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The first examples of gold(I) trimethylsilylchalcogenolate complexes were synthesized and their reactivity showcased in the preparation of a novel gold-copper-sulfur cluster [Au4Cu4S4(dppm)2] (dppm=bis(diphenylphosphino)methane). The unprecedented structural chemistry of this compound gives rise to interesting optoelectronic properties, including long-lived orange luminescence in the solid state. Through time-dependent density functional theory calculations, this emission is shown to originate from ligand-to-metal charge transfer facilitated by Au⋅⋅⋅Cu metallophilic bonding. [ABSTRACT FROM AUTHOR]

Silicon quantum dots (Si-QDs) of various diameters were formed by annealing of Si-rich silicon nitride (Si3Nx) films synthesized using plasma-enhanced chemical vapor deposition. To investigate the effect of annealing temperature on the luminescence of this system, samples were annealed at temperatures from 400 to 1000 °C. Photoluminescence (PL), x-ray absorption near edge spectroscopy, elastic recoil detection, and Fourier-transform infrared spectroscopy measurements were used for characterization. The authors found that luminescence originated from both quantum confinement effects (QCE) and defects, and that hydrogen passivation affects the PL intensity. For lower annealing temperatures, radiative recombination due to the QCE of the Si-QDs films was observed. For higher annealing temperatures (above 600 °C), desorption of hydrogen from the sample caused the PL intensity to decrease significantly. Si3Nx films with a lower Si content were less sensitive to this reduction in PL intensity after annealing at high temperatures (above 600 °C). Our results emphasize the importance of hydrogenation of the silicon nitride matrix if Si QDs are to be used in optoelectronic devices. [ABSTRACT FROM AUTHOR]

As a part of efforts to prepare new 'metallachalcogenolate' precursors and develop their chemistry for the formation of ternary mixed-metal chalcogenide nanoclusters, two sets of thermally stable, N-heterocyclic carbene metal-chalcogenolate complexes of the general formula [(IPr)Ag−ESiMe3] (IPr=1,3-bis(2,6-diisopropylphenyl)imidazolin-2-ylidene; E=S, 1; Se, 2) and [( iPr2-bimy)Cu−ESiMe3]2 ( iPr2-bimy=1,3-diisopropylbenzimidazolin-2-ylidene; E=S, 4; Se, 5) are reported. These are prepared from the reaction between the corresponding carbene metal acetate, [(IPr)AgOAc] and [( iPr-bimy)CuOAc] respectively, and E(SiMe3)2 at low temperature. The reaction of [(IPr)Ag−ESiMe3] 1 with mercury(II) acetate affords the heterometallic complex [{(IPr)AgS}2Hg] 3 containing two (IPr)Ag−S− fragments bonded to a central HgII, representing a mixed mercury-silver sulfide complex. The reaction of [( iPr2-bimy)Cu-SSiMe3]2, which contains a smaller N-heterocyclic-carbene, with mercuric(II) acetate affords the high nuclearity cluster, [( iPr2-bimy)6Cu10S8Hg3] 6. The new N-heterocyclic carbene metal-chalcogenolate complexes 1, 2, 4, 5 and the ternary mixed-metal chalcogenolate complex 3 and cluster 6 have been characterized by multinuclear NMR spectroscopy (1H and 13C), elemental analysis and single-crystal X-ray diffraction. [ABSTRACT FROM AUTHOR]

The first examples of gold(I) trimethylsilylchalcogenolate complexes were synthesized and their reactivity showcased in the preparation of a novel gold-copper-sulfur cluster [Au 4 Cu 4 S 4 (dppm) 2 ] (dppm=bis(diphenylphosphino)methane). The unprecedented structural chemistry of this compound gives rise to interesting optoelectronic properties, including long-lived orange luminescence in the solid state. Through time-dependent density functional theory calculations, this emission is shown to originate from ligand-to-metal charge transfer facilitated by Au⋅⋅⋅Cu metallophilic bonding., (© 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

As a part of efforts to prepare new "metallachalcogenolate" precursors and develop their chemistry for the formation of ternary mixed-metal chalcogenide nanoclusters, two sets of thermally stable, N-heterocyclic carbene metal-chalcogenolate complexes of the general formula [(IPr)Ag-ESiMe3] (IPr=1,3-bis(2,6-diisopropylphenyl)imidazolin-2-ylidene; E=S, 1; Se, 2) and [(iPr2-bimy)Cu-ESiMe3]2 (iPr2-bimy=1,3-diisopropylbenzimidazolin-2-ylidene; E=S, 4; Se, 5) are reported. These are prepared from the reaction between the corresponding carbene metal acetate, [(IPr)AgOAc] and [(iPr-bimy)CuOAc] respectively, and E(SiMe3 )2 at low temperature. The reaction of [(IPr)Ag-ESiMe3] 1 with mercury(II) acetate affords the heterometallic complex [{(IPr)AgS}2Hg] 3 containing two (IPr)Ag-S(-) fragments bonded to a central Hg(II), representing a mixed mercury-silver sulfide complex. The reaction of [(iPr2-bimy)Cu-SSiMe3]2, which contains a smaller N-heterocyclic-carbene, with mercuric(II) acetate affords the high nuclearity cluster, [(iPr2-bimy)6Cu10S8Hg3]6. The new N-heterocyclic carbene metal-chalcogenolate complexes 1, 2, 4, 5 and the ternary mixed-metal chalcogenolate complex 3 and cluster 6 have been characterized by multinuclear NMR spectroscopy ((1)H and (13)C), elemental analysis and single-crystal X-ray diffraction., (© 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)