Ag Nanoclusters with Surface Azides as an Easily Functionalized Platform for Diverse Chemical Applications.

Modifying atomically precise nanocluster surfaces while maintaining the cluster core remains a key challenge. Herein, the synthesis, structure, and properties of two targeted Ag nanoclusters (NCs) with eight surface azide moieties, [CO@Ag(SBu)(m-N-CHCOO)(DMF)] (1-m) and [CO@Ag(SBu)(p-N-CHCOO)(DMF)] (1-p) are reported, where DMF is N,N-dimethylformamide. These AgNCs are designed to undergo cluster surface strain-promoted azide-alkyne cycloaddition (CS-SPAAC) reactions, introducing new functionality to the cluster surface.

Controlling the Structure, Properties and Surface Reactivity of Clickable Azide-Functionalized Au (SR) Nanocluster Platforms Through Regioisomeric Ligand Modifications.

To fine-tune structure-property correlations of thiolate-protected gold nanoclusters through post-assembly surface modifications, we report the synthesis of the o, m, and p regioisomeric forms of the anionic azide-functionalized [Au (SCH CH -C H -N ) ] platform. They can undergo cluster-surface strain-promoted alkyne-azide cycloaddition (CS-SPAAC) chemistry with complementary strained-alkynes. Although their optical properties are similar, the electrochemical properties appear to correlate with the position of the azido group.

Preparation and luminescence properties of a M heterometallic coinage metal chalcogenide cluster.

A hexadeca-nuclear, N-heterocyclic carbene stabilized gold(i)-copper(i)-sulfido cluster is reported, which emits yellow-orange in the solid state. The nature of this emission is examined, supported by combined theoretical and spectroscopic studies.

Facile synthesis of a hexanuclear zinc-acetato-trimethylsilylphosphinidene cluster: a single-source precursor to ZnP nanoparticles.

The selective synthesis of the zinc-acetato-phosphinidene cluster [Zn(μ-PSiMe)(OAc)(NCH)] 1 is presented. The cluster serves as a stable, single-source precursor to yield soluble zinc phosphide nanoparticles via P-Si bond activation and AcOSiMe elimination when heated in oleylamine or other donor solvents.

Golden Opportunity: A Clickable Azide-Functionalized [Au(SR)] Nanocluster Platform for Interfacial Surface Modifications.

Ultrasmall atomically precise monolayer-protected gold thiolate nanoclusters are an intensely researched nanomaterial framework, but there is a lack of a system that can be directly synthesized and undergo interfacial surface chemistry. We report an [Au(SCHCH--CH-N)] nanocluster platform with azide moieties appended onto each surface ligand. The structure of this surface reactive cluster has been confirmed by single-crystal X-ray crystallography, mass spectrometry and ultraviolet visible, infrared and nuclear magnetic resonance spectroscopies.

Highly Electron-Deficient Pyridinium-Nitrones for Rapid and Tunable Inverse-Electron-Demand Strain-Promoted Alkyne-Nitrone Cycloaddition.

Highly accelerated inverse-electron-demand strain-promoted alkyne-nitrone cycloaddition (IED SPANC) between a stable cyclooctyne (bicyclo[6.1.0]nonyne (BCN)) and nitrones delocalized into a -pyridinium functionality is reported, with the most electron-deficient "pyridinium-nitrone" displaying among the most rapid cycloadditions to BCN that is currently reported.

Tuning the Metal/Chalcogen Composition in Copper(I)-Chalcogenide Clusters with Cyclic (Alkyl)(amino)carbene Ligands.

A series of phosphorescent homo- and heterometallic copper(I)-chalcogenide clusters stabilized by cyclic (alkyl)(amino)carbene ligands [CuM(μ-E)(CAAC)] (M = Cu, Ag, Au; E = S, Se) has been synthesized by the reaction of the new copper(I) trimethylsilylchalcogenolate compounds [(CAAC)CuESiMe] with ligand-supported group 11 acetates. The clusters are emissive at 77 K in solution and the solid state, with emission colors that depend on the metal/chalcogen composition. Electronic structure calculations point to a common [(M+E)LCT] emissive state for the series.

NHC Ligated Group 11 Metal-Arylthiolates Containing an Azide Functionality Amenable to "Click" Reaction Chemistry.

The reaction of N-heterocyclic carbene (NHC) Group 11 metal complexes, [(NHC)M-X] (X = chloride, acetate), with the new azide-modified arylthiol 1-HSCH-2,5-Me-4-NCH-CH, 1 (for M = Au; X = Cl), or 1-MeSiSCH-2,5-Me-4-NCH-CH, 2 (for M = Cu, X = Cl; M = Ag, X = OAc), affords the "clickable" NHC-metal thiolates [( Pr-bimy)Au-(1-SCH-2,5-Me-4-NCH-CH)], 5; [(IPr)Au-(1-SCH-2,5-Me-4-NCH-CH)], 6; [(IPr)Ag-(1-SCH-2,5-Me-4-NCH-CH)], 7; and [(IPr)Cu-(1-SCH-2,5-Me-4-NCH-CH)], 8 ( Pr-bimy = 1,3-di-isopropylbenzimidazol-2-ylidene, IPr = 1,3-bis(2,6-di-iso-propylphenyl)imidazol-2-ylidene). Single-crystal X-ray analysis of all metal complexes show that they are two-coordinate, nearly linear, with a terminally bonded thiolate ligand possessing an accessible azide (-N) moiety. The strain-promoted alkyne-azide cycloaddition (SPAAC) reaction of complex 6 with bicyclo[6.

(GeP): a binary analogue of P as a precursor to the ternary cluster anion [Cd(GeP)].

The novel binary P analogue (GeP) proved to be a suitable precursor for heteroatomic cluster synthesis. Over time in solution, it rearranges to form (GeP), as shown by NMR studies and X-ray diffraction. Reactions of (GeP) with CdPh afford [K(crypt-222)][Cd(GeP)], containing an unprecedented ternary cluster anion with a triangular Cd moiety.

Crystalline Superlattices of Nanoscopic CdS Molecular Clusters: An X-ray Crystallography and Cd SSNMR Spectroscopy Study.

Systematic Cd solid-state (SS) NMR experiments were performed to correlate X-ray crystallographic data with SSNMR parameters for a set of CdS-based materials, varying from molecular crystals of small complexes [Cd(SPh)] and [Cd(SPh)] to superlattices of large monodisperse clusters [CdS(SPh)(dmf)] and 1.9 nm CdS. Methodical data analysis allowed for assigning individual resonances or resonance groups to particular types of cadmium sites residing in different chemical and/or crystallographic environments.

A N-Heterocyclic Carbene-Stabilized Coinage Metal-Chalcogenide Framework with Tunable Optical Properties.

A new class of coinage-metal chalcogenide compounds [AuM(μ-E)(IPr)] (M = Ag, Au; E = S, Se, Te) has been synthesized from the combination of N-heterocyclic carbene-ligated gold(I) trimethylsilylchalcogenolates [(IPr)AuESiMe] and ligand-supported metal acetates. Phosphorescence is observed from these clusters in glassy 2-methyltetrahydrofuran and in the solid state at 77 K, with emission energies that depend on the selection of metal/chalcogen ion composition. The ability to tune the emission is attributed to electronic transitions of mixed ligand-to-metal-metal-charge-transfer (IPr → AuM) and interligand (IPr → E) phosphorescence character, as revealed by time-dependent density functional theory computations.

Luminescent CdSe Superstructures: A Nanocluster Superlattice and a Nanoporous Crystal.

Superstructures, combining nanoscopic constituents into micrometer-size assemblies, have a great potential for utilization of the size-dependent quantum-confinement properties in multifunctional electronic and optoelectronic devices. Two diverse superstructures of nanoscopic CdSe were prepared using solvothermal conversion of the same cadmium selenophenolate precursor (MeN)[Cd(SePh)]: the first is a superlattice of monodisperse [CdSe(SePh)(dmf)] nanoclusters; the second is a unique porous CdSe crystal. Nanoclusters were crystallized as cubic crystals (≤0.

A Controlled Route to a Luminescent 3 d -5 d Sulfido Cluster Containing Unique AuCu (μ -S) Motifs.

The first examples of gold(I) trimethylsilylchalcogenolate complexes were synthesized and their reactivity showcased in the preparation of a novel gold-copper-sulfur cluster [Au Cu S (dppm) ] (dppm=bis(diphenylphosphino)methane). The unprecedented structural chemistry of this compound gives rise to interesting optoelectronic properties, including long-lived orange luminescence in the solid state. Through time-dependent density functional theory calculations, this emission is shown to originate from ligand-to-metal charge transfer facilitated by Au⋅⋅⋅Cu metallophilic bonding.

Facile Preparation of Wurtzite CuInE (E = S, Se) Nanoparticles Under Solvothermal Conditions.

In this work, the synthesis of nanoscale CuInS and CuInSe was developed using molecular precursors of the type [(PhP)CuIn(ER)] (E = S, Se) and solvothermal reactions. Various conditions were investigated including the use of different precursors, reaction temperatures, reaction times and the addition of a secondary chalcogen source to mixtures. After optimizing conditions, nanoparticles of CuInS and CuInSe were isolated with controlled sizes in the range of 2-5 nm (wurtzite structure), which ultimately tuned the band gap energies of the materials.

Stable -ESiMe3 Complexes of Cu(I) and Ag(I) (E=S, Se) with NHCs: Synthons in Ternary Nanocluster Assembly.

As a part of efforts to prepare new "metallachalcogenolate" precursors and develop their chemistry for the formation of ternary mixed-metal chalcogenide nanoclusters, two sets of thermally stable, N-heterocyclic carbene metal-chalcogenolate complexes of the general formula [(IPr)Ag-ESiMe3] (IPr=1,3-bis(2,6-diisopropylphenyl)imidazolin-2-ylidene; E=S, 1; Se, 2) and [(iPr2-bimy)Cu-ESiMe3]2 (iPr2-bimy=1,3-diisopropylbenzimidazolin-2-ylidene; E=S, 4; Se, 5) are reported. These are prepared from the reaction between the corresponding carbene metal acetate, [(IPr)AgOAc] and [(iPr-bimy)CuOAc] respectively, and E(SiMe3 )2 at low temperature. The reaction of [(IPr)Ag-ESiMe3] 1 with mercury(II) acetate affords the heterometallic complex [{(IPr)AgS}2Hg] 3 containing two (IPr)Ag-S(-) fragments bonded to a central Hg(II), representing a mixed mercury-silver sulfide complex.

Enhanced thermal stability of Cu-silylphosphido complexes via NHC ligation.

The facile preparation and structural characterization of [M6{P(SiMe3)2}6] (M = Ag, Cu) is reported. These complexes show limited stability towards solvent loss at ambient temperature; however, N-heterocyclic carbene (NHC) ligands were used to synthesize more thermally stable metal-silylphosphido compounds. 1,3-Di-isopropylbenzimidazole-2-ylidene ((i)Pr2-bimy) and 1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene (IPr) are found to be excellent ligands to stabilize silylphosphido-copper compounds that show higher stability when compared to [Cu6{P(SiMe3)2}6].

Simple but effective: thermally stable Cu-ESiMe3via NHC ligation.

A series of thermally stable N-heterocyclic copper-chalcogenolate complexes of the general formula [(IPr)Cu-ESiMe3] (IPr = 1,3-bis(2,6-diisopropylphenyl)imidazolin-2-ylidene; E = S, Se, Te) have been prepared from [(IPr)CuOAc] and E(SiMe3)2 at low temperature. The reaction of [(IPr)Cu-SSiMe3] with mercuric(II) acetate affords the heterometallic [{(IPr)CuS}2Hg] complex containing two (IPr)Cu-S(-) fragments to a central Hg(II).

Polydentate chalcogen reagents for the facile preparation of Pd2 and Pd4 complexes.

The silylated organochalcogen reagents 1,2-(Me3SiSCH2)2C6H4, and 1,2-(Me3SiSeCH2)2C6H4, were prepared from the corresponding organobromides and lithium trimethylsilanechalcogenolate Li[ESiMe3] (E = S, Se). They have been characterized by multinuclear NMR spectroscopy ((1)H, (13)C, (77)Se) and electrospray ionization mass spectrometry. and react under mild conditions with (1,3-bis(diphenylphosphino)propane)palladium(ii) chloride, [PdCl2(dppp)], to provide the dinuclear organochalcogenolate-bridged complexes [(dppp)2Pd2-μ-κ(2)S-{1,2-(SCH2)2C6H4}]X2, []X2 and [(dppp)2Pd2-μ-κ(2)Se-{1,2-(SeCH2)2C6H4}]X2, []X2 (X = Cl, Br) in good yield, respectively.

A functionalized Ag₂S molecular architecture: facile assembly of the atomically precise ferrocene-decorated nanocluster [Ag₇₄S₁₉(dppp)₆(fc(C{O}OCH₂CH₂S)₂)₁₈].

A ferrocene-based dithiol 1,1'-[fc(C{O}OCH2CH2SH)2] has been prepared and treated with a Ag(I) salt to form the stable dithiolate compound [fc(C{O}OCH2CH2SAg)2]n (fc=[Fe(η(5)-C5H4)2]). This is used as a reagent for the preparation of the nanocluster [Ag74S19(dppp)6(fc(C{O}OCH2CH2S)2)18] which was obtained in good yield (dppp=1,3-bis(diphenylphosphino)propane).

N-Heterocyclic carbene stabilized Ag-P nanoclusters.

The N-heterocyclic carbene (NHC) 1,3-di-isopropylbenzimidazole-2-ylidene ((i)Pr2-bimy) is found to be an excellent ligand for the stabilization of silver-phosphorus polynuclear complexes. The straightforward preparation and characterization of the clusters [Ag12(PSiMe3)6((i)Pr2-bimy)6] (1) and [Ag26P2(PSiMe3)10((i)Pr2-bimy)8] (2) are described, representing the first examples of such structurally characterized, higher nuclearity complexes obtained using this class of ligands.

New polydentate trimethylsilyl chalcogenide reagents for the assembly of polyferrocenyl architectures.

A series of polychalcogenotrimethylsilane complexes Ar(CH2ESiMe3)n, (Ar = aryl; E = S, Se; n = 2, 3, and 4) can be prepared from the corresponding polyorganobromide and M[ESiMe3] (M = Na, Li). These represent the first examples of the incorporation of such a large number of reactive -ESiMe3 moieties onto an organic molecular framework. They are shown to be convenient reagents for the preparation of the polyferrocenylseleno- and thioesters from ferrocenoyl chloride.

N-heterocyclic carbenes as effective ligands for the preparation of stabilized copper- and silver-t-butylthiolate clusters.

The ligation of N-heterocyclic carbenes (NHCs) to [CuS(t)Bu] and [AgS(t)Bu] was developed as an alternative to PR3 ligands as solubilizing reagents for these coordination polymers in order to form polynuclear copper and silver t-butylthiolate clusters. 1,3-Di-isopropylbenzimidazol-2-ylidene ((i)Pr2-bimy) and 1,3-di-isopropyl-4,5-dimethylimidazol-2-ylidene ((i)Pr2-mimy) were ligated to [CuS(t)Bu] and [AgS(t)Bu] forming [Cu4(S(t)Bu)4((i)Pr2-bimy)2] 1, [Cu4(S(t)Bu)4((i)Pr2-mimy)2] 2, [Ag4(S(t)Bu)4((i)Pr2-bimy)2] 5 and [Ag5(S(t)Bu)6][Ag((i)Pr2-mimy)2] 6. For comparison, the trialkyl phosphines P(n)Pr3 and P(i)Pr3 were also used to solubilize [AgS(t)Bu] and [CuS(t)Bu] to form copper and silver t-butylthiolate clusters.

Copper chalcogenide clusters stabilized with ferrocene-based diphosphine ligands.

The redox-active diphosphine ligand 1,1'-bis(diphenylphosphino)ferrocene (dppf) has been used to stabilize the copper(I) chalcogenide clusters [Cu12(μ4-S)6(μ-dppf)4] (1), [Cu8(μ4-Se)4(μ-dppf)3] (2), [Cu4(μ4-Te)(μ4-η(2)-Te2)(μ-dppf)2] (3), and [Cu12(μ5-Te)4(μ8-η(2)-Te2)2(μ-dppf)4] (4), prepared by the reaction of the copper(I) acetate coordination complex (dppf)CuOAc (5) with 0.5 equiv of E(SiMe3)2 (E = S, Se, Te). Single-crystal X-ray analyses of complexes 1-4 confirm the presence of {Cu(2x)E(x)} cores stabilized by dppf ligands on their surfaces, where the bidentate ligands adopt bridging coordination modes.

Nanocluster isotope distributions measured by electrospray time-of-flight mass spectrometry.

Electrospray ionization (ESI) mass spectrometry (MS) is a widely used tool for the characterization of organometallic nanoclusters. By matching experimental mass spectra with calculated isotope distributions it is possible to determine the elemental composition of these analytes. In this work we conduct ESI-MS investigations on M(14)E(13)Cl(2)(tmeda)(6) nanoclusters, where M is a transition metal, E represents a chalcogen, and tmeda is N,N,N',N'-tetramethyl-ethylenediamine.

Zinc chalcogenolate complexes as precursors to ZnE and Mn/ZnE (E = S, Se) clusters.

The ternary clusters (tmeda)(6)Zn(14-x)Mn(x)S(13)Cl(2) (1a-d) and (tmeda)(6)Zn(14-x)Mn(x)Se(13)Cl(2) (2a-d), (tmeda = N,N,N',N'-tetramethylethylenediamine; x ≈ 2-8) and the binary clusters (tmeda)(6)Zn(14)E(13)Cl(2) (E = S, 3; Se, 4;) have been isolated by reacting (tmeda)Zn(ESiMe(3))(2) with Mn(II) and Zn(II) salts. Single crystal X-ray analysis of the complexes confirms the presence of the six "(tmeda)ZnE(2)" units as capping ligands that stabilize the clusters, and distorted tetrahedral geometry around the metal centers. Mn(II) is incorporated into the ZnE framework by substitution of Zn(II) ions in the cluster.