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

Systematics of stable copper and silver clusters protected by small bite chelating bidentate sulfur and selenium ligands related to their polyhedral cavities: analogies to aliphatic compounds and three-dimensional spherical aromatic systems

Silver and copper clusters capped by external chelating dithiolate ligands can be classified according to the cavities in their central coinage metal polyhedra. Silver clusters composed exclusively of fused tetrahedra are analogous to simple saturated organic compounds. The only interstitial atom that can be fit into an Ag4 tetrahedron is hydrogen. Silver polyhedra with larger trigonal prismatic or cubic cavities, including highly distorted cubic cavities, can accommodate halide and chalcogenide anions. The still larger 12-vertex icosahedral and cuboctahedral coinage metal cavities can accommodate oxoanions of the types SO32- and SO42- and their heavier congeners or alternatively interstitial coinage or platinum group metals leading to central M'@M12 units. Copper clusters with central cuboctahedra and silver clusters with central icosahedra possessing interstitial metal atoms approximate sphericality and provide examples of electron-rich metal superatoms with an average metal oxidation state of less than +1. Such copper cluster superatoms have two extra electrons corresponding to a filled 1S2 superatomic orbital. The silver cluster superatoms are electron richer with eight extra electrons corresponding to filled 1S2 + 1P6 superatomic orbitals. In these silver clusters seven or eight faces of the central Ag12 icosahedron are capped by additional silver atoms in order to provide these additional electrons.

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 Se^2-, 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.

Synthesis and structural characterization of inverse-coordination clusters from a two-electron superatomic copper nanocluster

We have synthesized and structurally characterized a series of centred cuboctahedral copper clusters, namely [Cu13{S2CNR2}6{C[triple bond, length as m-dash]CR'}4](PF6), 1a-d (where a: R = n Bu, R' = CO2Me; b: R = n Bu, R' = CO2Et; c: R = iPr, R' = CO2Et; d: R = n Pr, R' = 3,5-(CF3)2C6H3); [Cu12(μ12-S){S2CNR2}6{C[triple bond, length as m-dash]CR'}4], 2a-c; [Cu12(μ12-Cl){S2CNR2}6{C[triple bond, length as m-dash]CR'}4](PF6), 3a-e (where e: R = n Bu, R' = Ph); [Cu12(μ12-Br){S2CN n Bu2}6{C[triple bond, length as m-dash]CPh}4](PF6), 4e; and [Cu12(μ12-Cl)(μ3-Cl){S2CN n Bu2}6{C[triple bond, length as m-dash]CCO2Me}3]+ 5a. Cluster 1a is the first structurally characterized copper cluster having a Cu13 centered cuboctahedral arrangement, a miniature of the bulk copper fcc structure. Furthermore, the partial Cu(0) character in the 2-electron superatoms 1 was confirmed by XANES. Inverse coordination clusters 2-5 are the first examples of copper clusters containing main group elements (Cl, Br, S) with a hyper-coordination number, twelve. A combined theoretical and experimental study was performed, which shows that the central copper (formally Cu1-) in nanoclusters 1 can be replaced by chalcogen/halogen atoms, resulting in the formation of clusters 2-5 which show enhanced luminescence properties and increase in the ionic component of the host-guest interaction as Br ≈ Cl > S > Cu, which is consistent with the Cu-X Wiberg indices. The new compounds have been characterized by ESI-MS, 1H, 13C NMR, IR, UV-visible, emission spectroscopy, and the structures 2a-b, 3d-e, 4e and 5a were established by X-ray diffraction analysis.

Discrete copper(i) clusters with Cu6P6Se6 and Cu6P4Se6 cores

The reactions of chalcogenophosphinites with copper(I) metal salts are shown to yield highly stable, multi-metallic copper-chalcogen based clusters with novel topologies.