Jian-Hong Liao

[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 ((1)H, (31)P), 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 1S(2) 1P(6) configuration, as confirmed by DFT calculations.

A Nanospheric Polyhydrido Copper Cluster of Elongated Triangular Orthobicupola Array: Liberation of H2 from Solar Energy

An unprecedented air-stable, nanospheric polyhydrido copper cluster, [Cu20H11(S2P(O(i)Pr)2)9] (1H), which is the first example of an elongated triangular orthobicupola array of Cu atoms having C3h symmetry, was synthesized and characterized. Its composition was primarily determined by electrospray ionization mass spectrometry, and it was fully characterized by (1)H, (2)H, and (31)P NMR spectroscopy and single-crystal X-ray diffraction (XRD). The structure of complex 1H can be expressed in terms of a trigonal-bipyramidal [Cu2H5](3-) unit anchored within an elongated triangular orthobicupola containing 18 Cu atoms, which is further stabilized by 18 S atoms from nine dithiophosphate ligands and six capping hydrides. The positions of the 11 hydrides revealed by low temperature XRD were supported by a density functional theory investigation on the simplified model [Cu20H11(S2PH2)9] with C3h symmetry. 1H is capable of releasing H2 gas upon irradiation with sunlight, under mild thermal conditions (65 °C), or in the presence of acids at room temperature.

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

The syntheses of the first rhombicuboctahedral copper polyhydride complexes [Cu28 (H)15 (S2 CNR)12 ]PF6 (NR=N(n) Pr2 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)(S2 CNR)6 ](+) upon exposure of solutions to sunlight, under mild thermolytic conditions, and on reaction with weak (or strong) acids.

A twelve-coordinated iodide in a cuboctahedral silver(I) skeleton.

Three new halide-centered octanuclear silver(I) complexes, [Ag8(X){S2P(CH2CH2Ph)2}6](PF6), X = F(-), 1; Cl(-), 2; Br(-), 3; were prepared in the presence of the corresponding halide anions with silver(I) salts and dithiophosphinate ligands. Structure analyses displayed that a Ag8 cubic core can be modulated by the size effect of the central halide; however, an iodide-centered Ag8 cluster was not found under similar reaction conditions. Interestingly, a luminescent dodecanuclear silver(I) cluster, [Ag12(μ12-I)(μ3-I)4{S2P(CH2CH2Ph)2}6](I), 4; was then synthesized. The structure of 4 contains a novel μ12-I at the center of a cuboctahedral silver(I) atom cage, which is further stabilized by four additional μ3-I and six dithiophosphinate ligands. To the best of our knowledge, the μ12-I revealed in 4 is the highest coordination number for a halide ion authenticated by both experimental and computational studies. Previously, the μ12-I was only observed in [PyH][{TpMo(μ3-S)4Cu3}4(μ12-I)]. The synthetic details, spectroscopic studies including multinuclear NMR and ESI-MS, structure elucidations by single crystal X-ray diffraction, and photoluminescence of 4 are reported herein.

Anion Encapsulation and Geometric Changes in Hepta- and Hexanuclear Copper(I) Dichalcogeno Clusters: A Theoretical and Experimental Investigation

Whereas stable octanuclear clusters of the type M(I)8(E(∩)E)6 (M = Cu, Ag; E(∩)E = dithio or diseleno ligand) are known for being able to encapsulate a hydride or main-group anion under some circumstances, only the related hydride-containing heptanuclear [M(I)]7(H)(E(∩)E)6 and empty hexanuclear [M(I)]6(E(∩)E)6 species have been characterized so far. In this paper we investigate by the means of theoretical calculations and experiments the viability of empty and anion-centered clusters of the type [Cu(I)]7(X)(E(∩)E)6 and [Cu(I)]6(X)(E(∩)E)6 (X = vacancy, H or a main-group atom). The theoretical prediction for the existence of anion-containing heptanuclear species, the shape of which is modulated by the anion nature and size, have been fully confirmed by the synthesis and characterization of [Cu7(X){S2P(O(i)Pr)2}6] (X = H, Br). This consistency between experiment and theory allows us to predict the stability and shape-modulated structure of a whole series of [Cu(I)]7(X)(E(∩)E)6 (X = vacancy, H, O, S, halogen) and [Cu(I)]6(X)(E(∩)E)6 (X = H, halogen) clusters.

[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 {S2 P(OiPr)2 }12 ] (1H ) was synthesized and structurally characterized. The molecular structure of 1H 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 (S2 PH2 )12 ].

[Ag20{S2P(OR)2}12]: A Superatom Complex with a Chiral Metallic Core and High Potential for Isomerism

The synthesis and structural determination of a silver nanocluster [Ag20 {S2 P(OiPr)2 }12 ] (2), which contains an intrinsic chiral metallic core, is produced by reduction of one silver ion from the eight-electron superatom complex [Ag21 {S2 P(OiPr)2 }12 ](PF6 ) (1) by borohydrides. Single-crystal X-ray analysis displays an Ag20 core of pseudo C3 symmetry comprising a silver-centered Ag13 icosahedron capped by seven silver atoms. Its n-propyl derivative, [Ag20 {S2 P(OnPr)2 }12 ] (3), can also be prepared by the treatment of silver(I) salts and dithiophosphates in a stoichiometric ratio in the presence of excess amount of [BH4 ](-) . Crystal structure analyses reveal that the capping silver-atom positions relative to their icosahedral core are distinctly different in 2 and 3 and generate isomeric, chiral Ag20 cores. Both Ag20 clusters display an emission maximum in the near IR region. DFT calculations are consistent with a description within the superatom model of an 8-electron [Ag13 ](5+) core protected by a [Ag7 {S2 P(OR)2 }12 ](5-) external shell. Two additional structural variations are predicted by DFT, showing the potential for isomerism in such [Ag20 {S2 P(OR)2 }12 ] species.

Tetrahedral-shaped anions as a template in the synthesis of high-nuclearity silver(I) dithiophosphate clusters.

Novel Ag(32) clusters, [Ag(16)(EO(4)){S(2)P(OEt)(2)}(12)](2) (PF(6))(4) (E = S, 1; Se, 2) and [Ag(16)(MO(4)){S(2)P(OEt)(2)}(12)](2)(PF(6))(4) (M = Cr, 3; Mo, 4), were prepared in situ from the addition of a tetrahedral-shaped anion as a template to the pentanuclear extended chain [Ag(5){S(2)P(OEt)(2)}(4)](n)(PF(6))(n).

A μ9-iodide in a tricapped trigonal-prismatic geometry.

Two luminescent, undecanuclear silver complexes [Ag(11)(μ(9)-I)(μ(3)-I)(3){E(2)P(O(i)Pr)(2)}(6)](PF(6)) [E = S (yellow), 1; Se (orange), 2], containing the first μ(9)-iodine inscribed at the center of a pentacapped trigonal-prismatic silver skeleton, were reported.

[Cu13{S2CNnBu2}6(acetylide)4]+: A Two-Electron Superatom

The first structurally characterized copper cluster with a Cu13 centered cuboctahedral arrangement, a model of the bulk copper fcc structure, was observed in [Cu13 (S2 CNn Bu2 )6 (C≡CR)4 ](PF6 ) (R=C(O)OMe, C6 H4 F) nanoclusters. Four of the eight triangular faces of the cuboctahedron are capped by acetylide groups in μ3  fashion, and each of the six square faces is bridged by a dithiolate ligand in μ2 ,μ2 fashion, which leads to a truncated tetrahedron of twelve sulfur atoms. DFT calculations are fully consistent with the description of these Cu13 clusters as two-electron superatoms, that is, a [Cu13 ]11+ core passivated by ten monoanionic ligands, with an a1 HOMO containing two 1S jellium electrons.