Chinese Puzzle Molecule: A 15 Hydride, 28 Copper Atom Nanoball

The syntheses of the first rhombicuboctahedral copper polyhydride complexes [Cu₂₈(H)₁₅(S₂CNR)₁₂]PF₆ (NR=NⁿPr₂ or aza‐15‐crown‐5) are reported. These complexes were analyzed by single‐crystal X‐ray and one by neutron diffraction. The core of each copper hydride nanoparticle comprises one central interstitial hydride and eight outer‐triangular‐face‐capping hydrides. A further six face‐truncating hydrides form an unprecedented bridge between the inner and outer copper atom arrays. The irregular inner Cu₄ tetrahedron is encapsulated within the Cu₂₄ rhombicuboctahedral cage, which is further enclosed by an array of twelve dithiocarbamate ligands that subtends the truncated octahedron of 24 sulfur atoms, which is concentric with the Cu₂₄ rhombicuboctahedron and Cu₄ tetrahedron about the innermost hydride. For these compounds, an intriguing, albeit limited, H₂ evolution was observed at room temperature, which is accompanied by formation of the known ion [Cu₈(H)(S₂CNR)₆]⁺ upon exposure of solutions to sunlight, under mild thermolytic conditions, and on reaction with weak (or strong) acids.     

Facially Dispersed Polyhydride Cu9 and Cu16 Clusters Comprising Apex‐Truncated Supertetrahedral and Square‐Face‐Capped Cuboctahedral Copper Frameworks

By using a linear tetraphosphine, meso‐bis[(diphenylphosphinomethyl)phenylphosphino]methane (dpmppm), nona‐ and hexadecanuclear copper hydride clusters, [Cu₉H₇(μ‐dpmppm)₃]X₂ (X=Cl ( 1 a ), Br ( 1 b ), I ( 1 c ), PF₆ ( 1 d )) and [Cu₁₆H₁₄(μ‐dpmppm)₄]X₂ (X₂=I₂ ( 2 c ), (4/3) PF₆?(2/3) OH ( 2 d )) were synthesized and characterized. They form copper‐hydride cages of apex‐truncated supertetrahedral {Cu₉H₇}²⁺ and square‐face‐capped cuboctahedral {Cu₁₆H₁₄}²⁺ structures. The hydride positions were estimated by DFT calculations to be facially dispersed around the copper frameworks. A kinetically controlled synthesis gave an unsymmetrical Cu₈H₆ cluster, [Cu₈H₆(μ‐dpmppm)₃]²⁺ ( 3 ), which readily reacted with CO₂ to afford linear Cu₄ complexes with formate bridges, leading to an unprecedented hydrogenation of CO₂ into formate catalyzed by {Cu₄(μ‐dpmppm)₂} platform. The results demonstrate that new motifs of copper hydride clusters could be established by the tetraphosphine ligands, and the structures influence their reactivity.     

Synthesis of Two‐Electron Bimetallic Cu–Ag and Cu–Au Clusters by using [Cu13(S2CNnBu2)6(C≡CPh)4]+ as a Template

Atomically precise Cu‐rich bimetallic superatom clusters have been synthesized by adopting a galvanic exchange strategy. [Cu@Cu₁₂(S₂CNⁿBu₂)₆(C≡CPh)₄][CuCl₂] ( 1 ) was used as a template to generate compositionally uniform clusters [M@Cu₁₂(S₂CNⁿBu₂)₆ (C≡CPh)₄][CuCl₂], where M=Ag ( 2 ), Au ( 3 ). Structures of 1 , 2 and 3 were determined by single crystal X‐ray diffraction and the results were supported by ESI‐MS. The anatomies of clusters 1 – 3 are very similar, with a centred cuboctahedral cationic core that is surrounded by six di‐butyldithiocarbamate (dtc) and four phenylacetylide ligands. The doped Ag and Au atoms were found to preferentially occupy the centre of the 13‐atom cuboctahedral core. Experimental and theoretical analyses of the synthesized clusters revealed that both Ag and Au doping result in significant changes in cluster stability, optical characteristics and enhancement in luminescence properties.     

Three Heterometallic Mo–M′ Cubane-Like Tetranuclear Cluster Compounds (M′=Cu, Pb, Sb): Synthesis, Structure and Third-Order NLO Property

Three new heterometallic tetranuclear cluster compounds with a [Mo₃YS₃M] cubane-like cluster core (M=Cu, Pb, Sb; Y=O, S), [Mo₃OS₃(CuI)(-OAc)₂(dtp)₂(DMF)] (1), (dtp=S₂P(OC₂H₅)^– ₂), [Mo₃OS₃(PbI₃)(dtc)₃(py)₃] (2) (dtc=S₂CN(C₂H₅)^– ₂), [Mo₃S₄(SbI₃)(dtcpyr)₄(py)]·2H₂O (3) (dtcpyr=S₂CNC₄H^– ₈) have been synthesized and structurally characterized by IR, Raman, UV–Vis, ¹H NMR, ¹³C NMR spectroscopies and single-crystal X-ray diffraction studies. Their structure and bonding features are discussed. Compounds 1 and 2 show a good third-order optical nonlinearity, as measured by degenerate four-wave mixing technique.     

Facially Dispersed Polyhydride Cu9 and Cu16 Clusters Comprising Apex-Truncated Supertetrahedral and Square-Face-Capped Cuboctahedral Copper Frameworks

By using a linear tetraphosphine, meso-bis[(diphenylphosphinomethyl)phenylphosphino]methane (dpmppm), nona- and hexadecanuclear copper hydride clusters, [Cu₉H₇(μ-dpmppm)₃]X₂ (X=Cl ( 1 a ), Br ( 1 b ), I ( 1 c ), PF₆ ( 1 d )) and [Cu₁₆H₁₄(μ-dpmppm)₄]X₂ (X₂=I₂ ( 2 c ), (4/3) PF₆⋅(2/3) OH ( 2 d )) were synthesized and characterized. They form copper-hydride cages of apex-truncated supertetrahedral {Cu₉H₇}²⁺ and square-face-capped cuboctahedral {Cu₁₆H₁₄}²⁺ structures. The hydride positions were estimated by DFT calculations to be facially dispersed around the copper frameworks. A kinetically controlled synthesis gave an unsymmetrical Cu₈H₆ cluster, [Cu₈H₆(μ-dpmppm)₃]²⁺ ( 3 ), which readily reacted with CO₂ to afford linear Cu₄ complexes with formate bridges, leading to an unprecedented hydrogenation of CO₂ into formate catalyzed by {Cu₄(μ-dpmppm)₂} platform. The results demonstrate that new motifs of copper hydride clusters could be established by the tetraphosphine ligands, and the structures influence their reactivity.     

[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].     

The conformations of two copper(I) complexes of 1H‐benzimidazole‐2(3H)‐thione and thiosaccharinate

(Acetonitrile‐1κN)[μ‐1H‐benzimidazole‐2(3H)‐thione‐1:2κ²S:S][1H‐benzimidazole‐2(3H)‐thione‐2κS]bis(μ‐1,1‐dioxo‐1λ⁶,2‐benzothiazole‐3‐thiolato)‐1:2κ²S³:N;1:2κ²S³:S³‐dicopper(I)(Cu—Cu), [Cu₂(C₇H₄NO₂S₂)₂(C₇H₆N₂S)₂(CH₃CN)] or [Cu₂(tsac)₂(Sbim)₂(CH₃CN)] [tsac is thiosaccharinate and Sbim is 1H‐benzimidazole‐2(3H)‐thione], (I), is a new copper(I) compound that consists of a triply bridged dinuclear Cu—Cu unit. In the complex molecule, two tsac anions and one neutral Sbim ligand bind the metals. One anion bridges via the endocyclic N and exocyclic S atoms (μ‐S:N). The other anion and one of the mercaptobenzimidazole molecules bridge the metals through their exocyclic S atoms (μ‐S:S). The second Sbim ligand coordinates in a monodentate fashion (κS) to one Cu atom, while an acetonitrile molecule coordinates to the other Cu atom. The Cu^I—Cu^I distance [2.6286 (6) Å] can be considered a strong `cuprophilic' interaction. In the case of [μ‐1H‐benzimidazole‐2(3H)‐thione‐1:2κ²S:S]bis[1H‐benzimidazole‐2(3H)‐thione]‐1κS;2κS‐bis(μ‐1,1‐dioxo‐1λ⁶,2‐benzothiazole‐3‐thiolato)‐1:2κ²S³:N;1:2κ²S³:S³‐dicopper(I)(Cu—Cu), [Cu₂(C₇H₄NO₂S₂)₂(C₇H₆N₂S)₃] or [Cu₂(tsac)₂(Sbim)₃], (II), the acetonitrile molecule is substituted by an additional Sbim ligand, which binds one Cu atom via the exocylic S atom. In this case, the Cu^I—Cu^I distance is 2.6068 (11) Å.     

Ribbon and Self‐Penetrated Hybrid Copper Molybdates with Ancillary Bis(4‐pyridylmethyl)piperazine Ligands

Hybrid copper molybdates containing the long‐spanning bis(4‐pyridylmethyl) piperazine (bpmp) ligand were prepared via hydrothermal synthesis and structurally characterized by single‐crystal X‐ray diffraction. The reduced copper phase and major product [Cu₄(MoO₄)₂(bpmp)₄]_n ( 1 ) shows 1D ribbon motifs with embedded {Cu^I₂O₂} dimeric units, built from the bpmp pillaring of [Cu₄(MoO₄)₂] linear clusters. The oxidized copper phase and minor product {[Cu₂(MoO₄)₂(bpmp)₄] · 24H₂O}_n ( 2 ) displays [Cu(bpmp)₂]_n²ⁿ⁺ mutually inclined interpenetrated cationic layers cross‐pillared by molybdate tetrahedra into an unprecedented 6‐connected self‐penetrated network with 4⁸5²6⁵ topology.     

Unified reciprocity of dithiophosphate by dichalcogenophosph(in)ate ligands on copper hydride nanoclusters via ligand exchange reaction

A structural study of ligand exchange on chalcogen‐passivated copper nanoclusters is far less developed. Herein, we report the synthesis of polyhydrido copper nanoclusters [Cu₂₀H₁₁{Se₂P(O ⁱBu)₂}₉] ( 2 ) passivated by Se‐donor ligands via ligand replacement reaction on [Cu₂₀H₁₁{S₂P(O ⁱPr)₂}₉] ( 1 ) with NH₄[Se₂P(O ⁱBu)₂]. In parallel to the synthesis of 2 , cluster [Cu₂₀H₁₁{S₂P(CH₂CH₂Ph)₂}₉] ( 4 ) was produced by the ligand exchange reaction on a new derivative of 1 , that is [Cu₂₀H₁₁{S₂P(O ⁿPr)₂}₉] ( 3 ). Solid state structures of both clusters 2 and 4 were unequivocally established by single‐crystal X‐ray diffraction studies and cluster 4 epitomizes exceptional case to preserve both the shape and size of the nanocluster during the course of ligand exchange. Structurally precise cluster 2 is the second example where the copper hydride nanocluster is stabilized by Se‐donor ligands. The anatomy of 2 can be visualized as a twisted cuboctahedral Cu₁₃ core, two triangular faces of which are capped by a Cu₆ cupola and a single Cu atom along the C₃ rotational axis.     

3D Ni(Ⅱ)/Cu(Ⅱ) Supermolecular Frameworks Based on Pyridylamine and Fumarate Co-ligands Containing a Trinodal (4,5,6)-Connected Network and a (H2O)16 Water Cluster

Two new complexes, [Ni(dpypda)(H₂O)₃]·(fum) ( 1 ) and [Cu₂(dpypda)₂(fum)₂]_n·8nH₂O ( 2 ) (dpypda=N²,N⁴‐di(pyridin‐2‐yl)pyrimidine‐2,4‐diamine, fum=fumarate), have been synthesized and characterized by single‐crystal X‐ray diffraction. Complex 1 is a discrete unit, exhibiting a (4,5,6)‐connected framework formed by hydrogen bonding interactions and electrostatic interactions between free fum dianions and mononuclear [Ni(dpypda)(H₂O)₃]²⁺ cations. However, in complex 2 , two crystallographically independent fum dianions adopt the alternative mode of mixed monodentate bridging and chelating and bis(monodentate) bridging Cu(II) atoms to produce a one‐dimensional (1D) in?nite zigzag chain. And there are unique (H₂O)₁₆ water clusters which consist of one cyclic (H₂O)₄ tetramer and two cyclic (H₂O)₅ pentamer with six dangling water molecules in its 3D supramolecular framework. Both 1 and 2 are characterized by IR and elemental analysis, and the TG properties were also investigated for 2 .     

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).     

Cations Controlling the Chiral Assembly of Luminescent Atomically Precise Copper(I) Clusters

Chiral assembly and asymmetric synthesis are critically important for the generation of chiral metal clusters with chiroptical activities. Here, a racemic mixture of [K(CH₃OH)₂(18‐crown‐6)]⁺[Cu₅(S^tBu)₆]^? ( 1?CH₃OH ) in the chiral space group was prepared, in which the chiral red‐emissive anionic [Cu₅(S^tBu)₆]^? cluster was arranged along a twofold screw axis. Interestingly, the release of the coordinated CH₃OH of the cationic units turned the chiral 1?CH₃OH crystal into a mesomeric crystal [K(18‐crown‐6)]⁺[Cu₅(S^tBu)₆]^? ( 1 ), which has a centrosymmetric space group, by adding symmetry elements of glide and mirror planes through both disordered [Cu₅(S^tBu)₆]^? units. The switchable chiral/achiral rearrangement of [Cu₅(S^tBu)₆]^? clusters along with the capture/release of CH₃OH were concomitant with an intense increase/decrease in luminescence. We also used cationic chiral amino alcohols to induce the chiral assembly of a pair of enantiomers, [d /l ‐valinol(18‐crown‐6)]⁺[Cu₅(S^tBu)₆]^? ( d /l ‐Cu_5V ), which display impressive circularly polarized luminescence (CPL) in contrast to the CPL‐silent racemic mixture of 1?CH₃OH and mesomeric 1 .     

Assemblies of 1D and 2D Copper(II) Chiral Coordination Polymers by Salicylaldehyde Schiff Bases: Synthesis,Crystal Structures,and Magnetic Properties

Reaction of CuCl₂ · 2H₂O with chiral Schiff bases and sodium dicyanamide led to the formation of two chiral copper(II) coordination polymers, namely [Cu₄(L¹)₂(dca)₄]_n ( 1 ) and [Cu₂(L²)(μ‐Cl)(dca)(H₂O)]_n · nH₂O ( 2 ) {H₂L¹ = (1R, 3S)‐N′,N′′‐bis[salicylidene]‐1,3‐diamino‐ 1,2,2‐trimethylcyclopentane, H₂L² = (1R, 3S)‐N′,N′′‐bis[3‐ethoxysalicylidene]‐1,3‐diamino‐ 1,2,2‐trimethylcyclopentane, dca = dicyanamide}. Both complexes were structurally characterized by elemental analyses, IR spectroscopy and single‐crystal X‐ray diffraction. Complex 1 exhibits a two‐dimensional polymeric structure formed by single dca bridging tetranuclear Cu₄ units. Complex 2 displays a left‐handed helical chain structure constructed from Cu₂ dimers with single dca bridges. The chirality of 1 and 2 was confirmed by circular dichroism (CD) measurements in solution. Both complexes exhibit strong antiferromagnetic couplings with J = –308(4) cm^–1 for 1 and J = –123(1) cm^–1 for 2 in 2–300 K.     

Two different one‐dimensional structural motifs in [catena‐{Cu(tacn)}2Pd(CN)4]Br2·[catena‐Cu(tacn)Pd(CN)4]2·H2O (tacn is 1,4,7‐triazacyclononane)

The title compound, catena‐poly[[bis[(triazacyclononane‐κ³N,N′,N′′)copper(II)]‐di‐μ‐cyanido‐κ⁴N:C‐palladate(II)‐di‐μ‐cyanido‐κ⁴C:N] dibromide bis[[(triazacyclononane‐κ³N,N′,N′′)copper(II)]‐μ‐cyanido‐κ²N:C‐[dicyanidopalladate(II)]‐μ‐cyanido‐κ²C:N] monohydrate], {[Cu₂Pd(CN)₄(C₆H₁₅N₃)₂]Br₂·[Cu₂Pd₂(CN)₈(C₆H₁₅N₃)₂]·H₂O}_n, (I), was isolated from an aqueous solution containing tacn·3HBr (tacn is 1,4,7‐triazacyclononane), Cu²⁺ and tetracyanidopalladate(2−) anions. The crystal structure of (I) is essentially ionic and built up of 2,2‐electroneutral chains, viz. [Cu(tacn)(NC)–Pd(CN)₂–(CN)–], positively charged 2,4‐ribbons exhibiting the composition {[Cu(tacn)(NC)₂–Pd(CN)₂–Cu(tacn)]²ⁿ⁺}_n, bromide anions and one disordered water molecule of crystallization. The O atom of the water molecule occupies two unique crystallographic positions, one on a centre of symmetry, which is half occupied, and the other in a general position with one‐quarter occupancy. One of the tacn ligands also exhibits disorder. The formation of two different types of one‐dimensional structural motif within the same structure is a unique feature of this compound.     

Crystal Structure and Characterization of Pd(II) Bis(diiso‐propyldithiocarbamate) Complex

The crystal and molecular structure of [Pd(iPr₂dtc)₂] (dtc = dithiocarbamate) have been determined by X‐ray crystallography. The unit cell of the crystal structure consists of two discrete monomelic molecules of [Pd(iPr₂dtc)₂]. The Pd(II) ion has an square‐planar geometry. The electronic and IR spectral data are in agreement with the X‐ray structure. The TG data indicate slight degradation of a few percent.     

Effect of solvent and remote ligand substituents on the photochemical behaviour of copper(II) dithiocarbamates and dithiophosphates

The photochemical properties of bis(dithiocarbamato)Cu^II, Cu(R¹dtc)₂, and bis(dithiophosphato)Cu^II, Cu(R₂ ²dtp)₂, complexes with different remote ligand substituents (R¹ = piperidine, morpholine, pyrrolidine and 4-phenylpiperazine; R² = Me, Et and i-Pr) have been studied in chloromethanes (CCl₄, CHCl₃, CH₂Cl₂), chloromethanes/EtOH and PhMe. The monomeric species Cu^II(R¹dtc)Cl and its chloride-bridged dimeric form Cu₂(R¹dtc)₂Cl₂ were subsequently obtained during Cu(R¹dtc)₂ photolysis in chloromethane/EtOH mixtures and the steady-state concentration of Cu₂(R¹dtc)₂Cl₂ was found to depend on the EtOH content in the mixed solvents as well as on the nature of R¹ and the oxidising ability of the chloromethane. The appearance of the mixed-ligand complex Cu^II(R₂ ²dtp)Cl has been observed as an intermediate photoproduct after longer u.v.-irradiation of Cu(R₂ ²dtp)₂ in chloromethanes/EtOH.     

Assembly and Crystal Structure of a Novel 1—D Coordination Polymer of Copper（Ⅱ）with Thiocyanate and 4—Cyanopyridine

A novel one‐dimensional coordination polymer, Catena‐poly [bis(4‐cyano‐pyridyl) copper(II)‐di‐thiocyanate], ¹_∞ [Cu^II‐(cypy)₂(μ_N.S‐SCN)₂] (cypy = 4‐cyano‐pyridyl), was synthesized in a solution reaction of Cu(NO₃)₂·3H₂O, 4‐cyano‐pyridine and KSCN in mole ratio of 1:2:2 at room temperature. Its crystal structure was determined by single‐crystal X‐ray diffraction. The crystal belongs to monoclinic crystal system, space group P2₁/c with cell parameters a = 1.0719(2), b = 1.8441(4), c =0.9144(2) nm, β = 110.49(3)° and Z = 4. A full‐matrix least‐squares refinement gave R₁ = 0. 0393 and wR₂= 0.0916 for 1554 reflections having 1 >2σ(I). The crystal is thermally stable up to approximately 170 °C.     

Synthesis and Structural Characterization of Six Pentanuclear and Tetranuclear Mo/W‐Cu‐S Clusters with Bis(diphenylphosphanyl) Methane

Six heterothiometalic clusters, namely, [WS₄Cu₄(dppm)₄](ClO₄)₂ · 2DMF · MeCN ( 1 ), [MoS₄Cu₄(dppm)₄](NO₃)₂ · MeCN ( 2 ) [MoS₄Cu₃(dppm)₃](ClO₄) · 4H₂O ( 3 ), [WS₄Cu₃(dppm)₃](NO₃) · 4H₂O ( 4 ), [WS₄Cu₃(dppm)₃]SCN · CH₂Cl₂ ( 5 ), and [WS₄Cu₃(dppm)₃]I · CH₂Cl₂ ( 6 ) [dppm = bis (diphenylphosphanyl)methane] were synthesized. Compounds 1 – 4 were obtained by the reactions of (NH₄)₂MS₄ (M = Mo, W) with [Cu₂(μ₂‐dppm)₂(MeCN)₂(ClO₄)₂] {or [Cu(dppm)(NO₃)]₂} in the presence of 1,10‐phen in mixed solvent (CH₃CN/CH₂Cl₂/DMF for 1 and 2 , CH₂Cl₂/CH₃OH/DMF for 3 and 4 . Compounds 5 and 6 were obtained by one‐pot reactions of (NH₄)₂WS₄ with dppm and CuSCN (or CuI) in CH₂Cl₂/CH₃OH. These clusters were characterized by single‐crystal X‐ray diffraction as well as IR, ¹H NMR, and ³¹P NMR spectroscopy. Structure analysis showed that compounds 1 and 2 are “saddle‐shaped” pentanuclear cationic clusters, whereas compounds 3 – 6 are “flywheel‐shaped” tetranuclear cationic clusters. In 1 and 2 , the MS₄^2– unit (M = W, Mo) is coordinated by four copper atoms, which are further bridged by four dppm molecules. In compounds 3 – 6 , the MS₄^2– unit is coordinated by three copper atoms and each copper atom is bridged by three dppm ligands.     

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.     

Synthesis,Structure, and Magnetic Properties of a Copper(II) Metal‐Organic Framework with Biphenyl‐2,2′,4,4′‐tetracarboxylic Acid

The 2D Cu^II metal‐organic framework [Cu₂(bptc)(H₂O)₄]_n · 4nH₂O ( 1 ) (H₄bptc = biphenyl‐2,2′,4,4′‐tetracarboxylic acid) was hydrothermally synthesized and characterized by single‐crystal X‐ray diffraction and magnetic measurements. In the structure, bptc^4– serves as a twisted Π‐shaped organic building block to connect paddlewheel [Cu₂(COO)₄] dinuclear units and mononuclear units through 2‐/2′‐carboxylate and 4‐/4′‐carboxylate, respectively. According to the magnetic analysis using a dimer‐plus‐monomer model, strong antiferromagnetic coupling is operative within the dinuclear unit (J = –311 cm^–1 based on H = –J S ₁ S ₂), and the compound behaves like a mononuclear molecule at low temperature.