Diselenophosphate‐Induced Conversion of an Achiral [Cu20H11{S2P(OiPr)2}9] into a Chiral [Cu20H11{Se2P(OiPr)2}9] Polyhydrido Nanocluster

A polyhydrido copper nanocluster, [Cu₂₀H₁₁{Se₂P(OiPr)₂}₉] ( 2_H ), which exhibits an intrinsically chiral inorganic core of C₃ symmetry, was synthesized from achiral [Cu₂₀H₁₁{S₂P(OiPr)₂}₉] ( 1_H ) of C_3h symmetry by a ligand‐exchange method. The structure has a distorted cuboctahedral Cu₁₃ core, two triangular faces of which are capped along the C₃ axis, one by a Cu₆ cupola and the other by a single Cu atom. The Cu₂₀ framework is further stabilized by 9 diselenophosphate and 11 hydride ligands. The number of hydride, phosphorus, and selenium resonances and their splitting patterns in multinuclear NMR spectra of 2_H indicate that the chiral Cu₂₀H₁₁ core retains its C₃ symmetry in solution. The 11 hydride ligands were located by neutron diffraction experiments and shown to be capping μ₃‐H and interstitial μ₅‐H ligands (in square‐pyramidal and trigonal‐bipyramidal cavities), as supported by DFT calculations on [Cu₂₀H₁₁(Se₂PH₂)₉] ( 2_H′ ) as a simplified model.     

Polyhydrido Copper Nanoclusters with a Hollow Icosahedral Core: [Cu30H18{E2P(OR)2}12] (E=S or Se; R=nPr,iPr or iBu)

Although atomically precise polyhydrido copper nanoclusters are of prime interest for a variety of applications, they have so far remained scarce. Herein, this work describes the synthesis of a dithiophosphate-protected copper(I) hydride-rich nanocluster (NC), [Cu₃₀H₁₈{S₂P(OnPr)₂}₁₂] ( 1_H ), fully characterized by various spectroscopic methods and single-crystal X-ray diffraction. The X-ray structure of 1_H reveals an unprecedented central Cu₁₂ hollow icosahedron. Six faces of this icosahedron are capped by Cu₃ triangles, the whole Cu₃₀ core being wrapped by twelve dithiophosphate ligands and the whole cluster has ideal S₆ symmetry. The locations of the 18 hydrides in 1_H were ascertained by a single-crystal neutron diffraction study. They are composed of three types: capping μ₃-H, interstitial μ₄-H (seesaw) and μ₅-H ligands (square pyramidal), in good agreement with the DFT simulations. The numbers of hydrides and ligand resonances in the ¹H NMR spectrum of 1_H are in line with their coordination environment in the solid state, retaining the S₆ symmetry in solution. Furthermore, two new Se-protected polyhydrido copper nanoclusters, [Cu₃₀H₁₈{Se₂P(OR)₂}₁₂] ( 2_H : R=iPr 3_H : R=iBu) were synthesized from their sulfur relative 1_H via ligand displacement reaction and their X-ray structures feature the exceptional case where both the NC shape and size are fully conserved during the course of ligand exchange. DFT and TD-DFT calculations allow understanding the bonding and optical properties of clusters 1_H – 3_H . In addition, the reaction of 1_H with [Pd(PPh₃)₂Cl₂] in the presence of terminal alkynes led to the formation of new bimetallic Cu−Pd alloy clusters [PdCu₁₄H₂{S₂P(OnPr)₂}₆(C≡CR)₆] ( 4 : R=Ph; 5 : R = C₆H₄F).     

Eight‐Electron Silver and Mixed Gold/Silver Nanoclusters Stabilized by Selenium Donor Ligands

The first atomically and structurally precise silver‐nanoclusters stabilized by Se‐donor ligands, [Ag₂₀{Se₂P(OⁱPr)₂}₁₂] ( 3 ) and [Ag₂₁{Se₂P(OEt)₂}₁₂]⁺( 4 ), were isolated by ligand replacement reaction of [Ag₂₀{S₂P(Oⁱ Pr)₂}₁₂] ( 1 ) and [Ag₂₁{S₂P(Oⁱ Pr)₂}₁₂]⁺ ( 2 ), respectively. Furthermore, doping reactions of 4 with Au(PPh₃)Cl resulted in the formation of [AuAg₂₀{Se₂P(OEt)₂}₁₂]⁺ ( 5 ). Structures of 3 , 4 , and 5 were determined by single‐crystal X‐ray diffraction. The anatomy of cluster 3 with an Ag₂₀ core having C ₃ symmetry is very similar to that of its dithiophosphate analogue 1 . Clusters 4 and 5 exhibit an Ag₂₁ and Au@Ag₂₀ core of O_h symmetry composed of eight silver capping atoms in a cubic arrangement and encapsulating an Ag₁₃ and Au@Ag₁₂ centered icosahedron, respectively. Both ligand exchange and heteroatom doping result in significant changes in optical and emissive properties for chalcogen‐passivated silver nanoparticles, which have been theoretically confirmed as 8‐electron superatoms.     

Hydride-containing 2-Electron Pd/Cu Superatoms as Catalysts for Efficient Electrochemical Hydrogen Evolution

The first hydride-containing 2-electron palladium/copper alloys, [PdHCu₁₁{S₂P(OⁱPr)₂}₆(C≡CPh)₄] ( PdHCu₁₁ ) and [PdHCu₁₂{S₂P(OⁱPr)₂}₅{S₂PO(OⁱPr)} (C≡CPh)₄] ( PdHCu₁₂ ), are synthesized from the reaction of [PdH₂Cu₁₄{S₂P(OⁱPr)₂}₆(C≡CPh)₆] ( PdH₂Cu₁₄ ) with trifluoroacetic acid (TFA). X-ray diffraction reveals that the PdHCu₁₁ and PdHCu₁₂ kernels consist of a central PdH unit encapsulated within a vertex-missing Cu₁₁ cuboctahedron and complete Cu₁₂ cuboctahedron, respectively. DFT calculations indicate that both PdHCu₁₁ and PdHCu₁₂ can be considered as axially-distorted 2-electron superatoms. PdHCu₁₁ shows excellent HER activity, unprecedented within metal nanoclusters, with an onset potential of −0.05 V (at 10 mA cm⁻²), a Tafel slope of 40 mV dec⁻¹, and consistent HER activity during 1000 cycles in 0.5 M H₂SO₄. Our study suggests that the accessible central Pd site is the key to HER activity and may provide guidelines for correlating catalyst structures and HER activity.     

Synthesis of Bimetallic Copper‐Rich Nanoclusters Encapsulating a Linear Palladium Dihydride Unit

The structurally precise Cu‐rich hydride nanoclusters [PdCu₁₄H₂(dtc/dtp)₆(C≡CPh)₆] (dtc: di‐butyldithiocarbamate ( 1 ); dtp: di‐isopropyl dithiophosphate ( 2 )) were synthesized from the reaction of polyhydrido copper clusters [Cu₂₈H₁₅(S₂CNⁿBu₂)₁₂]⁺ or [Cu₂₀H₁₁{S₂P(OⁱPr)₂}₉] with phenyl acetylene in the presence of Pd(PPh₃)₂Cl₂. Their structures and compositions were determined by single‐crystal X‐ray diffraction and the results supported by ESI‐mass spectrometry. Hydride positions in 1 were confirmed by single‐crystal neutron diffraction. Each hydride is connected to one Pd⁰ and four Cu^I atoms in slightly distorted trigonalbipyramidal geometry. The anatomies of clusters 1 and 2 are very similar and DFT calculations allow rationalizing the interactions between the encapsulated [PdH₂]^2? unit and its Cu₁₄ bicapped icosahedral cage. As a result, Pd has the highest coordination number (14) so far recorded.     

Octanuclear Cu(I)‐dithiophosphates: An Efficient Catalyst System for N‐Arylation of Azoles,Amines, and Amides

The formation of a C‐N bond via the cross‐couplings of aryl iodides with azoles, aryl amine, and amides can be successfully achieved in decent yield by the utilization of both [Cu ₈(H){S₂P(OⁱPr)₂}₆]⁺ and [Cu₈{S₂P(OEt)₂}₆]²⁺ as the pre‐catalysts.     

[Ag21{S2P(OiPr)2}12]+: An Eight‐Electron Superatom

A novel discrete [Ag₂₁{S₂P(OiPr)₂}₁₂](PF₆) nanocluster has been synthesized and characterized by single‐crystal X‐ray diffraction and also NMR spectroscopy (¹H, ³¹P), ESI mass spectrometry, and other analytic techniques (XPS, EDS, UV/Vis spectroscopy). The Ag₂₁ skeleton has an unprecedented silver‐centered icosahedron that is capped by eight additional metal atoms. The whole framework is protected by twelve dithiophosphate ligands. According to the spherical Jellium model, the stability of monocationic nanocluster can be described by an 8‐electron superatom with 1S² 1P⁶ configuration, as confirmed by DFT calculations.     

[Cu32(H)20{S2P(OiPr)2}12]: The Largest Number of Hydrides Recorded in a Molecular Nanocluster by Neutron Diffraction

An air‐ and moisture‐stable nanoscale polyhydrido copper cluster [Cu₃₂(H)₂₀{S₂P(OiPr)₂}₁₂] ( 1_H ) was synthesized and structurally characterized. The molecular structure of 1_H exhibits a hexacapped pseudo‐rhombohedral core of 14 Cu atoms sandwiched between two nestlike triangular cupola fragments of (2×9) Cu atoms in an elongated triangular gyrobicupola polyhedron. The discrete Cu₃₂ cluster is stabilized by 12 dithiophosphate ligands and a record number of 20 hydride ligands, which were found by high‐resolution neutron diffraction to exhibit tri‐, tetra‐, and pentacoordinated hydrides in capping and interstitial modes. This result was further supported by a density functional theory investigation on the simplified model [Cu₃₂(H)₂₀(S₂PH₂)₁₂].     

Cobalt(II) Complexes with N‐Thioacylamidophosphates and 2,2′‐Bipyridyl and 1,10‐Phenathroline. Crystal Structures,Solution 1H NMR Spectral and Magnetic Properties

Structure and magnetic properties of N‐diisopropoxyphosphorylthiobenzamide PhC(S)‐N(H)‐P(O)(OiPr)₂ ( HL^I ) and N‐diisopropoxyphosphoryl‐N′‐phenylthiocarbamide PhN(H)‐C(S)‐N(H)‐P(O)(OiPr)₂ ( HL^II ) complexes with the Co^II cation of formulas [Co{PhC(S)‐N‐P(O)(OiPr)₂}₂] ( 1 ), [Co{PhN(H)‐C(S)‐N‐P(O)(OiPr)₂}₂] ( 2 ), [Co{PhC(S)‐N(H)‐P(O)(OiPr)₂}₂{PhC(S)‐N‐P(O)(OiPr)₂}₂] ( 1a ) and [Co{PhC(S)‐N‐P(O)(OiPr)₂}₂}(2,2′‐bipy)] ( 3 ), [Co{PhC(S)‐N‐P(O)(OiPr)₂}₂(1,10‐phen)] ( 4 ), [Co{PhN(H)‐C(S)‐N‐P(O)(OiPr)₂}₂(2,2′‐bipy)] ( 5 ), [Co{PhN(H)‐C(S)‐N‐P(O)(OiPr)₂}₂(1,10‐phen)] ( 6 ) were investigated. Paramagnetic shifts in the ¹H NMR spectrum were observed for high‐spin Co^II complexes with HL^I,II , incorporating the S‐C‐N‐P‐O chelate moiety and two aromatic chelate ligands. Investigation of the thermal dependence of the magnetic susceptibility has shown that the extended materials 1‐2 and 6 show ferromagnetic exchange between distorted tetrahedral ( 1 , 2 ) or octahedral ( 1a , 6 ) metal atoms whereas 3 and 5 show antiferromagnetic properties. Compound 4 behaves as a spin‐canted ferromagnet, an antiferromagnetic ordering taking place below a critical temperature, T_c = 115 K. Complexes 1 and 1a were investigated by single crystal X‐ray diffraction. The cobalt(II) atom in complex 1 resides a distorted tetrahedral O₂S₂ environment formed by the C=S sulfur atoms and the P=O oxygen atoms of two deprotonated ligands. Complex 1a has a tetragonal‐bipyramidal structure, Co(O^ax)₂(O^eq)₂(S^eq)₂, and two neutral ligand molecules are coordinated in the axial positions through the oxygen atoms of the P=O groups. The base of the bipyramid is formed by two anionic ligands in the typical 1,5‐O,S coordination mode. The ligands are in a trans configuration.     

A New Synthetic Methodology in the Preparation of Bimetallic Chalcogenide Clusters via Cluster-to-Cluster Transformations

A decanuclear silver chalcogenide cluster, [Ag₁₀(Se){Se₂P(OⁱPr)₂}₈] (2) was isolated from a hydride-encapsulated silver diisopropyl diselenophosphates, [Ag₇(H){Se₂P(OⁱPr)₂}₆], under thermal condition. The time-dependent NMR spectroscopy showed that 2 was generated at the first three hours and the hydrido silver cluster was completely consumed after thirty-six hours. This method illustrated as cluster-to-cluster transformations can be applied to prepare selenide-centered decanuclear bimetallic clusters, [Cu_xAg_10-x(Se){Se₂P(OⁱPr)₂}₈] (x = 0–7, 3), via heating [Cu_xAg_7−x(H){Se₂P(OⁱPr)₂}₆] (x = 1–6) at 60 °C. Compositions of 3 were accurately confirmed by the ESI mass spectrometry. While the crystal 2 revealed two un-identical [Ag₁₀(Se){Se₂P(OⁱPr)₂}₈] structures in the asymmetric unit, a co-crystal of [Cu₃Ag₇(Se){Se₂P(OⁱPr)₂}₈]_0.6[Cu₄Ag₆(Se){Se₂P(OⁱPr)₂}₈]_0.4 ([3a]_0.6[3b]_0.4) was eventually characterized by single-crystal X-ray diffraction. Even though compositions of 2, [3a]_0.6[3b]_0.4 and the previous published [Ag₁₀(Se){Se₂P(OEt)₂}₈] (1) are quite similar (10 metals, 1 Se²⁻, 8 ligands), their metal core arrangements are completely different. These results show that different synthetic methods by using different starting reagents can affect the structure of the resulting products, leading to polymorphism.     

Seed free high yield gold nanorods synthesis from single precursor gold(I) dithiophosphate complex

In this work, we demonstrate a simple, one pot and seed free synthetic route for the formation of gold nanorods (Au NRs) via thermal decomposition of gold(I) dithiophosphate {[Au₂{S₂P(OⁱPr)₂}₂]_n,} 1 complex as a molecular precursor in presence of 4′‐amino‐biphenyl‐4‐carboxylic molecule. Here [Au₂{S₂P(OⁱPr)₂}₂]_n, complex functioned as gold (Au) source and 4′‐amino‐biphenyl‐4‐carboxylic molecule stabilized gold (Au) nanorods (NRs) through the unidirectional coating of Au surface during its growth in the reaction medium.     

Phosphor-1,1-Diselenolato Metal Complexes of Group 11 and 12

Abstract

Several copper and silver clusters containing diselenophosphate ligands such as tetranuclear [Cu{Se₂P(OR)₂}]₄, hexanuclear [Ag{Se₂P(OR)₂}]₆, octanuclear [Cu₈(μ₈-Se)}Se₂P(OR)₂}₆], [Ag₈(μ₈-Se)}Se₂P(OR)₂}₆], [Cu₈(μ₈-X)}Se₂P(OR)₂}₆](PF₆), [Ag₈(μ₈-X)}Se₂P(OR)₂}₆](PF₆), decanuclear [Ag₁₀(μ₁₀-Se)}Se₂P(OR)₂}₈], undecanuclear [Cu₁₁(μ₉-Se)(μ₃-X)₃}Se₂P(OR)₂}₆], [Ag₁₁(μ₉-Se)(μ₃-X)₃}Se₂P(OR)₂}₆], and dodecanuclear [Cu₁₂(P₂Se₆)}Se₂P(OR)₂}₈] have been isolated. All these clusters were well characterized in the solid-state and solution phase by elemental analysis, positive FAB mass spectrometry, multinuclear NMR (¹H, ³¹P, and ⁷⁷Se), and single crystal X-ray diffraction. In addition, tetranuclear zinc clusters [Zn₄(μ₄-Se){Se₂P(OPr)₂}₆], and [Zn₄(μ₄-O){Se₂P(OR)₂}₆] (R = Et, ⁱPr) also are synthesized and characterized. Solution studies of both [M{Se₂P(OEt)₂}₂]∞ and [M₂{Se₂P(OⁱPr)₂}₄] (M = Zn, Cd) which display a monomer-dimer equilibrium in solution were performed by VT ³¹P NMR in CD₂Cl₂.     

Bis­[bis(N,N‐diethyl‐1,1‐di­seleno­car­bam­ato)copper(II)], [Cu(Se2CNEt2)2]2

The title centrosymmetric Cu^II binuclear complex, bis(μ‐N,N‐diethyl‐1,1‐di­seleno­carbamato‐Se,Se′:Se)­bis­[(N,N‐diethyl‐1,1‐di­seleno­carbamato‐Se,Se′)copper(II)], [Cu(Se₂CNEt₂)₂]₂ or [Cu₂(C₅H₁₀NSe₂)₄], is built from two symmetry‐related [Cu{Se₂CN(Et)₂}₂] units by pairs of Cu—Se bonds. The coordination geometry at the unique Cu atom is distorted square pyramidal, with Cu—Se distances in the range 2.4091 (11)—2.9095 (10) Å.     

Different Metal Aggregation in Copper Acetate Chain Coordination Polymers with Dipyridyl Tethers Bearing Hydrogen Bonding Capable Functional Groups

Hydrothermal synthesis has afforded a pair of divalent copper acetate coordination polymers containing either 4, 4′‐dipyridylamine (dpa) or 4‐pyridylisonicotinamide (4‐pina), both of which hydrogen‐bonding capable central functional groups. X‐ray crystallography revealed that both exhibit a 1D chain dimensionality. Use of the kinked tethering ligand dpa produced [Cu(OAc)₂(dpa)]_n ( 1 ), which possesses a simple chain based on dpa linkage of isolated copper ions. On the other hand, employing the straighter amide ligand 4‐pina generated {[Cu(OAc)₂(4‐pina)] · 0.5H₂O}_n ( 2 ), which exhibits {Cu₂O₂} rhomboid dimers formed through bridging acetate ligands. Weak antiferromagnetic coupling [g = 1.984(3), J = –3.2(3) cm^–1] was observed within the axial‐equatorial bridged {Cu₂O₂} dimers in 2 , with possible ferrimagnetism due to spin canting below 11 K.     

An Ultrastable,Small {Ag7}5+ Nanocluster within a Triangular Hollow Polyoxometalate Framework

Small Ag_n nanoclusters (n<10) have been emerging as promising materials as sensing, biolabeling, and catalysis because of their unique electronic states and optical properties. However, studying synthesis, structure determination, and exploration of their properties remain major challenges as a result of the low stability of small Ag nanoclusters. Herein, we synthesized an atomically precise face‐centered‐cubic‐type small {Ag₇}⁵⁺ nanocluster supported by a novel triangular hollow polyoxometalate (POM) framework [Si₃W₂₇O₉₆]^18?. The cluster showed unique {Ag₇}⁵⁺‐to‐POM charge transfer bands in both visible and UV light regions. Furthermore, this small {Ag₇}⁵⁺ nanocluster exhibited an unprecedented ultrastability in solution, despite having exposed Ag sites that can be accessed by small molecules, such as O₂, water, and solvents.     

Chlorobis[N′‐ethoxycarbonyl‐N‐(4‐methylphenyl)thiourea‐κS]copper(I)

The title complex, chloro­bis{ethyl N‐[(4‐methyl­anilino)­thio­carbonyl]­carbamate‐κS}copper(I), [CuCl(C₁₁H₁₄N₂O₂S)₂], was synthesized by the reaction of cupric chloride with the corresponding thio­urea derivative. The complex has imposed crystallographic m symmetry and the Cu^I coordination environment is trigonal planar, formed by two S atoms and one Cl atom. The formation of intramolecular hydrogen bonds promotes the stability of the complex.     

The first square‐planar copper(II) 1:2 complex with differently coordinated 2‐hydroxybenzaldehyde 4‐allylthiosemicarbazone ligands

The title compound, [(Z)‐4‐allyl‐2‐(2‐hydroxybenzylidene)thiosemicarbazide‐κS][(E)‐4‐allyl‐1‐(2‐oxidobenzylidene)thiosemicarbazidato‐κ³O,N¹,S]copper(II) monohydrate, [Cu(C₁₁H₁₁N₃OS)(C₁₁H₁₃N₃OS)]·H₂O, crystallized as a rotational twin in the monoclinic crystal system (space group Cc) with two formula unit (Z′ = 2) in the asymmetric unit, one of which contains an allyl substituent disordered over two positions. The Cu^II atom exhibits a distorted square‐planar geometry involving two differently coordinated thiosemicarbazone ligands. One ligand is bonded to the Cu^II atom in a tridentate manner via the phenolate O, azomethine N and thioamide S atoms, while the other coordinates in a monodentate manner via the S atom only. The complex is stabilized by an intramolecular hydrogen bond, which creates a six‐membered pseudo‐chelate metalla‐ring. The structure analysis indicates the presence of the E isomer for the tridentate ligand and the Z isomer for the monodentate ligand. The crystal structure contains a three‐dimensional network built from intermolecular O—H...O, N—H...O, O—H...N and N—H...S hydrogen bonds.     

Dioxygen Activation by a Macrocyclic Copper Complex Leads to a Cu2O2 Core with Unexpected Structure and Reactivity

We report the Cu^I/O₂ chemistry of complexes derived from the macrocylic ligands 14‐TMC (1,4,8,11‐tetramethyl‐1,4,8,11‐tetraazacyclotetradecane) and 12‐TMC (1,4,7,10‐tetramethyl‐1,4,7,10‐tetraazacyclododecane). While [(14‐TMC)Cu^I]⁺ is unreactive towards dioxygen, the smaller analog [(12‐TMC)Cu^I(CH₃CN)]⁺ reacts with O₂ to give a side‐on bound peroxo‐dicopper(II) species (^SP), confirmed by spectroscopic and computational methods. Intriguingly, 12‐TMC as a N4 donor ligand generates ^SP species, thus in contrast with the previous observation that such species are generated by N2 and N3 ligands. In addition, the reactivity of this macrocyclic side‐on peroxo‐dicopper(II) differs from typical ^SP species, because it reacts only with acid to release H₂O₂, in contrast with the classic reactivity of Cu₂O₂ cores. Kinetics and computations are consistent with a protonation mechanism whereby the TMC acts as a hemilabile ligand and shuttles H⁺ to an isomerized peroxo core.