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The synthesis, structure, and phosphorescence properties of two families of triphosphine-supported Au(I)–Ag(I) heteronuclear alkynyl cluster complexes with unprecedented Au2Ag2 and Au8Ag4 cluster structures are described. The phosphorescence emission over the whole visible light region was systematically tuned through modification of the electronic effects in aromatic acetylide ligands to attain bright phosphorescence with different luminescent colors. Introduction of electron-withdrawing CF3 to phenylacetylides results in the emission spectral blue-shift, while it shows progressive red-shift upon introducing electron-donating But, OMe, or NMe2. As demonstrated from both experimental and theoretical studies, the phosphorescence arises primarily from 3LLCT/3IL and Au2Ag2/Au8Ag4 cluster-centered 3[d→p] transitions.

A triphosphine-stabilized Ag16Cu9 heterometallic alkynyl cluster complex was prepared by the reaction of polymeric silver(I) (4-tert-butylphenyl)acetylide with a copper(I) dpepp (dpepp = bis(2-(diphenylphosphino)ethyl)phenylphosphine) complex and characterized by X-ray crystallography. This Ag16Cu9 heterometallic alkynyl complex exhibits an unprecedented structural topology stabilized by three auxiliary triphosphine ligands. The (4-tert-butylphenyl)acetylide exhibits five types of asymmetric bonding modes, including μ-η1, μ-η1(σ):η2(π), μ3-η1, μ3-η1(σ):η1(σ):η2(π), and η1-μ4. This Ag16Cu9 complex exhibits visible to near-infrared luminescence in both fluid CH2Cl2 solution and the solid state.

Reaction of cis- or trans-Pt(PPh3)2Cl2 (PPh3 = triphenylphosphine) with 5-[2-(trimethylsilyl)-1-ethynyl]-2,2′-bipyridine (bpyC≡CSiMe3) gave cis-Pt(PPh3)2(C≡Cbpy)2 (1) or trans-Pt(PPh3)2(C≡bpy)2 (5). Incorporating 1 or 5 with Ln(hfac)3(H2O)2 (hfac = hexafluoroacetylacetonate) induced formation of the corresponding cis- or trans-PtLn2 heterotrinuclear complexes cis-Pt(PPh3)2{(C≡Cbpy)Ln(hfac)3}2 (Ln = Nd 2, Eu 3, Yb 4) or geometrical isomers trans-Pt(PPh3)2{(C≡Cbpy)Ln(hfac)3}2 (Ln = Nd 6, Eu 7, Yb 8). As verified through 31P NMR characterization as well as determination of the structures of 1, 4, and 8 by X-ray crystallography, the cis- or trans-arranged forms around PtII centers remain unchanged in both solutions and solid states without thermal or light-induced isomerization during the reactions. With excitation at 360 < λex < 450 nm, which is the absorption region of metal-perturbed π→π* (C≡C) transitions and dπ(Pt)→π*(C≡Cbpy) MLCT transition, sensitized lanthanide luminescence occurs with a microsecond r...

The preparation and characterization of the mononuclear complexes cis-Pt(dppe)(C⋮CPhtpy)2 (1) and cis-Pt(dppp)(C⋮CPhtpy)2 (5) (dppe = 1,2-bis(diphenylphosphino)ethane, dppp = 1,3-bis(diphenylphosphino)propane, HC⋮CPhtpy = 4‘-(4-ethynylphenyl)-2,2‘:6‘,2‘ ‘-terpyridine) and the corresponding PtLn2 (Ln = Eu, Nd, Yb) heterotrinuclear complexes by incorporating the precursor 1 or 5 with Ln(hfac)3(H2O)2 are described. 1 and 5 exhibit intense, long-lived room-temperature phosphorescence, originating probably from an admixture of 3ILCT (π → π*(C⋮Cphtpy)) and 3MLCT (d(Pt) → π*(C⋮CPhtpy)) triplet states, which qualifies them as favorable energy donors to facilitate Pt → Ln energy transfer in the corresponding PtLn2 heterotrinuclear complexes. As anticipated, sensitized lanthanide luminescence in PtLn2 heterotrinuclear complexes is attained through efficient energy transfer from PtII alkynyl chromophore based 3MLCT and 3ILCT triplet states.

Reaction of the polymeric silver ferrocenylacetylide (AgC⋮CFc)n with [M2(Ph2PNHPPh2)2(MeCN)2]2+ (M = Cu, Ag, Au) gave rise to the isolation of rhombic dodecahedral AgI8MI6 cage complexes together with the unusual 1,2,5-azadiphospholium product [FcCCH(Ph2PNPPh2)](BF4) by the cyclic addition of FcC⋮C to Ph2PNHPPh2. Distinct redox wave splitting occurs in the AgI8CuI6 cage complex with ΔE1/2 = 0.15 V due to successive oxidation of the Fc groups, induced probably by electronic interactions between iron centers in the ferrocenylacetylides.

A series of PtM, PtM2, and Pt2M3 (M = Cu, Ag, Au) heteronuclear alkynyl complexes, synthesized by reaction of the tetraalkynylplatinate(II) complexes [Pt(C⋮CR)4]2- with [M2(μ-dppm)2]2+ (dppm = bis(diphenylphosphino)methane), were characterized by elemental analyses, ESI-MS, 1H and 31P NMR spectroscopy, and X-ray crystallography for 5−13. The PtII and MI centers are linked doubly and singly by dppm in the PtM and PtM2 complexes, respectively. The Pt2Ag3 complex 13 is composed of two PtAg units associated with another Ag center by acetylide η2 (π) coordination. Strong Pt−M bonding interactions are operative, in view of their rather short distances (2.7−3.0 A). Compounds 1−13 emit strongly in the solid state at 298 and 77 K with lifetimes in the microsecond range, indicating spin-forbidden triplet excited states. They also exhibit moderate photoluminescence in degassed dichloromethane at 298 K. The emission energy in the solid state decreases with an increase in the electron-donating ability of the R substit...

A series of C4−C10 bridged Ru2II,II complexes [{(Phtpy)(PPh3)2Ru}2(C⋮C−(CHCH)m−C⋮C)]2+ (m = 0, 1, 2, 3) were prepared by reaction of [(Phtpy)(PPh3)2Ru(acetone)]2+ with Me3Si−C⋮C−(CHCH)m−C⋮C−SiMe3 in the presence of potassium fluoride. Oxidation of the Ru2II,II complexes by 1 equiv of ferrocenium hexafluorophosphate gave the stable Ru2II,III mixed-valence complexes [{(Phtpy)(PPh3)2Ru}2(C⋮C−(CHCH)m−C⋮C)]3+ when m = 0, 1, or 2. These complexes were all characterized by microanalyses, ESI-MS, 1H and 31P NMR, IR, and UV−vis−NIR spectroscopy, cyclic and differential pulse voltammetry, and X-ray crystallography for compound [1](PF6)2. The wave separations ΔE1/2 (E1/2A − E1/2B) due to stepwise oxidation of two RuII into RuIII are 0.610, 0.260, 0.165, and

A series of RuII2FeII2 heterotetranuclear σ-acetylide complexes [{Cp(dppf)Ru}2(C⋮C−R−C⋮C)] (dppf = 1,1‘-bis(diphenylphosphino)ferrocene, R = 0, 1; 1,4-benzenediyl, 2; 1,4-naphthalenediyl, 3; 9,10-anthracenediyl, 4) were prepared and characterized by elemental analyses, ES-MS spectrometry, IR, 1H and 31P NMR, and UV−vis−NIR spectroscopy, and cyclic and differential pulse voltammetry. Reaction of 1 with [Cu(MeCN)4](ClO4) gave RuII2FeII2CuI2 heterohexanuclear compound [{Cp(dppf)Ru}2{Cu(MeCN)}2(C⋮C−C⋮C)](ClO4)2 [5(ClO4)2] through π-bonding of the acetylides to CuI centers. The structures of 1 and 5(ClO4)(SbF6) were determined by X-ray crystallography. Chemical oxidation of 1, 3, and 4 with an equivalent of ferrocenium hexafluorophosphate gave one-electron-oxidized species [{Cp(dppf)Ru}2(C⋮C−R−C⋮C)](PF6) [R = 0, 1a(PF6); 1,4-naphthalenediyl, 3a(PF6); 9,10-anthracenediyl, 4a(PF6)] with Ru2II,III mixed valence. Electrochemical and visible−infrared spectral studies revealed that the electronic delocalization depe...

Reactions between the acetate-bridged diruthenium complex Ru2(O2CCH3)4Cl and the cyanide-containing organometallic complex Cp(dppe)FeCN or Cp(PPh3)2RuCN brought about the isolation of the cyanide-l...

Crystallographic characterization of the metastable alkynyl complexes [Au6Ag13(μ-dppm)3(μ3-η1-C⋮CC6H4R-4)14]5+ (R = H (1a), CH3 (2a), But (3a)) is described. Photolysis of the green Au6Ag13 alkynyl...