Cyclic Trinuclear Gold(I) Clusters with N,N and Unusual C,C Mixed-Ligand Bridges.

Three crystalline trinuclear gold(I) clusters, [Aufy] (1), [Aufy] (2), and [Auy] (3), where f = N,N'-bis(2,6-dimethylphenyl)methanimidamidate and y = dimethylendiphenylphosphinate, exhibit bridges from the N,N-formamidinate and/or from the ylide anion ligand whose P-methylene groups chelate in an unusual fashion, where the chelate CPC unit is perpendicular to the trigonal plane of the metal atoms. Assemblies 1 and 2 are the first gold(I) trinuclear clusters featuring mixed-ligand bridges from different N,N and C,C donors; 3 is a previously unknown homoleptic ylide anion cyclic trinuclear assembly. Formamidinate bridges in 1 and 2 connect gold(I) atoms at aurophilic distances of 3.

Multinuclear copper(I) and silver(I) amidinate complexes: synthesis, luminescence, and CS2 insertion reactivity.

Dinuclear Cu(I) and Ag(I) complexes, Cu2[(2,6-Me2C6H3N)2C(H)]2, 1, Ag2[(2,6-Me2C6H3N)2C(H)]2, 2, Cu2[2,6-(i)Pr2C6H3N)2C(H)]2, 3, and Ag2[(2,6-(i)Pr2C6H3N)2C(H)]2, 4, were synthesized from reactions of [Cu(NCCH3)4][PF6] with Na[(2,6-R2C6H3N)2C(H)] and AgO2CCH3 with [Et3NH][(2,6-R2C6H3N2C(H)], R = Me, (i)Pr. Carbon disulfide was observed to insert into the metal-nitrogen bonds of 1 to produce Cu4[CS2(2,6-Me2C6H3NC(H)═NC6H3Me2)]4, 5, with a Cu4S8 core, which represents a rare transformation of dinuclear to tetranuclear species. Insertion is also observed with 2 and CS2, with the product likely being polymeric, 6.

Fine-tuning the luminescence and HOMO-LUMO energy levels in tetranuclear gold(I) fluorinated amidinate complexes.

Tetranuclear gold(I) fluorinated amidinate complexes have been synthesized and their photophysical properties and structures described. DFT calculations were carried out to illustrate how a minor change in the ligand resulted in a loss of emission in the perfluorophenyl amidinate complex compared with nonfluorinated phenyl amidinate complexes reported previously. The fluorinated complexes reported here [Au(ArN)(2)C(H)](4) (1, Ar = 4-FC(6)H(4); 2, 3,5-F(2)C(6)H(3); 3, 2,4,6-F(3)C(6)H(2); 4, 2,3,5,6-F(4)C(6)H) emit in the blue-green region at 470, 1, 478, 2, 508, 3, and 450 nm, 4, by excitation at ca.

A copper(I) homocubane collapses to a tetracapped tetrahedron upon hydride insertion.

The hydrido copper(I) and silver(I) clusters incorporating 1,1-dicyanoethylene-2,2-dithiolate (i-MNT) ligands are presented in this paper. Reactions of M(I) (M = Cu, Ag) salts, [Bu(4)N](2)[S(2)CC(CN)(2)], with the anion sources ([Bu(4)N][BH(4)] for H(-), [Bu(4)N][BD(4)] for D(-)) in an 8:6:1 molar ratio in THF produce octanuclear penta-anionic Cu(I)/Ag(I) clusters, [Bu(4)N](5)[M(8)(X){S(2)CC(CN)(2)}(6)] (M = Cu, X = H, 1(H); X = D, 1(D); M = Ag, X = H, 2(H); X = D, 2(D)). They can also be produced from the stoichiometric reaction of M(8)(i-MNT)(6)(4-) with the ammonium borohydride.

Synthesis and structure of a dinuclear gold(II) complex with terminal fluoride ligands.

The potential for reductive elimination of fluorine from dinuclear gold(II) for catalysis has prompted our efforts to synthesize a dinuclear gold(II) fluoride complex. This has been achieved with bis(2,6-dimethylphenyl)formamidinate bridging ligands. In order to obtain this product, it was necessary first to synthesize the corresponding dinuclear gold(II) nitrate, which reacts readily with KF in a metathesis reaction.

Halide and nitrite recognizing hexanuclear metallacycle copper(II) pyrazolates.

Halide-centered hexanuclear, anionic copper(II) pyrazolate complexes [trans-Cu(6)((3,5-CF(3))(2)pz)(6)(OH)(6)X](-), X = Cl, Br, I are isolated in a good yield from the redox reaction of the trinuclear copper(I) pyrazolate complex [μ-Cu(3)((3,5-CF(3))(2)pz)(3)] with a halide source such as PPh(3)AuCl or [Bu(4)N]X, X = Cl, Br, or I, in air. X-ray structures of the anion-centered hexanuclear complexes show that the six copper atoms are bridged by bis(3,5-trifluoromethyl)pyrazolate and hydroxyl ligands above and below the six copper atom plane. The anions are located at the center of the cavity and weakly bound to the six copper atoms in a μ(6)-arrangement, Cu-X = ~3.

A short, unsupported CuI...CuI interaction, 2.65 A, in a dinuclear guanidine chloride complex.

The reaction of CuCl with the neutral guanidine Hhpp ligand (1,3,4,6,7,8-hexahydropyrimido[1,2-a]pyrimidine) yields two crystalline polymorphs of the neutral dimer, bis(1,3,4,6,7,8-hexahydropyrimido[1,2-a]pyrimidine) dichloro-di-copper(I) with the shortest distance known for a bridging unsupported copper(I)-copper(I) interaction.

Mono and tetranuclear gold(I) complexes of tris(1-benzylimidazole-2-yl)phosphine.

The reaction of tris(1-benzylimidazole-2-yl)phosphine, (Bzim)(3)P, 1, with Ph(3)AsAuCl in 1:1 stoichiometric ratio produced (Bzim)(3)PAuCl, 2. The reaction of (Bzim)(3)PAuCl with NaAuCl(4) in 1:1 stoichiometry in dichloromethane gives an orange-yellow crystalline tetranuclear gold(I) cluster [{mu-N,N'-(Bzim)(3)PAuCl}(2)Au(2)][AuCl(2)][AuCl(4)], 3. Complex 4, [{mu-N,N'-(Bzim)(3)PAuCl}(2)Au(2)][AuCl(2)](2) is formed when the reaction stoichiometry of (Bzim)(3)PAuCl and AuCl(4)(-) is 2:1.

A monomeric gold(I) carbanion complex with an uncoordinated thioether: [2-(methylsulfanyl)phenyl](triphenylphosphine)gold(I).

The title compound, [Au(C7H7S)(C18H15P)], is conformationally chiral and crystallizes from benzene-hexane as individually enantiopure crystals. This mononuclear compound has the Au(I) atom linearly bound to a triphenylphosphine P atom and to a phenyl C atom of a 2-(methylsulfanyl)phenyl group. The angle at the Au(I) atom is 175.

The neutral cluster amminehexa-mu(2)-chlorido-mu(4)-oxido-tris(1,4,6-triazabicyclo[3.3.0]oct-4-ene)tetracopper(II).

The title compound, [Cu(4)Cl(6)O(C(5)H(9)N(3))(3)(NH(3))], is a neutral conformationally chiral cluster which crystallizes under the conditions described in this paper as a racemic conglomerate. It contains four Cu(II) atoms in a tetrahedral coordination with a central O atom lying on a crystallographic threefold axis. Six chloride anions bridge the four Cu(II) atoms.

Vapochromic behavior of {Ag2(Et2O)2[Au(C6F5)2]2}n with volatile organic compounds.

The vapochromic behaviors of {Ag2L2[Au(C6F5)2]2}n (L = Et2O (1), Me2CO (2), THF (3), CH3CN (4)) were studied. {Ag2L2[Au(C6F5)2]2}n (L = Et2O (1)) was synthesized by the reaction of [Bu4N][Au(C6F5)2] with AgOClO3 in 1:1 molar ratio in CH2Cl2/Et2O (1:2). 1 was used as starting material with THF to form {Ag2L2[Au(C6F5)2]2}n (L = THF (3)).

Dinuclear and tetranuclear gold-nitrogen complexes. Solvent influences on oxidation and nuclearity of gold guanidinate derivatives.

The sodium salt of the Hhpp ligand, Hhpp = 1,3,4,6,7,8-hexahydro-2H-pyrimido[1,2-a]pyrimidine, a 6,6 bicyclic, guanidine system, reacts with (THT)AuCl (THT = tetrahydrothiophene) in THF or CH2Cl2 to form the Au(II) complex, [Au2(hpp)2Cl2]. The Au(II) complex forms either by oxidation with solvents such as CH2Cl2 or disproportionation of Au(I) with concomitant Au(0) formation. The reaction in ethanol gives the colorless tetranuclear Au(I) complex, [Au4(hpp)4].

Oxidative addition of small molecules to a dinuclear Au(I) amidinate complex, Au2[(2,6-Me2Ph)2N2CH]2. Syntheses and characterization of Au(II) amidinate complexes including one which possesses Au(II)-oxygen bonds.

The dinuclear Au(I) amidinate complex Au2(2,6-Me2Ph-form)2 (1) is isolated in quantitative yield by the reaction of (THT)AuCl and the potassium salt of 2,6-Me2Ph-form in a 1:1 stoichiometric ratio. Various reagents such as Cl2, Br2, I2, CH3I, and benzoyl peroxide add to the dinuclear Au(I)amidinate complex Au2(2,6-Me2Ph-form)2 to form oxidative-addition Au(II) metal-metal-bonded complexes 2, 3, 4, 5, and 6. The Au(II) amidinate complexes are stable as solids at room temperature.

Self-assembly of a high-nuclearity chloride-centered copper(II) cluster. Structure and magnetic properties of [Au(PPh3)2][trans-Cu6(micro-OH)6[micro-(3,5-CF3)2pz]6Cl].

A chloride-centered hexanuclear copper(II) pyrazolate [Au(PPh3)2][trans-Cu6(micro-OH)6[micro-(3,5-CF3)2pz]6Cl] is isolated from the reaction of the trinuclear copper(I) pyrazolate [Cu3[micro-(CF3)2pz]3] with PPh3AuCl and Ph3P in moist air. The six copper atoms are bridged by pyrazolate and hydroxyl ligands, above and below the copper plane. The chloride anion exists at the center of the planar cavity formed by the copper atoms with Cu-Cl distances of 3.

Syntheses of mixed-ligand tetranuclear gold(I)-nitrogen clusters by ligand exchange reactions with the dinuclear gold(I) formamidinate complex Au(2)(2,6-Me2Ph-form)2.

The reaction of the sterically crowded dinuclear gold(I) amidinate complex Au2(2,6-Me2Ph-form)2, 1, with the less bulky bidentate nitrogen ligands results in the formation of tetranuclear gold(I) complexes. When the less bulky amidinate, K(4-MePh-form), A, was reacted with 1 in a 1:1 stoichiometric ratio, crystals containing equal amounts of the tetranuclear and dinuclear gold(I) aryl formamidinates, Au4(4-MePh-form)4 and Au2(2,6-Me2Ph-form)2, where 2,6-Me2Ph-form = B, were found in the same unit cell, 2 x 2THF: space group P, a = 10.794(11) A, b = 14.

Gold(I) and silver(I) mixed-metal trinuclear complexes: dimeric products from the reaction of gold(I) carbeniates or benzylimidazolates with silver(I) 3,5-diphenylpyrazolate.

Trinuclear mixed-metal gold-silver compounds are obtained by the reaction of gold(I) carbeniate [Au(mu-C(OEt)=NC6H4-p-CH3)]3, TR(carb), or gold(I) imidazolate [Au-mu-C,N-1-benzyl-2-imidazolate]3, TR(bzim), with silver(I) pyrazolate [Ag(mu-3,5-Ph2pz)]3. The crystalline products are mixed-ligand, mixed-metal dimeric products [Au(carb)Ag2(mu-3,5-Ph2pz)2], [Au2(carb)2Ag(mu-3,5-Ph2pz)].CH2Cl2, [Au(bzim)2Ag2(mu-3,5-Ph2pz)], and [Au2(bzim)2Ag(mu-3,5-Ph2pz)].

Mercury(II) cyanide coordination polymer with dinuclear gold(I) amidinate. Structure of the 2-D [Au2(2,6-Me2-formamidinate)2].2Hg(CN)2.2THF complex.

The dinuclear gold(I) amidinate complex [Au(2)(Me(2)-form)(2)], 1, (Me(2)-form = 2,6-Me(2)-formamidinate) reacts with Hg(CN)(2) to form a 2D structure, 1.2Hg(CN)(2).2THF.

External heavy-atom effect of gold in a supramolecular acid-base pi stack.

The nucleophilic trinuclear Au(I) ring complex Au3(p-tolN=COEt)3, 1, forms a sandwich adduct with the organic Lewis acid octafluoronaphthalene, C10F8. The 1.C10F8 adduct has a supramolecular structure consisting of columnar interleaved 1 ratio 1 stacks in which the Au3(p-tolN=COEt)3 pi-base molecules alternate with the octafluoronaphthalene pi-acid molecules with distances between the centroid of octafluoronaphthalene to the centroid of 1 of 3.

Mixed-metal triangular trinuclear complexes: dimers of gold-silver mixed-metal complexes from gold(I) carbeniates and silver(I) 3,5-diphenylpyrazolates.

Dimers of trinuclear mixed gold-silver compounds are obtained by the reaction of a gold(I) carbeniate, [Au(mu-C(OEt)=NC6H4-p-CH3)]3, with a silver(I) pyrazolate, [Ag(mu-3,5-Ph2pz)]3. The crystalline products are the mixed-metal species Au(carb)Ag2(mu-3,5-Ph2pz)2 and Au2(carb)2Ag(mu-3,5-Ph2pz)CCH2Cl2.

Novel metallamacrocyclic gold(I) thiolate cluster complex: structure and luminescence of [Au9(mu-dppm)4(mu-p-tc)6](PF6)3.

The structure of a novel metallamacrocyclic phosphine gold(I) thiolate cluster, [Au9(mu-dppm)4(mu-p-tc)6](PF6)3, where dppm = bis(diphenylphosphine)methane and p-tc = p-thiocresolate, is reported and shows AuAu attractions of approximately 3.0 A and gold(I) atoms linked to thiolate and phosphine ligands in distorted trigonal and nearly linear geometries.

The role of F-centers in catalysis by Au supported on MgO.

A correlation is found between the activity of Au clusters for the catalytic oxidation of CO and the concentration of F-centers in the surface of a MgO support. These results are consistent with recent theoretical results showing that F-centers in MgO serve to anchor Au clusters and control their charge state by partial transfer of charge from the substrate F-center to the Au cluster.

Synthesis and X-ray structures of dinuclear and trinuclear gold(I) and dinuclear gold(II) amidinate complexes.

The structures of the trinuclear gold(I), [Au(3)(2,6-Me(2)-form)(2)-(THT)Cl], the dinuclear [Au(2)(2,6-Me(2)-form)(2)], and the oxidative-addition product [Au(2)(2,6-Me(2)-form)(2)Cl(2)] formamidinate complexes are reported. The trinuclear complex is stable with gold-gold distances 3.01 and 3.

Synthesis, characterization, and luminescent properties of dinuclear gold(I) xanthate complexes: X-ray structure of [Au2(nBu-xanthate)2].

The synthesis and characterization of gold(I) complexes of butyl xanthate [Au(2)((n)()Bu-xanthate)(2)], 1, and ethyl xanthate [Au(2)(Et-xanthate)(2)], 2, are described. These complexes are readily prepared from the reaction between Au(THT)Cl (THT = tetrahydrothiophene) and the corresponding xanthate ligands as the potassium salts. The two xanthate complexes are characterized by (1)H NMR, IR, mass spectrometry, elemental analysis, and UV-vis techniques.

A detailed study of the vapochromic Behavior of [Tl[Au(C6Cl5)2]]n.

The linear-chain polymer [Tl[Au(C(6)Cl(5))(2)]](n), 1, reacts in the solid state and in solution with different volatile organic compounds such as tetrahydrofuran, acetone, tetrahydrothiophene, 2-fluoropyridine, acetonitrile, acetylacetone, and pyridine. Solid-state exposure of 1 to vapors of the above VOCs produces a selective and reversible change in its color that is perceptible to the human eye and even deeper under UV irradiation, allowing 1 to function as a sensor for these VOCs. Heating the samples exposed to the VOCs for a few minutes at 100 degrees C regenerates the original material without degradation, even after several exposure/heating cycles.

Synthesis and X-ray structures of silver and gold guanidinate-like complexes. A Au(II) complex with a 2.47 A Au-Au distance.

The structures of the tetranuclear silver(I), [Ag4(hpp)4], and the dinuclear gold(II), [Au2(hpp)2Cl2], (hpp = 1,3,4,6,7,8-hexahydro-pyrimido[1,2-a]pyrimidinate) guanidinate-like bases are reported and show a silver-silver distance of 2.8614(6) A and a gold-gold distance of 2.4752(9) A, the shortest Au-Au bond heretofore reported.