K. I. Grandberg

Tris(triphenylphosphinegold)oxonium salts

Abstract The oxonium salts (Ph3PAu)3O+X- where X-  BF4-, CF3COO-, MnO4- have been prepared. These salts are formed from coordinatively unsaturated Ph3PAu+ cations in alkaline or acid media. An X-ray study of (Ph3PAu)3O+BF4- indicates that the oxonium ions are dimeric in the crystalline form. The fragment (Ph3PAu)3O has a pyramidal structure: the oxygen atom is outside the Au3 plane.

A new type of organogold compound

Organogold complexes of the type [R(AuPPh3)2]+BF−4 (I) containing a univalent gold atom and an AuAu fragment have been synthesised. They are formed by the interaction of RAuPPH3 with tetrafluoroboric acid or organomercury mercury compounds with CH3AuPPh3 and HBF4. Their structures have been identified through 1H NMR, 31P NMR, IR, UV (and X-ray for [C5H5 - FeC5C5H4(AuPPh3)2]+BF−4). When acted upon by nucleophilic reagents, the complexes liberate the cation AuPPh3+. Organometallic compounds promote an exchange of organic ligands.

Syntheses of organogold(1+) compounds by direct auration

Abstract Organogold(1+) compounds have been synthesized by direct auration of cyclopentadiene, cyanoacetic ester and malonitrile with (Ph 3 PAu) 3 O + BF 4 − . An X-ray structural study (λ Mo, 5062 reflections, R = 0.039) of bis(triphenylphosphinegold)malonitrile has been carried out (monoclinic, a = 12.055(6), b = 14.086(5), c = 20.466(12) A, β = 90.32(4)°, space group P 2 1 / c , Z = 4). The AuAu bond length is 2.912(1) A.

New organogold complexes: tetraphenylcyclopentadiene derivatives

Abstract Mono- and diaurated derivatives of tetraphenylcyclopentadiene, Ph4C5HAu-PPh3 and Ph4C5(AuPPh3)2, have been obtained by auration of tetraphenylcyclopentadiene with tris(triphenylphophinegold)oxonium tetrafluoroborate. Under the action of [Ph3,PAu]+BF4− both mono- and diaurated derivatives form the trinuclear cationic complex [Ph4C5(AuPPh3)3]+BF4−, which is converted into Ph4C5(AuPPh3)2 when treated with nucleophiles. The structure of Ph4C5HAuPPh3 and [Ph4C5(AuPPh3)3]+BF4− was established by IR, UV, PMR spectral and X-ray structural studies. Ph4C5HAuPPh3 has a CAu bond and additional coordination of Au with two neighboring carbon atoms of the five-membered ring; the structure is non-fluxional. The complex [Ph4C5(AuPPh3)3]+BF4− includes rather rare structural moieties: a three-membered carbometal cycle AuCAu , three gold atoms linked to each other, AuAuAu, and univalent gold coordinated with three carbon atoms of the Ph4C5 ring.

Redox properties of gold(I) compounds with organic ligands

Abstract Redox properties of numerous organogold compounds of different structures containing one, two, or three gold atoms are discussed on the basis of published reports and unpublished experimental electrochemical data obtained by the authors.

A tetranuclear organogold ferrocene derivative

Conclusions1.A dicationic organogold ferrocenyl complex containing four gold atoms, namely {[(Ph3PAu)2C5H4]2Fe}++(BF4−)2, was obtained by the action of triphenylphosphinegold tetrafluoroborate on 1,1′-bis(triphenylphosphinegold)ferrocene.2.The reaction of 1,1′-ferrocenyl-bis(triphenylphosphinegold) with HBF4 leads to cleavage of one C-Au bond and the formation of a binuclear cationic complex, namely, [C5H5 FeC5H4,(AuPPh3)2]+BF4−.

Cyanomethyl derivatives of gold

Conclusions1.Triphenylphosphine complexes of cyanomethylgold and dichlorocyanomethylgold have been synthesized.2.The chemical properties of aurated acetonitrile were typical for σ organogold compounds but aurated dichloroacetonitrile recalled the chemical behavior of complex gold halides3.The gold atom in the molecule of dichlorocyanomethyl (triphenylphosphine) gold has linear coordination, the bond lengths and angles were typical for organic complexes of univalent gold.

Gold-containing derivatives of cyclopropanecarboxylic acid amides

The interaction of substituted cyclopropanecarboxylic acid amides with [(Ph3PAu)3O]BF4 (I) has been studied. The reaction of I with cyclopropanecarboxylic acid p-nitroanilide leads to the gold derivative with the AuN bond, the small cycle being unaltered. The interactions between lithiated cyclopropanecarboxylic acid N,N-diethylamides and I afford the organogold derivatives of the amides with gold bonded to the carbon of the small cycle. The compounds obtained were characterized by IR, 1H and 13C NMR spectral data. An X-ray structural study of [triphenylphosphinegold(p-nitrophenyl)carbamoyl] cyclopropane and 1-triphenyl-phosphinegold-1-diethylcarbamoylcyclopropane was carried out. The interaction of lithiated derivatives of cyclopropanecarboxylic acid amides, in excess, with I gives unexpectedly stable anionic complexes of gold(I), (e.g. 1-diethylcarbamoylcyclopropyl)aurate. The potassium salt [(CH2CH2C)CONET2]2AuK is stable in air, and it was isolated after treatment of the lithium salt of bis(diethylcarbamoylcyclopropyl)aurate with potassium carbonate. Its dimeric nature was confirmed by an RDF study, the Au2K2 fragment being a distorted tetrahedron.

Reaction of gold compounds and diazomethane

1. We discovered the reaction of inserting the methylene group at the gold-chlorine bond to give chloromethyl (triphenylphosphine) gold. 2. The triphenylphosphine complexes of acetylacetonate-ferrocenyl-, and acetonylgold react with diazomethane to give vinyl(triphenylphosphine) gold. 3. The reaction of chloromethyl(triphenylphosphine)gold with KI and NaCN gave, respectively, triphenylphosphinegold iodide and methyltriphenylphosphonium dicyanoaurate.

The molecular structure of some amorphous organogold compounds studied by the radial distribution function method

Abstract The method of radial distribution functions (RDF) of atoms obtained from powder X-ray diffraction patterns has been applied to the determination of the molecular structure of a number of polynuclear organogold derivatives in the form of amorphous powders. The distances between Au atoms producing the strongest peaks on RDF have been measured directly. The modes of addition of (AuPPh3)+ cation to aurated phenylacetylene, acetonitrile and diaurated malonitrile and the presence of binuclear groupings (AuPPh3)2 with a direct AuAu bond, connected with cyclopentadienyl rings in tetragold derivatives of ferrocene, have been found.