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Copper hydrides are very useful in hydrogenation reactions. We report a stable Stryker-type copper hydride reagent protected by hemilabile phosphines: [Cu8H6(dppy)6](OTf)2 (Cu8-H, dppy = diphenylphosphino-2-pyridine). The metal core of this cluster has a bicapped octahedral configuration, and the copper-bound hydrides each triply bridges over a triangular face of the octahedron. This cluster is attractive due to its facile preparation and excellent stability under ambient conditions. The comparable activity and selectivity both in the stoichiometric and catalytic reactions make Cu8-H a promising alternative to Stryker's reagent.

The identification of hydride(s) in gold nanoclusters is a challenging task, due to the instability of gold nanoclusters containing hydrides. Herein, we report two ultrastable hydrido gold nanoclusters protected by phosphine ligands: [Au20(PPh3)12H3](SbF6)3 (1H) and [Au20(PPh3)12H2(2-COOH-PhS)](PF6)3 (2H). The presence of hydrides in gold(0)-gold(i) nanoclusters is clearly demonstrated by ESI mass spectrometry and NMR spectroscopy. Single crystal structural determination reveals that both nanoclusters have an unprecedented Au20 core consisting of a Au9 unit and a Au11 unit. Such cores derived from the connection of different basic units are important for understanding the evolution and stability of metal nanoclusters. The hydride (H-) was also verified by a charge distribution calculation.

We report the total structure determination of a covalently bonded nanocluster polymer [Au7Ag9(dppf)3(CF3CO2)7BF4]n (1). This features a one-dimensional linear chain, consisting of unique molecular building blocks, Au7Ag8(dppf)3(CF3CO2)7 clusters, which are linked together by Ag-O bonds rather than Au-Au interactions or bidentate organic bridges as previously reported.

We report a series of Ag-S nanoscale clusters in an attempt to understand the growth process of Ag2S clusters. UV-vis monitoring and crystallization at different stages of the reaction map out the cluster growth steps from Ag31S3(StBu)17(tfa)8(MeCN)4 (tfa = trifluoroacetate), to Ag45S7(StBu)24(tfa)7 to [Ag62S13(StBu)32(tfa)2](tfa)2, showing sequential eye-catching color changes. The cluster growth is associated with the in situ generation of S2-, which comes from the C-S bond cleavage of tert-butyl thiolate.

An alkynyl-protected gold nanocluster [Au40(PhC[triple bond, length as m-dash]C)20(dppm)4](SbF6)4 (dppm = bis(diphenylphosphino)methane) (1) has been synthesized. Single-crystal X-ray diffraction reveals that the cluster has a face-centered cubic (FCC) Au34 kernel that is made up of two Au20 units via sharing a rectangular face. Two linear PhC[triple bond, length as m-dash]C-Au-C[triple bond, length as m-dash]CPh staple motifs are located around the central part of the Au34 core, and four L-shaped PhC[triple bond, length as m-dash]C-Au-P^P staple motifs are located at the four corners of the Au34 core. Cluster 1 and [Au38(PhC[triple bond, length as m-dash]C)20(PPh3)4](CF3SO3)2 both have the FCC Au34 core, and it is found that the diphosphine ligands bringing two more Au atoms into the system have significant effects on the optical properties and stability of the clusters. The combination of a diphosphine ligand and an alkynyl ligand is helpful in generating new ligand-protected metal nanoclusters.

Gold(i) phosphinopyridyl clusters [Au 9 (PNC) 6 ](BF 4 ) 3 (1) and [Au 11 (PNC) 6 (PPh 3 ) 2 ](BF 4 ) 5 (2) (PNC = 2-diphenylphosphinopyridyl monoion) are assembled. In contrast to the green luminescence of 1, 2 is brightly orange emissive in CH 2 Cl 2 , which shows the presence of unsupported Au I -Au I interactions in solution. Besides, 1 and 2 can selectively light up the mitochondria of living cells.

A gold(i)-silver(i) cluster bearing six carboxylate groups has been synthesized through the oxidation of its aldehyde precursor and the Au6 core of this cluster displays an octahedral or a trigonal prismatic configuration depending on the crystallization conditions. The reversible interconversion between these two isomers can be triggered in the solid state by the addition or removal of acetonitrile solvent molecules. Interestingly, luminescence changes were observed as each configuration shows different emission colors, yellow for octahedral type and red for the trigonal prismatic one.

We report a unique intercluster compound comprising a Ag41 cage encapsulating a divacant [α-SiW(10)O37](10-) anion and a complete [β-SiW(12)O40](4-) anion as a counteranion. Two electro-redox centers associated with the inner and outer POM anions show interesting electrochemical behaviours, because the stable Ag41 cage acts as an electron transfer mediator.

The first silver cluster encapsulating an organic anion-squarate dianion-has been synthesized. Two C4O4(2-) anions arranged in a staggered sandwich type arrangement are confined in the Ag24 cage. The incorporation of squarate anions into the silver alkynyl system leads to the red shift of absorption of the cluster in comparison to silver squarate.

Enantiopure chiral cubic cages have been diastereoselectively synthesized for the first time. Chiral amines lead to the isolation of O symmetric homochiral cubic cages, while an achiral amine gives a racemic mixture. CD enhancement is observed as a result of configuration rigidity.

A silver alkynyl cluster containing a Ag70 shell and two lacunary [PW9O34](9-) templating ions was synthesized by an ionothermal approach. Fast core-shell electronic communication between silver(i) centers and polyoxometalates was verified via cyclic voltammetry studies in [BMIm]BF4.

Blue or yellow-green emission is observed from two different crystal types of the same gold(I)-silver(I) molecular cluster [SAu(3)Ag(L1)(3)](BF(4))(2) (L1 = 2-diphenylphosphino-4-methylpyridine) depending on the crystallization conditions; structural data suggest that intermolecular Au···Au interactions account for the luminescence vapochromic responses; a similar observation was made on two other pairs of analogues.

Methanol drives the blue emissive complex, [Cu(2)(dppy)(3)(MeCN)](BF(4))(2) (dppy = diphenylphosphino-pyridine), with a head-to-tail arrangement of the three bridging phosphine ligands to convert to its linkage isomer (head-to-head, green emissive) in the solid state, and the transformation could be reversibly realized through recrystallization in different solvents.

An unprecedented trigonal prismatic (μ(6)-C)Au(6) structure has been found in a novel gold(I)-copper(I) cluster with a hypercoordinated carbon, [CAu(6)Cu(2)(dppy)(6)](BF(4))(4); the incorporation of copper ions enhances the rigidity and integrity of the cluster and turns on the bright red solution luminescence., (© The Royal Society of Chemistry 2011)

A novel nonadecanuclear silver double cage was isolated, in which a square antiprism and a pentacapped pentagonal prism templated by a chloride ion share a tetragonal face to form a snowman-like cluster that is held together by bridging alkynyl groups and trifluoroacetates.

Unprecedented eta 3 pi-donor behavior of the benzyltrimethy-lammonium ion is observed in the polymeric silver(I) complex [(PhCH2NMe3)Ag7(C2)(CF3CO2)6]n that comprises a columnar backbone constructed from the fusion of Ag8 square antiprisms each enclosing an acetylide dianion.

9-Fluorenylidenemalononitrile reacts with 10-methyl-9,10-dihydroacridine in deaerated acetonitrile under irradiation with lambda > 320 nm to give a coupling product 9-dicyanomethyl-9-(10'-methyl-9'-acridinyl)fluorene, characterized by X-ray crystallographic, MS and NMR analyses.