Gold Carbonyl Research Articles

Zeolite NaY-supported gold complexes prepared from Au(CH3)2(C5H7O2): reactivity with carbon monoxide

Mononuclear gold complexes in zeolite NaY were synthesized from initially physisorbed Au(CH3)2(C5H7O2), and their reactions with CO in a flow system at 298 K and 760 Torr were investigated by infrared (IR) spectroscopy and mass spectral analysis of the effluent gases. CH4 and CO2 were formed as CO flowed through the sample either steadily or as successive pulses. The results are consistent with the inferences that (a) CO reacted with the supported gold to form gold carbonyls, (b) CH4 formed by reaction of methyl groups on gold with traces of H2O or hydroxyl groups on the zeolite and (c) CO on cationic gold reacted with traces of O2 and/or H2O to form CO2. In samples treated in steadily flowing CO, cationic gold was reduced to zerovalent gold, but the cationic gold in samples exposed to CO pulses was not reduced to zerovalent gold, although CO2 formed. Thus, CO adsorbed on cationic gold reacts to give CO2 in the absence of zerovalent gold, consistent with the inference that gold catalysts for CO oxidation need not contain zerovalent gold.

Structural Changes of the Gold−Support Interface during CO Oxidation Catalyzed by Mononuclear Gold Complexes Bonded to Zeolite NaY: Evidence from Time-Resolved X-ray Absorption Spectroscopy

Mononuclear gold complexes synthesized from AuIII(CH3)2(acac) in zeolite NaY were characterized by time-resolved X-ray absorption spectroscopy and infrared spectroscopy as they catalyzed CO oxidation at 298 K and 760 Torr in flow systems. Initial contact with a CO + O2 mixture led to the rapid formation of cationic gold complexes in which Au was bonded to approximately two zeolite O atoms, on average. Further contact with CO + O2 led to breaking of an Au-surface oxygen bond, giving a gold carbonyl anchored to approximately one O atom. The process was reversed in the absence of CO and O2.

Reactions of Gold Atoms and Small Clusters with CO: Infrared Spectroscopic and Theoretical Characterization of AunCO (n = 1−5) and Aun(CO)2 (n = 1, 2) in Solid Argon

Laser-ablated Au atoms have been co-deposited with CO molecules in solid argon to produce gold carbonyls. In addition to the previously reported Au(CO)n (n = 1, 2) and Au2(CO)2 molecules, small gold cluster monocarbonyls Au(n)CO (n = 2-5) are formed on sample annealing and characterized using infrared spectroscopy on the basis of the results of the isotopic substitution and CO concentration change and comparison with theoretical predictions. Of particular interest is that the mononuclear gold carbonyls, Au(CO)n (n = 1, 2), are favored under the experimental conditions of higher CO concentration and lower laser energy, whereas the yields of the gold cluster carbonyls, Au(n)CO (n = 2-5) and Au2(CO)2, remarkably increase with lower CO concentration and higher laser power. Density functional theory (DFT) calculations have been performed on these molecules and the corresponding small naked gold clusters. The identities of these gold carbonyls Au(n)CO (n = 1-5) and Au(n)(CO)2 (n = 1, 2) are confirmed by the good agreement between the experimental and calculated vibrational frequencies, relative absorption intensities, and isotopic shifts.

Formation of neutral and charged gold carbonyls on highly facetted gold nanostructures

We show that gold mono- and di-carbonyls are formed on gold field emitter tips during interaction with carbon monoxide gas at room temperature and in the presence of high electrostatic fields. The experiments are done in a time-of-flight atom probe to obtain mass spectra. The yield of monocarbonyl cations is about twice that of di-carbonyl ions. Density functional theory calculations are reported that explain the field stabilization of adsorbed carbonyls and the desorption yield of their cations.

Spectroscopic Characterization and Catalytic Application of Copper(I), Silver(I) and Gold(I) Carbonyl Cations in Strong Acids

Abstract Detailed IR, Raman, and NMR spectroscopic characterization has been carried out on the group 11 metal carbonyl cations, Cu(CO)n+ (n = 1, 2, 3, 4), Ag(CO)n+ (n = 1, 2, 3), and Au(CO)n+ (n = 1, 2), over a wide range of temperature and in a variety of strong acids. Based on these results their molecular structures were determined and their stabilities are compared and discussed. The active species have been determined to be Cu(CO)2+ (and Cu(CO)3+ as a minor species) instead of the previously assigned Cu(CO)3+, Ag(CO)+ instead of the previously assigned Ag(CO)2+, and Au(CO)2+, respectively, for the copper(I), silver(I) and gold(I) carbonyl cation-catalyzed carbonylation of olefins and alcohols in concentrated sulfuric acid. The reaction mechanism previously proposed for the metal carbonyl cation-catalyzed carbonylation has been modified to involve an olefin-metal-monocarbonyl (e.g., for Ag) or an olefin-metal-polycarbonyl (e.g., for Cu or Au) intermediate.

FTIR study of the electronic effects of CO adsorbed on gold nanoparticles supported on titania

Infrared spectra of CO adsorbed on nanometric gold particles supported on oxidised and reduced TiO 2 are reported. Depending on which pre-treatment is used different stretching bands related to gold carbonyls have been found. On calcined samples the predominant absorption band is at 2110–2120 cm −1, assigned to CO adsorbed linearly on nanometric gold metallic particles; on highly dehydrated, oxidised samples, a band at 2154 cm −1 is detected, ascribed to CO adsorbed on gold oxidised sites; on reduced samples some new bands in the frequency range 2050 to 1900 cm −1 are produced, assigned to CO adsorbed linearly and bridge-bonded on gold small clusters, perturbed by the negative charge produced in support reduction.

Towards an accurate gold carbonyl binding energy in AuCO+: Basis set convergence and a comparison between density functional and conventional methods

The binding energy of the ground-state AuCO+ molecule has been systematically investigated using quantum chemical methods such as various density functionals and correlated wave function based approaches like second order Mo/ller–Plesset perturbation and the coupled cluster ansatz with perturbative treatment of triple excitations. These were combined with a total of 14 relativistic effective core potential/valence and all-electron basis sets of increasing flexibility for gold and CO, respectively. Special emphasis is paid to the role of the basis set superposition error and the relevance of different ways to improve the one particle basis sets. A significant effect on the basis set superposition error is observed in the density functional schemes upon enlarging the valence basis sets.

ChemInform Abstract: A New Gold Catalyst: Formation of Gold(I) Carbonyl, (Au(CO)n)+ (n = 1, 2), in Sulfuric Acid and Its Application to Carbonylation of Olefins.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

A New Gold Catalyst: Formation of Gold(I) Carbonyl, [Au(CO)n]+ (n = 1, 2), in Sulfuric Acid and Its Application to Carbonylation of Olefins

A new gold catalyst, [Au(CO)n]+ (n = 1, 2), was synthesized by using a facile method from commercial gold(III) oxide, Au2O3, in concentrated H2SO4, which exhibits high catalytic activity for carbonylation of olefins. The gold monocarbonyl [Au(CO)]+ (1) and dicarbonyl [Au(CO)2]+ (2) cations coexist in H2SO4 solution, the former of which is much more stable than the latter. Both of the carbonyls show IR spectra of νCO (2194, 2208 cm-1) higher than that of free CO (2143 cm-1), indicating nonclassical (σ-only) gold−CO bonding. The gold carbonyl complexes coexisting in the concd H2SO4 solution exhibit a single resonance in the 13C NMR spectrum at 171 ppm at ambient temperature and pressure, reflecting rapid CO exchange between 1 (164 ppm) and 2 (175 ppm). The nonclassical gold(I) carbonyl solution worked as an excellent catalyst, with which olefins reacted with CO to give tert-carboxylic acids in good yields at room temperature and atmospheric pressure. The gold(I) dicarbonyl cation 2 was found to function as ...

Carbonyl Derivatives of Gold and Related Organometallics

The properties and reactions of simple gold carbonyls and related compounds are described and the bonding within the gold carbonyl molecules discussed in terms of bond dissociation enthalpies.

Coinage Metal Carbonyls and Isocyanides: Synthesis and Characterization of the Gold(I) Complexes [HB(3,5-(CF3)2Pz)3]AuCO and [HB(3,5-(CF3)2Pz)3]AuCNBut

Syntheses and IR spectroscopic and X-ray structural data for the gold(I) carbonyl and tert-butyl isocyanide complexes of the fluorinated tris(pyrazolyl)borate ligand [HB(3,5-(CF3)2Pz)3]- (where HB(3,5-(CF3)2Pz)3 = hydrotris(3,5-bis(trifluoromethyl)pyrazolyl)borate) are reported. The carbonyl complex [HB(3,5-(CF3)2Pz)3]AuCO (1) crystallizes in a triclinic unit cell, space group P1, with a = 8.3865(6) A, b = 8.6467(6) A, c = 19.009(2) A, α = 98.649(6)°, β = 93.043(7)°, γ = 117.446(6)°, V = 1197.5(2) A3, Z = 2, and R = 0.0372. The gold atom adopts a distorted tetrahedral geometry with an Au−C distance of 1.862(9) A. The 13C NMR spectrum of 1 displays a signal at δ 172.6 which corresponds to the carbonyl carbon. The νCO of 1 (2144 cm-1) is similar to that observed for the copper(I) analog. Metal−CO distances and the C−O stretching frequencies of the coinage metal carbonyl adducts of [HB(3,5-(CF3)2Pz)3]- follow the orders Ag > Au > Cu and Ag > Au ≥ Cu, respectively. Crystals of [HB(3,5-(CF3)2Pz)3]AuCNBut (2) ...

ChemInform Abstract: Novel Preparation of Gold(I) Carbonyls and Nitrosyls in NaY Zeolite and Their Catalytic Activity for NO Reduction with CO.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Novel preparation of gold(I) carbonyls and nitrosyls in NaY zeolite and their catalytic activity for NO reduction with CO

Intrazeolite AuI carbonyls (νCO= 2188 cm–1) and nitrosyls (νNO= 1820 cm–1) are formed by the reductive carbonylation of monolayer-dispersed AuCl3 in NaY cages, which exhibit catalytic activity for NO reduction with CO at 300–373 K.

Reaction of carbon monoxide in the super acid HSO3F-Au(SO3F)3, and the gold(I)bis(carbonyl)cation [Au(CO)2]+. Isolation and characterization of gold(I) carbonyl fluorosulfate, Au(CO)SO3F

Solutions of gold tris(fluorosulfate), Au(SO 3 F) 3 , in fluorosulfuric acid, HSO 3 F, behave as superacids and will dissolve up to ∼3.5 mol of CO/mol of Au(SO 3 F) 3 . During the CO uptake, Au(III) is reduced to Au(I), with Au + (solv) stabilized by CO to give the cation [(OC)Au(CO)] + (solv). The linear five-atom cation is characterized by its vibrational spectrum. The cation is stable in solution, but solvent removal in vacuo leads to the formation of a new gold(I) monocarbonyl derivative, Au(CO)SO 3 F, in quantitative yield as a white solid. Au(CO)SO 3 F is thermally stable up to 190°C

ChemInform Abstract: A Spectroscopic Study of the Reaction of Gold Atoms with CO in a Rotating Cryostat: Formation of a Variety of Gold Carbonyls.

AbstractIt is evidenced by EPR, FTIR, and UV/VIS spectroscopy that in the reaction of gold atoms with CO in inert hydrocarbon matrices at 77 K AuCO, Au(CO)2, a gold microcrystallite‐CO complex and, upon annealing, Au2(CO)4 are formed.

A spectroscopic study of the reaction of gold atoms with CO in a rotating cryostat: formation of a variety of gold carbonyls

Reaction of 197Au atoms with CO has been studied in inert hydrocarbon matrices in a rotating cryostat at 77 K by EPR, FTIR, and UV/visible spectroscopy. Au(CO)2 has been positively identified by FTIR spectroscopy and there is evidence for the formation of AuCO, a gold microcrystallite – CO complex and, upon annealing, Au2(CO)4. Electron paramagnetic resonance spectra are consistent with the formation of Au(CO) (OC) with the magnetic parameters: a13 = 325 MHz, a17 = 44 MHz, and g = 2.0014 and a gold microcrystallite – CO complex with g = 2.014. An intense broad absorption in the optical spectrum at 525 nm is assigned to Au(CO)2 and a less intense narrow band at 320 nm is assigned to AunCO. There is no spectroscopic evidence for the formation of Au(CO)3 in hydrocarbon matrices. Keywords: gold carbonyls, EPR, FTIR, UV/visible, matrix isolation.

Reactions of chloro(triphenylphosphine)gold(I) and [µ-l,2-bis(diphenylphosphine)ethane]-bis[bromogold(I)] with oxopurine bases. Molecular and crystal structure and bonding of (theophyllinato)(triphenylphosphine)gold(I)

The interaction of chloro(triphenylphosphine)gold(I) and [µ-1,2-bis(diphenylphosphine)ethane]bis[bromogold(I)] with oxopurine derivatives under basic conditions has been investigated. The resulting complexes, [Au(PPh33)L][{Au(PPh3)}2(µ-L)], [LAu(µ-dppe)AuL], and [Au(µ-dppe)-(µ-L)Au][L = purine anion, dppe = 1,2-bis(diphenylphosphine)ethane], containing one or two N-bonded gold(I) phosphine groups were characterized by means of 1H and 13C n.m.r. and i.r. spectroscopy. The crystal structure of the complex (theophyllinato)(triphenylphosphine)-gold(I) was determined by X-ray crystallography. The compound is triclinic, space group P, with a= 9.061(2), b= 9.762(4), c= 13.588(4)A, α= 71.30(2), β= 87.20(2), γ= 86.10(2)°, and Z= 2. The structure was refined anisotropically to R= 0.039 and R′= 0.044, on the basis of 5 150 observed reflections. The crystal contains discrete [Au(PPh3) L] molecules (L = theophyllinate anion) with no unusually close intermolecular contacts. The co-ordination of the gold atom is almost linear, P–Au–N(7) 176.1(2)° gold–nitrogen and gold–phosphorus bond distances of 2.047(7) and 2.231(2)A respectively. Other bond lengths and bond angles are normal. The Au ⋯ O(6) distance of 3.317(6)A indicates that there is no significant gold–carbonyl bonding.

ChemInform Abstract: Gold Carbonyl, Au(CO): Matrix Isolation ESR Study (generated in argon matrices by cocondensation of gold atoms and CO molecules).

Chemischer InformationsdienstVolume 17, Issue 7 Physical Organic Chemistry ChemInform Abstract: Gold Carbonyl, Au(CO): Matrix Isolation ESR Study (generated in argon matrices by cocondensation of gold atoms and CO molecules). P. H. KASAI, P. H. KASAISearch for more papers by this authorP. M. JONES, P. M. JONESSearch for more papers by this author P. H. KASAI, P. H. KASAISearch for more papers by this authorP. M. JONES, P. M. JONESSearch for more papers by this author First published: February 18, 1986 https://doi.org/10.1002/chin.198607047AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume17, Issue7February 18, 1986 RelatedInformation