhC0₂H) and hydroxy (OH).

The present disclosure relates to a hybrid nanoparticle comprising:

a heterodimer represented by M M₂,

wherein M-i and M₂ each, independently, comprise or consist of a metal or metal oxide;

at least one dendron attached to Mi and/or

at least one dendron attached to M₂.

As used herein, the term "heterodimer" refers to a particle having two components Mi and M₂. The two components Mi and M₂ are typically distinct from each other. M-i and M₂ of the heterodimer may each comprise a metal or metal oxide. Suitable metals include, for example, main group metals such as, e.g., lead, tin, bismuth, antimony and indium, and transition metals, e.g., a transition metal selected from the group consisting of gold, silver, copper, nickel, cobalt, palladium, platinum, iridium, osmium, rhodium, ruthenium, rhenium, vanadium, chromium, manganese, niobium, molybdenum, tungsten, tantalum, titanium, zirconium, zinc, mercury, yttrium, iron and cadmium. Suitable metal oxides are any oxides of the metals recited herein. With respect to metals having multiple oxidation states, such as, for example, transition metals, it would be understood by a person of ordinary skill in the art that the corresponding metal oxide includes multiple combinations of oxygen with the metal. For example, iron oxide would include compounds of the formula Fe₃O₄ and Fe₂O₃. In an embodiment, M-i comprises or consists of a metal, typically a transition metal, more typically a transition metal selected from the group consisting of gold, silver, and platinum, still more typically platinum.

In an embodiment, M₂ comprises or consists of a metal oxide, typically a transition metal oxide, more typically a transition metal oxide selected from the group consisting of iron oxide, manganese oxide, and titanium oxide, still more typically iron oxide having the formula Fe₃0₄.

Dendritic polymers include generally any of the known dendritic architectures including dendrimers, dendrons, typically regular dendrons, controlled

hyperbranched polymers, dendrigrafts, and random hyperbranched polymers.

Dendritic polymers are polymers with densely branched structures having a large number of reactive groups. A dendritic polymer includes several layers, or generations, of repeating units which all contain one or more branch points.

Dendritic polymers, including dendrimers and hyperbranched polymers, are prepared by condensation reactions of monomeric units having at least two reactive groups. In general, dendrimers comprise a plurality of dendrons that emanate from a common core, which can be a single atom or a group of atoms. Each dendron generally consists of terminal surface groups, interior branch junctures having branching functionalities greater than or equal to two, and divalent connectors that covalently connect neighboring branching junctures. Dendrons and dendrimers can be prepared by convergent or divergent synthesis. Divergent synthesis of dendrons and dendrimers involves a molecular growth process which occurs through a consecutive series of geometrically progressive step-wise additions of branches upon branches in a radially outward molecular direction to produce an ordered arrangement of layered branched shells.

Convergent synthesis of dendrimers and dendrons involves a growth process which begins from what will become the surface of the dendron or dendrimer and progresses radially in a molecular direction toward a focal point or core. The dendritic polymers may be ideal or non-ideal, i.e., imperfect or defective.

Imperfections are normally a consequence of either incomplete chemical reactions, or unavoidable competing side reactions. The general structure of dendrimers is schematically shown in FIG. 1 a. The center of the structure is the core 1 , which core may be non-metallic or metallic. In the example of FIG. 1 a the core has three arms, or dendrons. However, in general the core can have any number of dendrons. Herein, the term "dendron" refers to a dendritic arm that is attached to a core.

Each dendron of the core begins with a first "shell" of repeating units 2 connected, each of which branches into at least two new branches. When going from the core to the outside of the structure, the example shown in FIG. 1 a comprises altogether three shells of repeating units. Therefore, the dendrimer structure shown is called a generation-3 (G3) dendrimer. According to the present disclosure, dendrimers and dendrons of various generations can be used. Typically, generations 1 -6, still more typically, generations 1 -4, are used. In the example shown in FIG. 1 a, since each repeating unit shown branches into two limbs, each shell of repeating units is doubling the total number of branches. Therefore the whole number of branches at the surface of the structure is 24 (3 x 2ⁿ, wherein n is the generation). In general, it is also possible to have dendrimer structures in which each repeating unit branches into more than two limbs. When going from the inside to the outside of the structure shown in FIG. 1 a, the last shell of repeating units is optionally followed by a shell of spacer units 3. As seen in the figure, to each of the 24 branches a spacer unit is connected. These optional spacer units have the function to bind the capping groups 4 to the outer shell of repeating units. Typically, the capping groups 4 are connected directly to the last shell of the repeating units. FIG. 1 b schematically shows the spatial arrangement of the four different units, which form a typical dendrimer structure. In center is the core 1 , which is surrounded by at least one shell of repeating units 2. The shells of repeating units are followed by a shell of optional spacer units 3, which at the outside of the dendrimer is surrounded by an outer shell of capping groups 4. The shells of repeating units may be formed by chemically and structurally identical units or by chemically and/or structurally different units. The repeating units may be different from shell to shell and/or may differ within one shell. In addition, the dendrimer structure may comprise chemically and/or structurally identical or different capping groups and optional spacer units. The repeating units may be attached to the core through covalent bonds such as carbon-carbon bonds or functional bonds, for example, ester bonds, amide bonds, and thioether bonds.

According to the number of dendrons of the core 1 , the dendrimer structure may be divided into dendrons 5 as shown in FIG. 1 c. If the dendrimer is synthesized by a convergent approach, the chemical composition and/or the structural features of the dendrons (repeating units, the optional spacer units, and/or the capping groups) may differ from dendron to dendron.

The outer surface shell of dendritic polymers, including dendrimers and dendrons, may contain either chemically reactive or passive functional capping groups.

Chemically reactive capping groups can be used for further extension of dendritic growth or for modification of dendritic molecular surfaces. The chemically passive capping groups may be used to physically modify dendritic surfaces, such as to adjust the ratio of hydrophobic, or lipophilic, to hydrophilic, or lipophobic, terminals, and/or to improve the solubility of the dendritic polymer, dendrimer, or dendron, for a particular solvent.

In an embodiment, the at least one dendron attached to M-i and/or the at least one dendron attached to M₂ is derived from a compound having formula (I) or formula (II):

(li)

wherein

L-i and L₂ are each, independently, hydrocarbylene, typically C-₁-C₂₀ alkylene;

Zi and Z₂ are each, independently, 0 or NH;

Ai and A₂ are each, independently, H, hydrocarbyl, or

wherein Ri is hydrocarbyl, typically Ci_-4 alkyl, more typically methyl; Di and D₂ are each, same or different, a divalent moiety, typically methylene;

n is an integer from 1 to 6;

R₂ and R₃ are each, independently, H, hydrocarbyl, -(C=0)-

hydrocarbyl, or

wherein R₄ is hydrocarbyl, typically Ci_-4 alkyl;

m is an integer from 1 to 4, typically m is 2;

p is an integer from 1 to 6, typically p is 3; , or

wherein

R₅, R₆, and R₇, are each, independently, H or hydrocarbyl; Re, R9, R10, R11 , R12, Ri3, Ri4, Ri5, R16, Ri7, and R-is are each, independently, H, OH, CN, halogen, COOH, or hydrocarbyl; and wherein L₂, R2, and R₃ are each optionally interrupted by one or more divalent moieties.

In an embodiment, a dendron derived from the compound having formula (I) is attached to M₂.

In an embodiment, the dendron attached to M₂ is derived from the compound having formula (I), wherein

l_i is hydrocarbylene;

wherein Ri is hydrocarbyl;

Di and D₂ are each, same or different, a divalent moiety; n is an integer from 1 to 6;

R₂ and R₃ are each, independently, hydrocarbyl or -(C=O)-hydrocarbyl; Xi is -PO₃H₂; and wherein L-ι , R₂, and R₃ are each optionally interrupted by one or more divalent moieties.

In an embodiment, a dendron derived from the compound having formula (II) ^' attached to I ^ .

In an embodiment, the dendron attached to Mi is derived from the compound having formula (II), wherein

l_2 is hydrocarbylene;

wherein R-i is hydrocarbyl;

D-i and D₂ are each, same or different, a divalent moiety; n is an integer from 1 to 6;

R₂ and R₃ are each H; and

wherein L₂ is optionally interrupted by one or more divalent moieties.

As used herein, the phrase "interrupted by one or more divalent moieties" when used in relation to a substituent means a modification to the substituent in which one or more divalent moieties are inserted into one or more covalent bonds between atoms. The interruption may be in a carbon-carbon bond, a carbon-hydrogen bond, a carbon-heteroatom bond, a hydrogen-heteroatom bond, or heteroatom-heteroatom bond. The interruption may be at any position in the substituent modified, even at the point of attachment to another structure.

The one or more divalent moieties may be selected from the group consisting of the following: R, a o

_ N=N-

As used herein, the asterisks indicate a point of connection.

Each occurrence of R_a-R_k, are each, independently H, halogen, typically F, or alkyi. When any of R_a-R_k is alkyi, the alkyi group may optionally be interrupted by one or more divalent moieties defined herein.

The generation n is, typically, 1 to 6, more typically, 1 to 4, still more typically, 1 to 3. In an embodiment, n is 2. In an embodiment, Xi is -PO3R6R7.

In an embodiment, R-i is methyl.

In an embodiment, Di and D₂ are each methylene.

In an embodiment, L-i and L₂ are each d₂-alkylene. In another embodiment, L-i and

N

V

l_₂ are each Ci₂-alkylene interrupted by

The present disclosure relates to a compound having formula (I) or (II): X 1 L 1 A 1

I)

wherein

l_i and L₂ are each, independently, hydrocarbylene, typically C1-C20 alkylene;

Z-i and Z₂ are each, independently, 0 or NH;

A and A₂ are each, independently, H, hydrocarbyl, or

wherein R-i is hydrocarbyl, typically Ci_-4 alkyl, more typically methyl; D-i and D₂ are each, same or different, a divalent moiety, typically methylene;

n is an integer from 1 to 6;

R₂ and R₃ are each, independently, H, hydrocarbyl, -(C=0)-

hydrocarbyl, or

wherein R₄ is hydrocarbyl, typically Ci_-4 alkyl;

m is an integer from 1 to 4, typically m is 2;

p is an integer from 1 to 6, typically p is 3; -COOR5, -POsReRy, -CN,

wherein

R₅, R₆, and R₇, are each, independently, H or hydrocarbyl;

Re, R9, R10, R-11 , R12, Ri3, Ri4, Ri5, R16, Ri7, and R-is are each, independently, H, OH, CN, halogen, COOH, or hydrocarbyl; and wherein L-i , L₂, R2, and R₃ are each optionally interrupted by one or more divalent moieties. mbodiment the compound is a compound having formula (II):

wherein

l_2 is hydrocarbylene, typically C1-C20 alkylene;

Z₂ is O or NH;

A₂ is H, hydrocarbyl, or

wherein Ri is hydrocarbyl, typically Ci_-4 alkyl, more typically methyl; Di and D₂ are each, same or different, a divalent moiety, typically methylene;

n is an integer from 1 to 6; R₂ and R₃ are each H; and

wherein L₂, R2, and R₃ are each optionally interrupted by one or more divalent moieties. The compounds complying with formula (I) or (II) may be made according to methods known to those of ordinary skill in the art.

For example, a suitable method for synthesizing a compound having formula (I) comprises:

reacting a compound represented by the structure of formula

wherein X is -COOR5, -P

0₃R₆R7, -CN, i 1 ί

wherein

R₅, R₆, and R₇, are each, independently, H or hydrocarbyl; and Re, R9, R-io, R11 , R12, Ri3, R-I4, Ri5, R16, Ri7, and R-is are each, independently, H, OH, CN, halogen, COOH, or hydrocarbyl; with a compound represented by the structure of formula (IV):

G₂ A₁

^{2 1} (IV)

wherein

A-i is H, hydrocarbyl, or

wherein Ri is hydrocarbyl, typically Ci_-4 alkyl, more typically methyl; Di and D₂ are each, same or different, a divalent moiety, typically methylene;

n is an integer from 1 to 6;

R₂ and R₃ are each, independently, H, hydrocarbyl, -(C=0)-

hydrocarbyl, or

wherein R₄ is hydrocarbyl, typically Ci_-4 alkyl;

m is an integer from 1 to 4, typically m is 2;

p is an integer from 1 to 6, typically p is 3; and

each occurrence of d is a substituent comprising a reactive group capable of reacting with the reactive group in G₂, and

G₂ is a substituent comprising a reactive group capable of reacting with the reactive group in G-i .

The generation n is, typically, 1 to 6, more typically, 1 to 4, still more typically, 1 to 3. In an embodiment, n is 2.

In an embodiment, X-i is -P0₃R₆R7.

In an embodiment, Ri is methyl.

In an embodiment, D-i and D₂ are each methylene. Gi is a substituent comprising a reactive group capable of reacting with the reactive group in G₂, and G₂ is a substituent comprising a reactive group capable of reacting with the reactive group in G-i. Typically, Gi is a d-C-15-alkyl group, optionally interrupted by one or more divalent moieties defined herein, comprising a reactive group capable of reacting with the reactive group in G2.

In an embodiment, G1 comprises a reactive group selected from the group consisting of -X, -NH₂, -N₃, -(C=0)X, -Ph(C=0)X, -SH, -CH=CH₂, -C≡CH^■ wherein X is a leaving group.

In an embodiment, Gi is a C-i-C-15-alkyl group comprising a -N₃ group. Typically, G₂ is a C-i-C-15-alkyl group, optionally interrupted by one or more divalent moieties defined herein, comprising a reactive group capable of reacting with the reactive group in G-i.

In an embodiment, G₂ comprises a reactive group selected from the group consisting of -(C=0)X, -CH=CH₂, -C≡CH __{N H2} __Ns -p_n(C=0)X, -SH, -X, -NCO, -NCS;

wherein X is a leaving group.

Leaving groups are known to those of ordinary-skill in the art. Suitable leaving groups include, but are not limited to, halides, such as, fluoride, chloride, bromide, and iodide; alkyl and aryl sulfonates, such as methanesulfonate (mesylate) and p- toluenesulfonate (tosylate); and hydroxide.

In an embodiment, G₂ is a C-i-C-15-alkyl group comprising a— C≡CH group, and is interrupted by a -0- group.

According to the present disclosure, it is understood that the reactive groups on Gi and G₂ may be reversed. In another example, a suitable method for synthesizing a compound having formula (II) comprises:

reacting a compound represented by the structure of formula (V):

with a compound represented by the structure of formula (VI):

wherein

A₂ is H, hydrocarbyl, or

wherein R-i is hydrocarbyl, typically Ci_-4 alkyl, more typically methyl; D-i and D₂ are each, same or different, a divalent moiety, typically methylene;

n is an integer from 1 to 6;

R₂ and R₃ are each, independently, H, hydrocarbyl, -(C=0)-

hydrocarbyl, or

wherein R₄ is hydrocarbyl, typically Ci_-4 alkyl;

m is an integer from 1 to 4, typically m is 2;

p is an integer from 1 to 6, typically p is 3; and each occurrence of d is a substituent comprising a reactive group capable of reacting with the reactive group in G₂, and

G2 is a substituent comprising a reactive group capable of reacting with the reactive group in G-i.

The generation n is, typically, 1 to 6, more typically, 1 to 4, still more typically, 1 to 3. In an embodiment, n is 2.

In an embodiment, X-i is -P0₃R₆ 7.

In an embodiment, Ri is methyl.

In an embodiment, D-i and D₂ are each methylene. Typically, Gi is a d-C-15-alkyl group, optionally interrupted by one or more divalent moieties defined herein, comprising a reactive group capable of reacting with the reactive group in G₂.

In an embodiment, G1 comprises a reactive group selected from the group consisting of -X, -NH₂, -N₃, -(C=0)X, -Ph(C=0)X, -SH, -OH, -CH=CH₂, -C≡CH ^■ wherein X is a leaving group.

In an embodiment, Gi is a C-i-C-15-alkyl group comprising a -OH group. G₂ comprises a reactive group selected from the group consisting of -(C=O)X, - CH=CH₂, -C≡CH __{N H2} _M₃ -Ph(C=O)X, -SH, -X, -NCO, -NCS; wherein X is a leaving group. Typically, G₂ is -(C=O)X.

The compounds represented by the structures of formulae (III), (IV), (V) and (VI) may be obtained from commercial sources or synthesized according to synthetic methods well-known to those of ordinary skill in the art. Suitable synthetic methods known to those of ordinary skill in the art are described in well-known texts, including, but not limited to, M. B. Smith "March's Advanced Organic Chemistry: Reactions,

Mechanisms, and Structure", 7^th edition (Wiley); and Carey and Sunberg "Advanced Organic Chemistry, Part A: Structure and Mechanisms", 5^th edition (Springer) and "Advanced Organic Chemistry: Part B: Reaction and Synthesis", 5^th edition

(Springer).

Any suitable reaction conditions, including reaction vessels and equipment, for the reacting step may be selected by the ordinary-skilled artisan according to concepts known in the chemical arts.

The present disclosure relates to a method for making the hybrid nanoparticles described herein, the method comprising:

(a) contacting a heterodimer represented by M M₂,

wherein M-i and M₂ each, independently, comprise or consist of a metal or metal oxide, with a first compound that selectively attaches to Mi or M₂; and

(b) recovering the hybrid nanoparticles formed in step (a).

The heterodimer used according to the present disclosure may be obtained from commercial sources or made according to methods known in the art. For example, a suitable protocol is described in Hodges, J. M.; Morse, J. R.; Williams, M. E.;

Schaak, R. E. J. Am. Chem. Soc. 2015, 137 (49), 15493, which is herein

incorporated by reference.

The heterodimer, prior to contact with the first compound may optionally comprise organic capping groups, such as, for example, oleylamine or oleic acid.

The contacting step (a) may be carried out according to any method. For example, the heterodimer may be suspended in one or more solvents described herein to form a first mixture. The first compound may be dissolved in one or more solvents described herein to form a second mixture. The first and second mixtures may then be combined and stirred, thereby producing the hybrid nanoparticle recovered in step (b). In accordance with the present disclosure, the first compound selectively attaches to Mi or M₂ of the heterodimer. As used herein, the term "selectively attaches" with reference to a compound means that the compound has a higher binding affinity for one component than it does for the other component of the heterodimer. For example, the first compound may adhere to M-i and not M₂, or adhere to M₂ but not ML

Recovery of the hybrid nanoparticles formed in step (a) may be achieved according to methods known to those of ordinary skill. For example, the hybrid nanoparticles may be precipitated using a suitable solvent and then subject to centrifugation.

In an embodiment, the method further comprises:

(c) contacting the hybrid nanoparticles recovered in step (b) with a second compound that selectively attaches to the Mi or M₂ on which the first compound does not selectively attach; and

(d) recovering the hybrid nanoparticles formed in step (c).

The hybrid nanoparticles recovered in step (b) of the present method comprises at least one dendron derived from the first compound and may optionally comprise organic capping groups, such as, for example, oleylamine or oleic acid.

The contacting step (c) may be carried out according to any method. For example, the hybrid nanoparticles recovered in step (b) may be suspended in one or more solvents described herein to form a first mixture. The second compound may be dissolved in one or more solvents described herein to form a second mixture. The first and second mixtures may then be combined and stirred, thereby producing the hybrid nanoparticle recovered in step (d). In accordance with the present disclosure, the second compound used selectively attaches to the Mi or M₂ on which the first compound does not selectively attach. Thus, it would be understood that when the first compound selectively attaches to Μ-ι, the second compound used selectively attaches to M₂. Alternatively, when the first compound selectively attaches to M₂, the second compound used selectively attaches to M-i. Recovery of the hybrid nanoparticles formed in step (c) may be achieved according to methods known to those of ordinary skill. For example, the hybrid nanoparticles may be precipitated using a suitable solvent and then subject to centrifugation.

In an embodiment, the first and/or second compound is a compound having formula (I) or formula (II):

(II)

wherein

L-i and L₂ are each, independently, hydrocarbylene, typically C₁-C₂₀ alkylene;

Zi and Z₂ are each, independently, 0 or NH;

-i and A₂ are each, independently, H, hydrocarbyl, or

wherein Ri is hydrocarbyl, typically Ci_-4 alkyl, more typically methyl; D-i and D₂ are each, same or different, a divalent moiety, typically methylene;

n is an integer from 1 to 6; R₂ and R₃ are each, independently, H, hydrocarbyl, -(C=O)-

hydrocarbyl, or

wherein R₄ is hydrocarbyl, typically Ci_-4 alkyl;

m is an integer from 1 to 4, typically m is 2;

p is an integer from 1 to 6, typically p is 3;

, or

wherein

R₅, R₆, and R₇, are each, independently, H or hydrocarbyl;

Re, R9, R10, R11 , R12, Ri3, Ri4, Ri5, R16, Ri7, and R₁₈ are each, independently, H, OH, CN, halogen, COOH, or hydrocarbyl; and wherein L-i , L₂, R2, and R₃ are each optionally interrupted by one or more divalent moieties. mbodiment, the first compound is a compound having formula (I), wherein

l_i is hydrocarbylene;

wherein R-ι is hydrocarbyl;

D-i and D₂ are each, same or different, a divalent moiety; n is an integer from 1 to 6;

R₂ and R₃ are each, independently, hydrocarbyl or -(C=0)-hydrocarbyl; 1 is -P0₃H₂; and

wherein L-i , R₂, and R₃ are each optionally interrupted by one or more divalent moieties.

In another embodiment, the second compound is a compound having formula (II), wherein

L₂ is hydrocarbylene;

Z is 0;

wherein Ri is hydrocarbyl;

Di and D₂ are each, same or different, a divalent moiety; n is an integer from 1 to 6;

R₂ and R₃ are each H; and

wherein L₂ is optionally interrupted by one or more divalent moieties.

The present disclosure relates to a composition comprising at least one hybrid nanoparticle described herein and a liquid carrier.

The composition of the present disclosure may be a dispersion in which the at least one hybrid nanoparticle is not solubilized, but suspended in the liquid carrier.

The liquid carrier used in the composition according to the present disclosure comprises an organic solvent or a blend of organic solvents. In an embodiment, the composition consists essentially of or consists of an organic solvent or a blend of organic solvents. The blend of organic solvents comprises two or more organic solvents. Organic solvents suitable for use in the liquid carrier may be polar or non-polar, protic or aprotic solvents. Examples of suitable organic solvents include, but are not limited to, chlorinated solvents, such as, for example, chloroform and

dichloromethane; alkane solvents, such as, for example, pentane, hexane, heptane, and isomers thereof; and alcohols, such as, for example, n-propanol, isopropanol, ethanol, and methanol, and alkylene glycol monoethers.

In an embodiment, the liquid carrier comprises hexane, or isomers thereof.

The liquid carrier of the composition according to the present disclosure may further comprise a residual amount of water as a result of, for example, hygroscopic uptake by the solvents of the liquid carrier or carry-over from the reaction medium used to make the metallic nanoparticles. The amount of water in the composition is from 0 to 2 % wt., with respect to the total amount of composition. Typically, the total amount of water in the composition is from 0 to 1 % wt, more typically from 0 to 0.5 % wt, still more typically from 0 to 0.1 % wt, with respect to the total amount of the composition. In an embodiment, the composition of the present disclosure is free of water.

The amount of liquid carrier in the composition according to the present disclosure is from about 50 wt. % to about 99 wt. %, typically from about 75 wt. % to about 99 wt. %, still more typically from about 90 wt. % to about 99 wt. %, with respect to the total amount of composition.

The composition described herein may be used to produce a film. Thus, the present disclosure relates to a film comprising a plurality of hybrid nanoparticles described herein. A suitable method for making the film according to the present disclosure comprises:

(i) coating a composition described herein on the surface of a liquid

immiscible with the liquid carrier of the composition, and

(ii) removing the liquid carrier of the composition, thereby producing the film.

The step of coating a composition described herein on the surface of a liquid immiscible with the liquid carrier of the composition may be achieved using any method known to the ordinarily-skilled artisan. For example, a drop of the

composition may be spread on the surface of a liquid immiscible with the liquid carrier of the composition.

The liquid immiscible with the liquid carrier of the composition may be any solvent or blend of solvents that is immiscible with the liquid carrier of the composition. In an embodiment, the liquid immiscible with the liquid carrier of the composition is diethylene glycol.

Subsequent to the coating step, the step of removing the liquid carrier of the composition may be achieved according to any method known to the ordinarily- skilled artisan. For example, the liquid carrier of the composition may be allowed to evaporate under temperatures and pressures selected by the artisan based on the liquid carrier to be removed. In an embodiment, the step of removing the liquid carrier of the composition is carried out under ambient temperature and pressure.

The various properties of the hybrid nanoparticles of the present disclosure, and of films containing the hybrid nanoparticles, may be determined using methods and instruments known to those of ordinary skill in the art.

For example, the effective diameter of the hybrid nanoparticles may be determined using one or more techniques and instruments known to those of ordinary skill in the art. For example, a combination of techniques including NMR and UV-Vis

spectroscopies, thermogravimetric analysis (TGA), transmission electron microscopy (TEM) and small-angle X-ray scattering (SAXS) may be used. The hybrid nanoparticles, compositions, methods and processes, and films according to the present disclosure are further illustrated by the following non-limiting examples.

Examples

The materials used in the following examples, unless otherwise stated, are summarized below.

1 -Octadecene (technical grade, 90 %) was purchased from Acros Organics. Oleic acid (technical grade, 90 %) was purchased from Sigma-Aldrich. 2,2- Dimethoxypropane (98+%), bis-MPA (98%), pyridine (reagent), Dowex H⁺ ion exchange resin (200-400 mesh), and oleylamine (80-90%) were purchased from Acros and used without further purification. Ν,Ν'-Dicyclohexylcarbodiimide (DCC, 99%), 4-dimethylaminopyridine (DMAP, 99%), 1 1 -mercaptoundecan-1 -ol 8 (98%) were purchased from Aldrich and used without further purification. Solvents were ACS grade or higher. CH₂CI₂ was dried over CaH₂ and freshly distilled before used. In general, unless otherwise stated, ¹H NMR (500 MHz) and ¹³C NMR (126 MHz) spectra were recorded on Bruker UNI500 or BIODRX500 NMR spectrometer. ¹ H and ¹³C chemical shifts (5) are reported in ppm while coupling constants (J) are reported in Hertz (Hz). The multiplicity of signals in ¹H NMR spectra is described as "s" (singlet), "d" (doublet), T (triplet), "q" (quartet),"p" (pentet), "dd" (doublet of doublets) and "m" (multiplet). All spectra were referenced using solvent residual signals

(CDCI₃: ¹ H, 5 7.27 ppm; ¹³C, 5 77.2 ppm, MeOD: ¹H, 5 3.31 ppm; ¹³C, 549.00 ppm). 2D one bond heteronuclear correlation ¹H-¹³C HSQC experiment was used to confirm NMR peak assignments. Reaction progress was monitored by thin-layer chromatography using silica gel coated plates or ¹ H NMR. Compounds were purified by filtration, precipitation, crystallization and/or flash column chromatography using silica gel (Acros Organics, 90 A, 35-70 pm) as indicated.

Matrix-assisted laser desorption/ionization time of flight (MALDI-TOF) mass spectrometry was performed on Bruker Ultraflex III (Maldi-Tof-Tof) mass

spectrometer using dithranol as matrix.

TEM micrographs were collected using a JEOL 1400 microscope operated at 120 kV. The TEM was calibrated using a MAG^*I^*CAL® TEM calibration standard.

Example 1. Synthesis of a compound having formula (I).

The synthesis of a compound having formula (I) commenced with the synthesis of intermediate 2, shown in Scheme 1 below.

Scheme 1

To a stirred solution of bis-MPA (18 g, 136.3 mmol) in DMF (100 mL) was added KOH (8.2 g, 146.6 mmol). The resulting solution was stirred at 100 °C for 2 h after which propargyl bromide (20.3 g, 137 mmol) was added dropwise (over 30 min) and stirring continued for an additional 48 h. The solution was cooled to 23 °C, filtered and DMF was evaporated under reduced pressure. The residue was dissolved in chloroform (70 mL), filtered and the filtrate placed in the fridge at -10 °C for 2 h. The resulting white precipitate was quickly filtered and dried to afford prop-2-yn-1 -yl 3- hydroxy-2-(hydroxymethyl)-2-methylpropanoate 2 (13.8 g, 60%) as a white solid. ¹H NMR (CDCI3) 54.73 (d, J = 2.5 Hz, 2H), 3.88 (d, J = 1 1 .4 Hz, 2H), 3.70 (d, J = 13.1 Hz, 2H), 3.30-2.74 (m, 2H), 2.49 (t, J = 2.4 Hz, 1 H), 1 .09 (s, 3H); ¹³C NMR (CDCI₃) δ 175.13, 77.47, 75.37, 67.33, 52.56, 49.49, 17.12. The synthesis of compound 6 was then conducted according to Scheme 2 below.

6

Scheme 2.

To a stirred solution of prop-2-yn-1 -yl 3-hydroxy-2-(hydroxymethyl)-2- methylpropanoate, 2 (8.0 g, 46.5 mmol), DMAP (2.27 g, 18.6 mmol) and pyridine (1 1 .0 g, 139.4 mmol) in CH₂CI₂ (100 mL) was added 2,2,5-trimethyl-1 ,3-dioxane-5- carboxylic anhydride 3 (36.8 g, 1 1 1 .5 mmol) and the resulting mixture stirred for 24 h. Compound 3 was synthesized according to published procedures (see Ihre, H.; Hult, A.; Frechet, J. M. J.; Gitsov, I. Macromolecules 1998, 31, 4061 ; and Gillies, E. R.; Frechet, J. M. J. J. Am. Chem. Soc. 2002, 124, 14137). The reaction was quenched with 5 mL water and diluted with additional CH2CI2 (200 mL), washed with NaHS0₄ (2 x 100 mL), Na₂C0₃ (2 x 100 mL) and brine (50 mL), dried over anhydrous MgS0₄ and concentrated under reduced pressure. The residue was purified by column chromatography (S1O2, 0 - 50% EtOAc:hexanes) to afford the compound 4 (17.8 g, 79%). ¹H NMR (CDCI₃) δ 4.72 (d, J = 2.6 Hz, 2H), 4.37-4.28 (m, 4H), 4.15 (d, J = 12.0 Hz, 4H), 3.62 (d, J = 10.9 Hz, 4H), 2.46 (t, J = 2.4 Hz, 1 H), 1 .41 (s, 6H), 1 .36 (s, 6H), 1 .31 (s, 3H), 1 .15 (s, 6H); ¹³C NMR (CDCI₃) δ 173.58, 171 .92, 98.18, 77.30, 75.43, 66.06, 66.03, 65.35, 52.76, 46.90, 42.15, 25.1 1 , 22.31 , 18.60, 17.68; MALDI-TOF (m/z): [M+Na]⁺ calcd. for C₂₄H36O₁₀Na, 507.2206; found 507.282.

To a stirred solution of 2-methyl-2-((prop-2-yn-1 -yloxy)carbonyl)propane-1 ,3-diyl bis(2,2,5-trimethyl-1 ,3-dioxane-5-carboxylate), 4 (15.0 g, 31 .0 mmol) in MeOH was added DOWEX resin (10 g) and the resulting suspension stirred at 40 °C for 2 h, after which ¹³C NMR showed the disappearance of acetonide quaternary carbon signal (~98 ppm). The suspension was filtered and the filtrate concentrated under reduced pressure to afford compound 5 (12.46 g, > 99%). ¹ H NMR (CDCI₃) δ 4.74 (d, J = 2.4 Hz, 2H), 4.45 (d, J = 1 1 .1 Hz, 2H), 4.29 (d, J = 1 1 .2 Hz, 2H), 3.84 (dd, J = 10.3, 7.6 Hz, 4H), 3.70 (dd, J = 1 1 .4, 9.9 Hz, 4H), 2.71 (s, 4H), 2.49 (t, J = 2.4 Hz, 1 H), 1 .33 (s, 3H), 1 .05 (s, 6H); ¹³C NMR (CDCI₃) δ 175.09, 172.33, 77.36, 75.66, 66.97, 66.95, 64.80, 52.86, 49.90, 46.48, 18.04, 17.21 ; MALDI-TOF (m/z): [M+Na]⁺ calcd. for C₁₈H28O₁₀Na, 427.1580; found 427.275. To a stirred solution of compound 5, DMAP and pyridine in CH2CI2 (50 mL) was added stearic anhydride and the resulting mixture stirred for 12 h. The reaction mixture was diluted with additional CH₂CI₂ (50 mL), washed with 1 N HCI (3 x 50 mL), dried over anhydrous MgSO₄, filtered and filtrate concentrated under reduced pressure. The residue was purified by column chromatography (S1O2, 0 - 50%

EtOAc:hexanes) to afford compound 6 (6.1 g, 88%). Compound 6 was further purified by repeated precipitation from CHCI₃/MeOH). ¹H NMR (500 MHz, CDCI₃) δ 4.71 (d, J = 2.4 Hz, 2H), 4.28 (d, J = 1 1 .1 Hz, 2H), 4.24 (d, J = 1 1 .1 Hz, 2H), 4.22- 4.12 (m, 8H), 2.50 (t, J = 2.0 Hz, 1 H), 2.28 (t, J = 7.6 Hz, 8H), 1 .62-1.54 (m, 8H), 1 .31 -1.23 (m, 1 15H), 1 .22 (s, 6H), 0.87 (t, J = 6.7 Hz, 12H); ¹³C NMR (CDCI3) δ 173.33, 172.20, 171 .56, 77.21 , 75.67, 65.75, 65.14, 52.90, 46.81 , 46.56, 34.18, 32.08, 29.86, 29.83, 29.81 , 29.79, 29.65, 29.51 , 29.44, 29.29, 25.01 , 22.84, 17.93, 17.60, 14.26; MALDI-TOF (m/z): [M+Na]⁺ calcd. for C₉oH₁₆₄0₁₄Na, 1492.2019; found 1491 .808.

7

12-Azidododecylphosphonic acid (purchased from Alfa-Aesar) was coupled to compound 6 to form a compound having formula (I), compound 7. To a stirred solution of 12-azidododecylphosphonic acid (4.14 mmol), compound 6 (4.14 mmol) and CuS0₄'5H₂0 (0.42g, 1 .66 mmol) in THF/H₂0 = 4: 1 (8 ml_) was added sodium ascorbate (0.44g, 2.22 mmol) and the resulting mixture stirred at 65 °C for 6 h under microwave irradiation (constant temperature mode). The solvent was evaporated, residue was dissolved in CHCI3 (100 ml_) and washed with 1 N HCI (3 x 100 ml_). The organic layer was dried over anhydrous Na₂S0₄, filtered and the filtrate concentrated under reduced pressure to afford the desired compound 7. The residue was redissolved in the smallest possible amount of warm CHCI3 and mixed with MeOH to induce the precipitation. The precipitate was collected by filtration and dried to obtain a white solid (0.5g, 90%). ¹H NMR (CDCI₃) δ 7.72 (s, 1 H), 5.25 (s, 2H), 4.36 (t, J = 7.3 Hz, 2H), 4.23 (q, J = 1 1 .1 Hz, 4H), 4.14 (t, J = 8.4 Hz, 8H), 2.27 (t, J = 7.5 Hz, 8H), 1 .98 - 1 .83 (m, 2H), 1 .83 - 1 .67 (m, 2H), 1 .57 (p, J = 7.3 Hz, 1 1 H), 1 .47 - 1.18 (m, 133H), 1.17 (s, 6H), 0.87 (t, J = 6.7 Hz, 12H); ¹³C NMR (CDCI3) δ 173.34, 172.27, 172.13, 65.64, 65.09, 58.48, 50.71 , 46.79, 46.49, 34.16, 32.06, 30.71 , 30.60, 30.39, 29.84, 29.82, 29.80, 29.78, 29.64, 29.61 , 29.52, 29.49, 29.44, 29.28, 29.21 , 29.14, 26.67, 25.00, 22.82, 22.24, 17.89, 17.65, 14.24; MALDI- TOF (m/z): [M+Na]⁺ calcd. for

1783.3731 ; found 1783.696. Example 2. Synthesis of a compound having formula (II).

Compounds having formula (II) were synthesized according to following Scheme 3.

12 13, G2

Scheme 3.

11,11'-Disulfanediylbis(undecan-1 -ol) 9. To a stirred solution of 1 1 - mercaptoundecan-1 -ol 8 (5.0g, 24.5 mmol) in CH₂CI₂ was added a solution of iodine in CH₂CI₂ (50 mL) until the solution remained purple/brown and the resulting solution was stirred overnight. The reaction mixture was diluted with CH₂CI₂ (100 mL) and washed with 1 M sodium thiosulfate (2 x 100 mL). The organic layer was dried over Na₂S0₄ and concentrated under reduced pressure to afford pure 1 1 , 1 1 '- disulfanediylbis(undecan-l -ol) 9 (white powder, 4.72g, 95%). ¹H NMR (CDCI₃) 5 3.64 (t, J = 6.6 Hz, 4H), 2.68 (t, J = 7.3Hz, 4H), 1 .67 (p, J = 7.4 Hz, 4H), 1 .61 - 1.51 (m, 4H), 1 .39 - 1 .25 (m, 28H); 13C NMR (CDCI₃) δ 77.41 , 77.16, 76.91 , 63.23, 39.39, 32.96, 29.72, 29.65, 29.63, 29.57, 29.37, 28.67, 25.89.

Disulfanediylbis(undecane-11 ,1 -diyl)bis(2,2,5-trimethyl-1 ,3-dioxane-5- carboxylate) 10. To a stirred solution of 1 1 , 1 1 '-disulfanediylbis(undecan-1 -ol) 9 (2.5 g, 6.2 mmol) in CH₂CI₂ (30 mL) was added 2,2,5-trimethyl-1 ,3-dioxane-5-carboxylic anhydride (5.0 g, 15 mmol), pyridine (1 .45g, 22 mmol) and DMAP (0.24g, 2 mmol) and the resulting mixture was stirred at rt for an additional 12h. The reaction was quenched by water (5 mL), diluted with CH₂CI₂ and washed with water (3 x 100 mL). The Organic layer was dried over Na₂SO₄, concentrated under reduced pressure and the residue purified by flash chromatography (SiO₂, 0-10% EtOAc/Hexanes) to afford pure disulfanediylbis(undecane-1 1 , 1 -diyl)bis(2,2,5-trimethyl-1 ,3-dioxane-5- carboxylate) 10 (colorless oil, 4.03g, 91 %). ¹H NMR (CDCI3) 54.17 (d, J = 1 1 .7 Hz, 4H), 4.12 (t, J = 6.7 Hz, 4H), 3.62 (d, J = 1 1 .8 Hz, 4H), 2.67 (t, J = 7.5 Hz, 3H), 1 .71

- 1 .58 (m, 8H), 1 .42 (s, 6H), 1 .38 (s, 6H), 1 .37 - 1 .23 (m, 28H), 1 .19 (s, 6H); ¹³C NMR (CDCI3) δ 174.38, 98.14, 66.15, 65.06, 41 .90, 39.30, 29.60, 29.35, 29.32,

28.70, 28.65, 25.94, 24.31 , 23.28, 18.89, 0.12.

Disulfanediylbis(undecane-11 ,1 -diyl) bis(3-hydroxy-2-(hydroxymethyl)-2- methylpropanoate) 11. To a stirred solution of disulfanediylbis(undecane-1 1 ,1 - diyl)bis(2,2,5-trimethyl-1 ,3-dioxane-5-carboxylate) 10 (1 .2 g 1 .7 mmol) in MeOH was added DOWEX resin (2 g) and the resulting suspension stirred at 50 °C for 7 h, after which ¹³C NMR showed the disappearance of the acetonide quaternary carbon signal (~98 ppm). The suspension was filtered through Celite and the filtrate concentrated under reduced pressure to afford title compound 11 (white solid, 1 .06g, 99%). ¹ H NMR (CDCI₃) 54.13 (t, J = 6.7 Hz, 4H), 3.87 (d, J = 1 1 .2 Hz, 4H), 3.69 (d, J = 1 1 .3 Hz, 4H), 3.02 (s, 4H), 2.66 (t, J = 7.4 Hz, 4H), 1 .64 (h, J = 6.6 Hz, 8H), 1 .39

- 1 .23 (m, 28H), 1 .05 (s, 6H); ¹³C NMR (CDCI₃) δ 176.09, 68.10, 65.29, 49.26, 39.29, 29.56, 29.31 , 29.29, 28.63, 28.60, 25.95, 17.28, 0.10. (((Disulfanediylbis(undecane-11,1 -diyl))bis(oxy))bis(carbonyl))bis(2- methylpropane-2,1,3-triyl) tetrakis(2,2,5-trimethyl-1 ,3-dioxane-5-carboxylate)

12. The title compound was prepared according to the procedure used in the conversion of compound 9 to compound 10. The molecule was taken into next step without isolation.

(((Disulfanediylbis(undecane-11,1 -diyl))bis(oxy))bis(carbonyl))bis(2- methylpropane-2,1,3-triyl) tetrakis(3-hydroxy-2-(hydroxymethyl)-2- methylpropanoate) 13. The title compound was prepared according to the procedure used in the conversion of compound 10 to compound 11. (Colorless oil, 1 .42g, 99%). ¹ H NMR (CDCI₃) δ 4.43 (d, J = 1 1 .1 Hz, 4H), 4.26 (d, J = 1 1 .1 Hz, 4H), 4.13 (t, J = 6.7 Hz, 4H), 3.83 (d, J = 4.2 Hz, 4H), 3.81 (d, J = 4.1 Hz, 4H), 3.73 - 3.67 (m, 8H), 3.07 (s, 8H), 2.68 (t, J = 7.3 Hz, 4H), 1 .72 - 1 .59 (m, 8H), 1 .39 - 1 .24 (m, 34H), 1 .05 (s, 12H); ¹³C NMR (CDCI3) δ 175.26, 173.19, 67.86, 65.82, 65.04, 49.86, 46.50, 39.34, 29.61 , 29.58, 29.34, 29.32, 28.64, 25.98, 18.30, 17.27.

Example 3. Production of inventive hybrid nanoparticles.

Fe₃0₄-Pt heterodimers were prepared by using platinum nanocubes as seeds in accordance with a known protocol described in Hodges, J. M.; Morse, J. R.;

Williams, M. E.; Schaak, R. E. J. Am. Chem. Soc. 2015, 137 (49), 15493. The average size of the platinum nanocube seed was 7.3 ± 0.5 nm (face diagonal length of inorganic part) measured from TEM images (FIG. 2). The average size of the Fe₃0₄ body was 15.4 ± 2.2 nm (inorganic part).

Ligand exchange on the oleic acid-capped iron oxide part of heterodimers was performed using 1 mL of NPs in hexanes at 10 mg/mL added to 5 mL of chloroform in which 10 mg of compound 7 was dissolved. The reaction mixture was stirred overnight at 35 °C. The reaction was stopped by precipitation of the NPs using methanol. After centrifugation, the NPs were redispersed in chloroform. This procedure was repeated 3 times to ensure the complete removal of any unbound organic molecules.

The effect of ligand exchange during the first step (with compound 7) was clearly seen from the significant increase in surface to closest surface inter-particle spacing (from 1 .0 nm to 2.4 nm as measured between two Fe₃0₄ bodies from TEM images). Ligand exchange on the oleic acid capped Pt part of heterodimers was performed using 1 mL of NPs in hexanes at 10 mg/mL added to 5 mL of chloroform in which 10 mg of compounds 9, 11 , or 13 was dissolved. Each reaction was stirred overnight at 35 °C. Each reaction was stopped by precipitation of the NPs with excess methanol. After centrifugation, the NPs were redispersed in chloroform. This procedure was repeated 2 times to ensure the complete removal of any unbound organic molecules. Example 3. Formation of films by self-assembly of inventive hybrid nanoparticles.

Self-assembly of particles into layered architectures was achieved on a polar liquid- air interface in a Teflon well. Diethylene glycol was used as the subphase on which a dispersion of the particles in hexanes was deposited. The Teflon well was covered with glass to allow slow evaporation of the hexanes layer. After two hours, the NPs self-assembled into superlattice films on the liquid-air interface. The solid films were then transferred to a solid substrate by "stamping" (by using a solid wafer/TEM grid to touch from top) and were visualized.

The order of the self-assembled layer of particles became progressively better after each ligand exchange step. Self-assembly of heterodimers not having dendrons over liquid-air interface revealed an irregular structure where no long range order is present (see FIG. 3a) which is not surprising since the sample has a relatively high polydispersity (14% on Fe₃0₄ and 7.3% on Pt). After ligand exchange with 7, the inter-particle distances (surface to surface) between the NPs increased to 2.4 nm as the dendron is much larger than original ligand oleic acid. As seen from the TEM image of a self-assembled monolayer and bilayer, shown in FIG. 3b, this step significantly improves the short range order of such heterodimers. Without wishing to be bound by theory, the improvement of self-assembly properties observed here is believed to be introduced by the large size and monodisperse nature of the dendritic ligand as it introduces a thick, yet flexible organic shell and is able to counterbalance the size and shape irregularity present in the inorganic parts.

Ligand exchange on the platinum part was carried out as second step using ligands 9, 11 and 13 as described in Example 2. After ligand exchange, samples were examined by the above mentioned self-assembly technique and the monolayers were studied. No significant improvement in the assembly properties was observed when compounds 9 and 11 were used (FIG. 4 and FIG. 5). However, after ligand exchange step with compound 13 on the Pt part, a further increase in interparticle distance to 4.4 nm and a dramatic improvement in their self-assembly were observed. Such modification introduced both long range and short range order as can be seen from their self-assembled monolayer (FIG. 3c) and multilayer structures (FIG. 3d). The enhancement in superlattice film crystallinity may be explained by surface treatment with large dendritic molecules which can influence the assembly process in several ways. Firstly, the effective polydispersity of the heterodimer is improved during the two-step ligand exchange process where the surface is coated by large yet monodisperse ligands, i.e., the resulting NP hybrid is more uniform than the heterodimer was before ligand exchange. Secondly, the introduction of a thick soft layer may grant the hybrid system the ability to better accommodate the size irregularity due to flexible nature of the dendritic ligands or allow rotations during the solvent evaporation process to reduce the in-plane size irregularity by pointing Pt part out of the assembly plane.

The improvement in effective polydispersity can be estimated if the ligand length is accounted during a calculation of the total size polydispersity. For example, if the sample has an inorganic core with an average diameter of 1 5.4 ± 2.2 nm, then its polydispersity equals to 2.2/1 5.4x 1 00 % = 14.2 %. As-synthesized NPs have ligands (derived from oleic acid) with an effective length of 0.5 nm (obtained by dividing an interparticle separation 1 nm in half) and therefore, the effective polydispersity of the same sample is 2.2/(1 5.4 + 1 ) = 1 3.4 %.

Dendritic ligands introduce much larger interparticle separation of 4.4 nm. The effective length of the dendritic ligand is 4.4/2 = 2.2 nm and the average diameter of the hybrid is 1 5.4 + 4.4 = 1 9.8. The original deviation (± 2.2 nm) is unaffected due to a strictly monodisperse nature of the dendritic ligands. Considering these values, the effective polydispersity of the hybrid system (inventive hybrid nanoparticles) becomes 2.2/1 9.8x 1 00 % = 1 1 %, which is significantly lower (improved) compared to the particles devoid of dendrons (1 3.4 %). Surprisingly, a unique mode of assembly of the inventive hybrid nanoparticles was observed that may be attributed to their amphiphilic nature. Namely, the particles assemble exclusively with the Pt part pointing down towards the diethylene glycol layer. This is in excellent agreement with the fact that the Pt part carries polar ligands terminated with hydroxyl end-groups that can establish favorable interaction with diethylene glycol, whereas the iron oxide part is coated with nonpolar dendrons, which prefer to be away from the polar subphase.

FIG. 6 shows a SEM image of a self-assembled monolayer picked up by the

"stamping" method which clearly shows the Pt part (brighter spots) to be on top (pointing up). Since the "stamping" method involves touching a TEM grid to fully- assembled layered structures from the top, the iron oxide part is directly in contact with the surface of the grid and the Pt part is positioned away from it. This is further evidence that asymmetric functionalization with dendritic ligands of different polarity guide the orientation of NPs during the self-assembly process.

Owing to their property that the orientation can be guided during the self-assembly process, the hybrid nanoparticles of the present disclosure hold an enormous potential to form layered membranes where the orientation of NP assemblies is controlled by the nature of their surface binding ligands and assembly methods. Types of membranes include systems where the orientation of each layer is either same or opposite of each other, such as, for example, in a bi-layer structure.

Claims

WHAT IS CLAIMED IS:

1 . A hybrid nanoparticle comprising:

a heterodimer represented by M-|M₂,

wherein M-i and M₂ each, independently, comprise or consist of a metal or metal oxide;

at least one dendron attached to Mi and/or

at least one dendron attached to M₂.

2. The hybrid nanoparticle according to claim 1 , wherein M-i comprises or consists of a metal, typically a transition metal, more typically a transition metal selected from the group consisting of gold, silver, and platinum, still more typically platinum.

3. The hybrid nanoparticle according to claim 1 or 2, wherein M₂ comprises or consists of a metal oxide, typically a transition metal oxide, more typically a transition metal oxide selected from the group consisting of iron oxide, manganese oxide, and titanium oxide, still more typically iron oxide having the formula Fe₃0₄.

4. The hybrid nanoparticle according to any one of claims 1 -3, wherein the at least one dendron attached to Mi and/or the at least one dendron attached to M₂ is derived from a compound having formula (I) or formula (II):

(II)

wherein

Li and L₂ are each, independently, hydrocarbylene, typically Ci-C₂₀ alkylene; Ζ-ι and Z₂ are each, independently, O or NH;

Ai and A₂ are each, independently, H, hydrocarbyl, or - R

-kR

n wherein Ri is hydrocarbyl, typically Ci_-4 alkyl, more typically methyl;

Di and D₂ are each, same or different, a divalent moiety, typically methylene;

n is an integer from 1 to 6;

R₂ and R₃ are each, independently, H, hydrocarbyl, -(C=O)-hydrocarbyl, or

wherein R₄ is hydrocarbyl, typically Ci_-4 alkyl;

m is an integer from 1 to 4, typically m is 2;

p is an integer from 1 to 6, typically p is 3;

Xi is -COOR5, -POsReRy, -CN,

or wherein

R₅, R₆, and R₇, are each, independently, H or hydrocarbyl;

R₈, R₉, R10, R11 , R12, Ri3, Ri4, Ri5, R16, Ri7, and R₁₈ are each,

independently, H, OH, CN, halogen, COOH, or hydrocarbyl; and wherein L-ι , L₂, R2, and R₃ are each optionally interrupted by one or more divalent moieties.

5. The hybrid nanoparticle according to any one of claims 1 -4, wherein a dendron derived from the compound having formula (I) is attached to M₂.

6. The hybrid nanoparticle according to claim 5, wherein

l_i is hydrocarbylene;

Zi is

IS

wherein R-i is hydrocarbyl;

Di and D₂ are each, same or different, a divalent moiety; n is an integer from 1 to 6;

R₂ and R₃ are each, independently, hydrocarbyl or -(C=0)-hydrocarbyl;

wherein L-i , R₂, and R₃ are each optionally interrupted by one or more divalent moieties.

7. The hybrid nanoparticle according to any one of claims 1 -6, wherein a dendron derived from the compound having formula (II) is attached to M-i .

8. The hybrid nanoparticle according to claim 7, wherein

l_2 is hydrocarbylene;

Z₂ is 0;

A₂ is H or

wherein R-i is hydrocarbyl;

D-i and D₂ are each, same or different, a divalent moiety;

n is an integer from 1 to 6;

R₂ and R₃ are each H; and

wherein L₂ is optionally interrupted by one or more divalent moieties.

A compound having formula (I) or (II):

wherein

l_i and L₂ are each, independently, hydrocarbylene, typically Ci-C₂o alkylene;

Z-i and Z₂ are each, independently, 0 or NH;

-i and A₂ are each, independently, H, hydrocarbyl, or

wherein R-ι is hydrocarbyl, typically Ci_-4 alkyl, more typically methyl;

D-i and D₂ are each, same or different, a divalent moiety, typically methylene;

n is an integer from 1 to 6;

R₂ and R₃ are each, independently, H, hydrocarbyl, -(C=O)-hydrocarbyl, or

wherein R₄ is hydrocarbyl, typically Ci_-4 alkyl;

m is an integer from 1 to 4, typically m is 2;

p is an integer from 1 to 6, typically p is 3;

Xi is -COOR5, -POsReRy, -CN,

wherein

R₅, R₆, and R₇, are each, independently, H or hydrocarbyl;

Re, R₉, R10, R11 , R12, Ri3, Ri4, Ri5, R16, Ri7, and R₁₈ are each, independently, H, OH, CN, halogen, COOH, or hydrocarbyl; and wherein L-i , L₂, R₂, and R₃ are each optionally interrupted by one or more divalent moieties.

10. The compound according to claim 9, wherein the compound is a compound having formula (II):

wherein

l_₂ is hydrocarbylene, typically C-₁-C₂₀ alkylene;

Z₂ is 0 or NH;

A₂ is H, hydrocarbyl, or

wherein Ri is hydrocarbyl, typically Ci_-4 alkyl, more typically methyl;

D-i and D₂ are each, same or different, a divalent moiety, typically methylene;

n is an integer from 1 to 6;

R₂ and R₃ are each H; and

wherein L₂, R₂, and R₃ are each optionally interrupted by one or more divalent moieties.

1 1 . A method for making the hybrid nanoparticles according to any one of claims 1 -8, the method comprising:

(a) contacting a heterodimer represented by M M₂,

wherein Mi and M₂ each, independently, comprise or consist of a metal or metal oxide, with a first compound that selectively attaches to Mi or M₂; and

(b) recovering the hybrid nanoparticles formed in step (a).

The method according to claim 1 1 , further comprising:

(c) contacting the hybrid nanoparticles recovered in step (b) with a second compound that selectively attaches to the Mi or M₂ on which the first compound does not selectively attach; and

(d) recovering the hybrid nanoparticles formed in step (c).

13. The method according to claim 1 1 or 12, wherein M-i comprises or consists of a metal, typically a transition metal, more typically a transition metal selected from the group consisting of gold, silver, and platinum, still more typically platinum.

14. The method according to any one of claims 1 1 -13, wherein M₂ comprises or consists of a metal oxide, typically a transition metal oxide, more typically a transition metal oxide selected from the group consisting of iron oxide, manganese oxide, and titanium oxide, still more typically iron oxide having the formula Fe₃0₄.

15. The method according to any one of claims 1 1 -14, wherein the first and/or second compound is a compound having formula (I) or formula (II):

wherein

l_i and L₂ are each, independently, hydrocarbylene, typically C1-C20 alkylene;

Z-i and Z₂ are each, independently, 0 or NH;

-i and A₂ are each, independently, H, hydrocarbyl, or R

R

wherein Ri is hydrocarbyl, typically Ci_-4 alkyl, more typically methyl; D-ι and D₂ are each, same or different, a divalent moiety, typically

methylene;

n is an integer from 1 to 6;

R₂ and R₃ are each, independently, H, hydrocarbyl, -(C=O)-hydrocarbyl, or

wherein R₄ is hydrocarbyl, typically Ci_-4 alkyl;

m is an integer from 1 to 4, typically m is 2;

p is an integer from 1 to 6, typically p is 3;

Xi is -COOR5, -POsReRy, -CN,

wherein

R₅, R₆, and R₇, are each, independently, H or hydrocarbyl;

Re, R9, R-io, R11 , R12, R-I 3, Ri4, Ri5, R16, Ri7, and R-is are each, independently, H, OH, CN, halogen, COOH, or hydrocarbyl; and wherein L-i , L₂, R2, and R₃ are each optionally interrupted by one or more divalent moieties.

16. The method according to any one of claims 1 1 -15, wherein the first compound is a compound having formula (I),

wherein

L-i is hydrocarbylene;

Zi is O;

IS

wherein R-i is hydrocarbyl;

D-i and D₂ are each, same or different, a divalent moiety;

n is an integer from 1 to 6;

R₂ and R₃ are each, independently, hydrocarbyl or -(C=0)-hydrocarbyl;

wherein L-i , R₂, and R₃ are each optionally interrupted by one or more divalent moieties.

The method according to any one of claims 1 1 -16, wherein the second pound is a compound having formula (II),

wherein

l_2 is hydrocarbylene;

wherein R-i is hydrocarbyl;

D-i and D₂ are each, same or different, a divalent moiety;

n is an integer from 1 to 6;

R₂ and R₃ are each H; and

wherein L₂ is optionally interrupted by one or more divalent moieties.

18. A film comprising a plurality of hybrid nanopartides according to any one of claims 1 -8 or hybrid nanopartides made by the method according to any one of claims 1 1 -17.