Derivatives of Bis(diphenylphosphino)maleic Anhydride as Ligands in Polynuclear Gold(I) Complexes

Ligand-based control of nuclearity in (NHC)gold(I) sulfides

N-Heterocyclic carbene (NHC) ligands support gold(I) sulfide complexes of varying nuclearity and charge. For sterically undemanding ligands, gold(I) chlorides react with sulfide to form trigold μ₃-sulfido cations as the first observed products. The ligand IMes [1,3-bis(2,4,6-trimethylphenyl)imidazol-2-ylidene] supports a monomeric cation, whereas the ICy-(1,3-dicyclohexylimidazol-2-ylidene-) supported cation crystallises as a dimer linked through an aurophilic interaction. The more sterically demanding IDipp [1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene] supports a terminal hydrosulfide, a (μ-hydrosulfido)digold cation, and a μ₃-sulfido cation. Use of the expanded-ring NHC 7Dipp [1,3-bis(2,6-diisopropylphenyl)-4,5,6,7-tetrahydro-1,3-diazepin-2-ylidene] allows the isolation of a neutral digold sulfide.

Thermal Growth of Au-Fe Heterometallic Carbonyl Clusters Containing N-Heterocyclic Carbene and Phosphine Ligands

The thermal reactions of [NEt₄][Fe(CO)₄(AuNHC)] [NHC = IMes ([NEt₄][1]) or IPr ([NEt₄][2]); IMes = C₃N₂H₂(C₆H₂Me₃)₂; IPr = C₃N₂H₂(C₆H₃ⁱPr₂)₂], Fe(CO)₄(AuNHC)₂ [NHC = IMes (3) or IPr (4)], Fe(CO)₄(AuIMes)(AuIPr) (5), and Fe(CO)₄(AuNHC)(AuPPh₃) [NHC = IMes (6) or IPr (7)] were investigated in different solvents [CH₂Cl₂, CH₃CN, dimethylformamide, and dimethyl sulfoxide (dmso)] and at different temperatures (50-160 °C) in an attempt to obtain higher-nuclearity clusters. 1 and 2 completely decomposed in refluxing CH₂Cl₂, resulting in [Fe₂(CO)₈(AuNHC)]^- [NHC = IMes (10) or IPr (11)]. Traces of [Fe₃(CO)₁₀(CCH₃)]^- (12) were obtained as a side product. Conversely, 6 decomposed in refluxing CH₃CN, affording the new cluster [Au₃{Fe(CO)₄}₂(PPh₃)₂]^- (15). The relative stability of the two isomers found in the solid state structure of 15 was computationally investigated. 4 was very stable, and only after prolonged heating above 150 °C in dmso was limited decomposition observed, affording small amounts of [Fe₃S(CO)₉]^2- (9), [HFe(CO)₄]^- (16), and [Au₁₆S{Fe(CO)₄}₄(IPr)₄]ⁿ⁺ (17). A dicationic nature for 17 was proposed on the basis of density functional theory calculations. All of the other reactions examined led to species that were previously reported. The molecular structures of the new clusters 11, 12, 15, and 17 were determined by single-crystal X-ray diffraction as their [NEt₄][11]·1.5toluene, [Au(IMes)₂][15]·0.67CH₂Cl₂, [NEt₄][12], and [17][BF₄]_n·solvent salts, respectively.

Recent advances in the self-assembly of polynuclear metal–selenium and –tellurium compounds from 14–16 reagents

The use of reagents containing bonds between group 14 elements and Se or Te for the self-assembly of polynuclear metal–chalcogen compounds is covered. Background material is briefly reviewed and examples from the literature are highlighted from the period 2007–2017. Emphasis is placed on the different classes of 14–16 precursors and their application in the targeted synthesis of metal–chalcogen compounds. The unique properties arising from the combination of specific 14–16 precursors, metal atoms, and ancillary ligands are also described. Selected examples are chosen to underline the progress in (i) controlled synthesis of heterometallic (ternary) chalcogen clusters, (ii) chalcogen clusters with organic functionalized surfaces, and (iii) crystalline open-framework metal chalcogenides.

The coordination behavior of 2,3-bis(diphenylphosphino)maleic-N-phenylimide towards copper, silver, gold and palladium

In the coordination sphere of copper, silver and palladium 2,3-bis(diphenylphosphino)maleic-N-phenylimide can act as a radical, non-innocent ligand.

[Au12(PPh2)2S4(L2)4]2+ (L2 = 3,4-bis(diphenylphosphino)-2,5-bis(trimethylsilyloxy)furan): an Au12 unit protected by modified maleic anhydride phosphine ligands

The reaction of the bis(dichlorogold) complex of 2,3-bis(diphenylphosphino)maleic anhydride (L1) with S(SiMe₃)₂ in the presence of NaBPh₄ yields the ionic dodecanuclear cluster compound [Au₁₂(PPh₂)₂S₄(L2)₄](BPh₄)₂ (1). During the formation of 1, the initial ligand L1 is transformed into the doubly sylilated derivative, 3,4-bis(diphenylphosphino)-2,5-bis(trimethylsilyloxy)-furan (L2). The presence of bridging PPh₂ groups is a result of the transformation of L1 in the coordination sphere of Au(i). Compound 1 was characterized by single crystal X-ray diffraction and electrospray-ionization (ESI) mass spectrometry.

Bronze, silver and gold: functionalized group 11 organotin sulfide clusters

The synthesis, properties and reactivity of group 11 organotin sulfide clusters [(R(1)Sn)4(SnCl)2(MPPh3)2S8] (M = Cu, Ag), [(R(3)Sn)10Ag10S20], and [(R(1,3)Sn)2(AuPPh3)2S4] with covalently bound, carbonyl or hydrazine-terminated ligands R(1) = CMe2CH2C(Me)O or R(3) = CMe2CH2C(Me)NNH2 are reported.

Syntheses, structures and theoretical investigations of [Au10S2(PPh2)2(dppma2)4(dppma3)]·[Au6S2(dppma2)2(dppma3)]

The synthesis, crystal structure and theoretical studies of a high-nuclear gold(i) complex stabilized by bridging aromatic phosphane ligands are reported.