Preparation and decomposition of gold(I) hydrazido complexes: gold cluster formation

Visalakshi, R.; Wu, Zhidan; Yang, Yi; Sharp, Paul R.

doi:10.1021/ja00030a084

Cited by 48 publications

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“…(1) Scherbaum, F.; Grohmann phosphine imines, 40,41 hydrazines, [42][43][44] and hydroxylamines. 45 Monoaurated ammonium cations also have been detected which show that stepwise substitution of the protons in the ammonium cation NH 4 + by [(L)Au] + cations is possible, 21,46,47 thus corroborating the isolobal principle 3,48 which predicts structure and bonding analogies between H + and [(L)Au] + .…”

Section: Introductionmentioning

confidence: 99%

The Elusive Structures of Pentakis[(triphenylphosphine)gold]ammonium(2+) Bis[tetrafluoroborate(1−)]

et al. 2000

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[Pentakis[(triphenylphosphine)gold(I)]ammonium(2+)] bis[(tetrafluoroborate)(1-)] was prepared from [tetrakis[(triphenylphosphine)gold(I)]-ammonium(1+)] [tetrafluoroborate(1-)] and [(triphenylphosphine)gold(I)] tetrafluoroborate in hexamethyl phosphoric triamide and tetrahydrofuran at 20 degrees C in 53% yield and crystallized from dichloromethane as the new solvate [[(Ph3P)Au]5N]3 [BF4]6 [CH2Cl2]4. The crystal structure of this product has been determined by single-crystal X-ray methods [monoclinic, P2(1/n), a = 34.200(3), b = 15.285(1), c = 53.127(3) A, beta = 107.262(2) degrees, V = 26521(3) A3, Z = 12, at 153 K]. The lattice contains three independent trinuclear dications that have no crystallographically imposed symmetry and are mutually similar in their molecular structure. The geometry of the [Au5N] core with pentacoordinate nitrogen atoms is intermediate between trigonal-bipyramidal and square pyramidal with severe distortions to minimize the Au-Au distances along some of the edges of the polyhedra. The three structures are thus different from that found previously in the tetrahydrofuran solvate [[(Ph3P)-Au]5N](BF4)2(C4H8O)2, where the geometry of the same trinuclear dication is closer to the trigonal-bipyramidal reference model. The new results are discussed in the light of the structures of tetra(gold)ammonium cations in salts of the type [[(Ph3P)Au]4N]+X- and of related tetra-, penta-, and hexacoordinate poly(gold)phosphonium, -arsonium, -sulfonium, and -selenonium cations.

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Section: Introductionmentioning

confidence: 99%

The Elusive Structures of Pentakis[(triphenylphosphine)gold]ammonium(2+) Bis[tetrafluoroborate(1−)]

et al. 2000

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“…The first is the cationic [Au 6 (PPh 3 ) 6 ] 2þ cluster, prepared through decomposition of the hydrazido complex [R 2 NN(AuPPh 3 ) 3 ]BF 4 [8] or through degradation of the cluster [Au 8 (PPh 3 ) 8 ] 2þ in the presence of [Ag(CN) 2 ] À [9]. The first is the cationic [Au 6 (PPh 3 ) 6 ] 2þ cluster, prepared through decomposition of the hydrazido complex [R 2 NN(AuPPh 3 ) 3 ]BF 4 [8] or through degradation of the cluster [Au 8 (PPh 3 ) 8 ] 2þ in the presence of [Ag(CN) 2 ] À [9].…”

Section: Synthesis and Structural Characterization Of Phosphine-stabimentioning

confidence: 99%

“…In these studies the XPS, TGA and elemental analysis confirm that the undecagold core is preserved during the exchange reaction between triphenylphosphine and the thiol ligands. Finally, the XPS spectrum of this cluster exhibits three peaks corresponding to three peripheral gold atoms each bonded to a thiol ligand, seven peripheral gold atoms each bonded to PPh 3 ligands and one central gold atom (Figure 3 (SR) [8][9][10][11] 1) 20 eq of HSR, 55ºC The molecular structure of this cluster has been determined via a synchrotron radiation source and it displays an incomplete icosahedral skeleton with an almost C 3v symmetry axis.…”

Section: Synthesis and Structural Characterization Of Phosphine-stabimentioning

confidence: 99%

“…These Au 38 (PhCH 2 CH 2 S) 24 MPCs undergo place exchange reactions with other thiolate ligands or even PPh 3 ligand [71,72]. Recently, the undecagold cluster [A 11 (PPh 3 ) 8 Cl 3 ] has been used as a precursor of the Au 25 (SG) 18 cluster, providing a large-scale synthesis of this thiolate-protected gold cluster [75]. Thus, the use of w-functionalized thiols with a phosphine stabilized [Au 11 (PPh 3 ) 8 Cl 3 ] cluster or 1.5 nm triphenylphosphine-stabilized gold nanoparticles is a versatile approach since a wide variety of technologically important functional groups can be employed [73,74] (Scheme 3.9).…”

Section: Monolayer Protected Clustersmentioning

confidence: 99%

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Gold Nanomaterials

Fernndez¹,

Monge²

2008

Modern Supramolecular Gold Chemistry

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The strong development of activities related to the nanoscience and nanotechnology of gold has led to a great number of publications in this research field. In this chapter, we will focus on the synthesis of cluster aggregates displaying gold-gold bonds and the formation of gold nanoparticles. Special consideration will be given to the chemical bottom-up approach for the synthesis of gold nanomaterials using different methods.Section 3.2 describes the synthesis and structure of small gold clusters taking into account the number of gold atoms, the reducing agents employed and the stabilizing ligands used, such as phosphines, arsines, thiols, and so on. Section 3.3 discusses the synthesis and properties of large size gold clusters such as the Au 55 cluster series. Finally, in Section 3.4, we describe the synthesis of gold nanoparticles and the development of new nanomaterials based on gold nanoparticles using bottom-up chemical methods and give a short summary of their properties and applications. Molecular Gold ClustersHerein we describe the synthesis and characterization of small-size homonuclear gold cluster compounds with a nuclearity ranging from 3 to 39 gold atoms. These types of clusters are usually characterized through definitive structural techniques such as single-crystal X-ray diffraction, enabling in-depth study of the structural arrangements found in the solid state.This section is divided into two main subsections. The first describes the synthesis and characterization of phosphine-stabilized gold clusters. The second focuses on the synthesis and characterization of thiol-stabilized gold clusters and the study of other stabilizers such as arsines or boranes are described.The first tetranuclear gold clusters were reported in the 1980s, namely [Au 4 (PPh 3 ) 4 (m-I) 2 ] (Au-Au distances from 2.649(1) to 2.828(1) Å) [1] and [Au 4 (dppm) 3 (m 3 -I)I] (Au-Au distances from 2.724(1) to 2.947(1) Å) [2]. The first cluster was prepared through a degradation reaction of the nonanuclear cluster [Au 9 (PPh 3 ) 8 ] 3þ , while the second was obtained by reaction of the already mentioned [Au 4 (PPh 3 ) 4 (m-I) 2 ] cluster and one equivalent of dppm ligand. Both structures display distorted tetrahedral cores of gold atoms with the iodine atoms bridging two different gold centers in the first case and three gold centers in the second (Scheme 3.1).In the 1990s, tetranuclear gold clusters [Au 4 (PR 3 ) 4 ]BF 4 (R ¼ t Bu [3] and (C 6 H 3 Me-1,3,5) [4]) were reported. Both clusters are synthesized from the corresponding oxonium salts [O{Au(PR 3 )] 3 ]BF 4 and [HO{Au(PR 3 )] 2 ]BF 4 (R ¼ t Bu and (C 6 H 3 Me-1,3,5)). In both clusters, X-ray diffraction analysis showed that gold atoms form a regular tetrahedron and each phosphine ligand is coordinated to one gold center (Scheme 3.2).The latest examples of tetranuclear gold clusters are based on phosphinocarborane ligands, namely [Au 4 {(PPh 2 ) 2 C 2 B 9 H 10 } 2 {P(4-OMeC 6 H 4 ) 3 } 2 ] [5] and, more recently, [Au 4 {(PPh 2 ) 2 C 2 B 9 H 10 } 2 {PPh 3 } 2 ] [6]. The firs...

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“…[1][2][3][4][5][6][7][8][9][10][11][12][13] These catalysts complete numerous different types of reactions including those requiring Lewis acid activation of alkynes and alkenes, insertion into the C À H bond of alkynes, oxidation of alkenes or alcohols, and reductive silylation of alcohols. [14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30][31][32] Asymmetric versions of homogeneous gold catalysts have been reported including recent work with chiral ligands or with chiral counterions that greatly increased the enantioselectivities of gold catalysts. [33][34][35][36][37][38] As the reactions and applications of gold catalysts increase, the need to decrease the loadings of gold and increase their turnovers has become an important consideration requiring further development.…”

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confidence: 99%

Extended Lifetimes of Gold(III) Chloride Catalysts using Copper(II) Chloride and 2,2,6,6‐Tetramethylpiperidine 1‐Oxyl (TEMPO)

2011

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The turnovers of a gold(III) chloride catalyst were increased by 3,300% with the addition of several equivalents of 2,2,6,6‐tetramethylpiperidine 1‐oxyl (TEMPO) and catalytic amounts of copper(II) chloride. A three‐component coupling reaction between piperidine, phenylacetylene, and benzaldehyde yielded a propargylic amine in quantitative conversions and isolated yields when gold(III) chloride was added in catalytic amounts, but the gold catalyst decomposed and had little to no reactivity when a second set of piperidine, phenylacetylene, and benzaldehyde was added after the reaction was complete. Thus, only one cycle was possible with gold(III) chloride. The addition of TEMPO and copper(II) chloride to reactions with gold(III) chloride maintained the catalytic activity of gold for up to 33 cycles. This result demonstrates a new way to greatly increase the turnovers of a gold(III) chloride catalyst with the addition of inexpensive, commercially available reagents.

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Preparation and decomposition of gold(I) hydrazido complexes: gold cluster formation

Cited by 48 publications

References 1 publication

The Elusive Structures of Pentakis[(triphenylphosphine)gold]ammonium(2+) Bis[tetrafluoroborate(1−)]

The Elusive Structures of Pentakis[(triphenylphosphine)gold]ammonium(2+) Bis[tetrafluoroborate(1−)]

Gold Nanomaterials

Extended Lifetimes of Gold(III) Chloride Catalysts using Copper(II) Chloride and 2,2,6,6‐Tetramethylpiperidine 1‐Oxyl (TEMPO)

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