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Two heteroctanuclear Au4Ag4 cluster complexes of 4,5-diethynylacridin-9-one (H2L) were prepared through the self-assembly reactions of [Au(tht)2](CF3SO3), Ag(tht)(CF3SO3), H2L and PPh3 or PPh2Py (2-(diphenylphosphino)pyridine). The Au4Ag4 cluster consists of a [Au4L4]4− and four [Ag(PPh3)]+ or [Ag(PPh2Py)]+ units with Au4L4 framework exhibiting a twisted paper clip structure. In CH2Cl2 solutions at ambient temperature, both compounds show ligand fluorescence at ca. 463 nm as well as phosphorescence at 650 nm for 1 and 630 nm for 2 resulting from admixture of 3IL (intraligand) of L ligand, 3LMCT (from L ligand to Au4Ag4) and 3MC (metal-cluster) triplet states. Crystals or crystalline powders manifest bright yellow-green phosphorescence with vibronic-structured emission bands at 530 (568sh) nm for complex 1 and 536 (576sh) nm for complex 2. Upon mechanical grinding, yellow-green emission in the crystalline state is dramatically converted to red luminescence centered at ca. 610 nm with a drastic redshift of the emission after crystal packing is destroyed. [ABSTRACT FROM AUTHOR]

Two heteroctanuclear Au4Ag4 cluster complexes of 4,5-diethynylacridin-9-one (H2L) were prepared through the self-assembly reactions of [Au(tht)2](CF3SO3), Ag(tht)(CF3SO3), H2L and PPh3 or PPh2Py (2-(diphenylphosphino)pyridine). The Au4Ag4 cluster consists of a [Au4L4]4− and four [Ag(PPh3)]+ or [Ag(PPh2Py)]+ units with Au4L4 framework exhibiting a twisted paper clip structure. In CH2Cl2 solutions at ambient temperature, both compounds show ligand fluorescence at ca. 463 nm as well as phosphorescence at 650 nm for 1 and 630 nm for 2 resulting from admixture of 3IL (intraligand) of L ligand, 3LMCT (from L ligand to Au4Ag4) and 3MC (metal-cluster) triplet states. Crystals or crystalline powders manifest bright yellow-green phosphorescence with vibronic-structured emission bands at 530 (568sh) nm for complex 1 and 536 (576sh) nm for complex 2. Upon mechanical grinding, yellow-green emission in the crystalline state is dramatically converted to red luminescence centered at ca. 610 nm with a drastic redshift of the emission after crystal packing is destroyed.

Abstract. With the attempt to synthesize Nb‐enclosed germanium Zintl cluster ion in ethylenediamine (en) / toluene solution, the reaction of K4Ge9/Na4Ge9 with Nb(mes)2 (mes = mesitylene) gives unexpected 18‐crown‐6 cleavage product of [K14Na2(NbO2)2(C8H16O5)8](Ge5) (en)·solv in the form of very air‐sensitive, light‐brown, plate‐like crystals. This unique compound crystallizes in monoclinic Pn (No. 7) space group, the cleavage of crown linked the 14 potassium, 2 sodium, and 2 niobium atoms into the bulky 2+ charged cation, which balances the [Ge5]2– anion. This compound represents the rare example of heteronuclear metal alkoxide / Zintl ion hybrid. [ABSTRACT FROM AUTHOR]

Abstract: The reaction of Cp*Ir(CO)2 or CpIr(CO)2 with Ru3(CO)12 under a hydrogen atmosphere afforded the heterometallic clusters Cp*IrRu3(μ-H)2(CO)10 and CpIrRu3(μ-H)2(CO)10, respectively, in moderate yields. In the former reaction, the tetrahydrido cluster Cp*IrRu3(μ-H)4(CO)9 was also formed in trace amounts, although this cluster can be obtained in high yields by the hydrogenation of Cp*IrRu3(μ-H)2(CO)10; the Cp analogue was not obtainable. The reaction of Os3(μ-H)2(CO)10 with Cp*Ir(CO)2 afforded the osmium analogue Cp*IrOs3(μ-H)2(CO)10 in 70% yield, along with a trace amount of the pentanuclear cluster Cp*IrOs4(μ-H)2(CO)13. Hydrogenation of Cp*IrOs3(μ-H)2(CO)10 afforded Cp*IrOs3(μ-H)4(CO)9 in excellent yield. The reaction of Cp*Ir(CO)2 with Os3(CO)10(CH3CN)2 afforded the known trinuclear cluster Cp*IrOs2(CO)9 and the novel cluster Cp*IrOs3(CO)11. Solution-state NMR studies show that the hydrides in the iridium–ruthenium clusters are highly fluxional even at low temperatures while those in the iridium–osmium clusters are less so. [Copyright &y& Elsevier]

Abstract: The reactions of the heterometallic cluster Cp*IrOs3(μ-H)2(CO)10 with phosphines, isonitriles and pyridine under TMNO activation afforded the substitution products Cp*IrOs3(μ-H)2(CO)10−n L n (n =1, 2; L=PPh3, P(OMe)3, t BuNC, CyNC or py) in good yields. For the monosubstituted derivatives, the substitution site was exclusively at an osmium atom in an axial position for L=phosphine or phosphite. Spectroscopic evidence suggested the presence of isomers in solution for the PPh3 derivative. In contrast, for L=isonitrile, the ligand occupied an equatorial site. In the disubstituted derivatives, the group 15 ligands were coordinated to two different osmium atoms, one each at an axial and an equatorial site. The isomerism and fluxional behaviour of some of these clusters have also been examined. [Copyright &y& Elsevier]

The reaction of the di-gold cation [Au2(dppx)]2+ with the heptanuclear cluster dianion [Os7(CO)20]2− affords the mixed metal cluster [Os7(CO)20{Au2(dppx)}] (x=m ( 1), e ( 2), b ( 3)). On standing, in solution, this complex undergoes decarbonylation to give the cluster [Os7(CO)19{Au2(dppx)}] (x=m ( 4), e ( 5), b ( 6)). The complexes have been characterised spectroscopically, and an X-ray structure determination of the dppm derivative shows that it contains a metal core based on an Os7 edge-bridged bicapped tetrahedron with the two μ3-Au atoms capping adjacent triangular Os3 faces of the central tetrahedron. In an analogous reaction, the carbido anion [Os7(H)C(CO)19]− affords the neutral cluster [Os7C(CO)19{Au2(dppm)}] ( 7) when treated with [Au2(dppm)]2+ in the presence of base. [ABSTRACT FROM AUTHOR]

Addition of a THF solution prepared by stirring [CpRu(CO)2]2 over Na/Hg amalgam to a solution of the triplatinum cluster [Pt3(dppm)3(CO)][PF6]2 ( 1) in THF gives the heteronuclear cluster [Pt3(dppm)3{(μ4-Hg)–RuCp(CO)2}2] [PF6]2 ( 2) in 40% yield following chromatography. A single crystal X-ray study of 2 reveals structural parameters for the Pt3Hg2 molecular core that are consistent with those of other structurally characterized complexes of this type. 1H, 13C, and 31P NMR spectra of this complex indicate that the structure observed in the solid state is retained in solution. [ABSTRACT FROM AUTHOR]