Klaus Angermaier

Crystal structures of chloro(trimethylphosphine) gold(I), chloro(tri-ipropylphosphine)gold(I) and bis(trimethylphosphine) gold(I) chloride

Abstract The crystal structures of chloro(trimethylphosphine)gold(I), chloro(tri- i propylphosphine)gold(I) and bis(trimethylphosphine)gold(I) chloride · 2CHCl 3 have been determined by single crystal X-ray diffraction studies. The monomeric units of the molecular complexes (Me 3 P)AuCl ( 1 ) and ( i Pr 3 P)AuCl ( 2 ) have linear PAuCl axes. However, the monomers of (Me 3 P)AuCl are aggregated to form a helical chain through fairly short alternating Au ⋯ Au contacts of 327.1(1), 335.6(1), and 338.6(1) pm and AuAuAu angles of 141.6(1), 141.8(1) and 141.9(1)°. By contrast, the monomers of compound 2 show no such Au ⋯ Au contacts in the lattice. This distinction between the two structures of the two analogous species is attributed to the different steric requirements of the phosphines. The crystals of bis(trimethylphosphine)gold (I) chloride ( 3 )·2CHCl 3 consist of layers of (Me 3 P) 2 AuCl complexes separated by layers of solvent molecules. The PAuP coordination is almost linear, with a chlorine atom at right angles (AuCl = 316.7(1) pm, ClAuP = 92.3(1)°).

(Phosphine)gold(I)-silyloxides and -silylthiolates

The gold siloxanes Me3PAuOSiMe3 (1) and Ph3PAuOSiPh3 (2) were prepared from the corresponding (phosphine)gold(I) chlorides and sodium silanolates in dichloromethane as colorless, stable, crystalline solids. The crystal structure of compound 1 (monoclinic, space group C2/c, Z = 8) has been determined by X-ray methods. The lattice contains centro-symmetrical dimers with short AuAu contacts (3.376(2) A). The SiAu angle is 121.0(4)°; the coordination geometry at the gold atom is close to linear. The hexaphenyl compound 2 is assumed to be a monomer like the methylpentaphenyl analog MePh2PAuOSiPh3, owing to steric effects. The thiosiloxane (silylthiolate) Ph3PAuSSiPh3 (3) was obtained from Ph3PAu(acac) and Ph3SiSH in CH2Cl2. It crystallizes in the monoclinic space group P21/n with Z = 4 molecules in the unit cell. The compound is a monomer in the crystal with a narrow angle at the sulfur atom (95.0(1)°) and a linear coordination geometry at the gold atom. Association is again prevented by steric effects.

9,10-DISILYLANTHRACENE ; SYNTHESIS, STRUCTURE AND FLUORESCENCE

Abstract For the preparation of the title compound, 9,10-dilithiumanthracene is treated with p -anisylchlorosilane to give 9,10-bis(p-anisylsily)anthracene ( 1 ) with high yields. The protodearylation of 1 with two equivalents of trific acid affords 9,10-bis(trifluoromethanesulfonatosily)anthracene, which can be converted into 9,10-disilylanthracene ( 2 ) using LiAlHP 4 . The crystal structures of 1 and 2 have been determined by single-crystal X-ray diffraction. Solutions of 1 and 2 in common organic solvents show a violet fluorescence. The fluorescence spectra are compared with data on anthracene and 9,10-disubstituted derivatives.

Calculated structures of SAu3+ and S(AuPH3)3+

Pseudopotential ab initio calculations on SAu3+ and S(AuPH3)3+ closely reproduce the experimental Au–S–Au angles of monomeric S(AuPR3)3+(PR3= PPh3, PPri3) if both correlation and relativistic effects are included.

LIGAND INFLUENCES ON THE SUPRAMOLECULAR CHEMISTRY OF SIMPLE GOLD(I) COMPLEXES : MONONUCLEAR (ISONITRILE)GOLD(I) COMPLEXES

Abstract A series of (isonitrile)gold(I) complexes has been synthesized: (MeNC)AuX (X = Cl la, I lc), (t-BuNC)AuBr 2b. (PhNC)AuX (X = Cl 3a. Br 3b. I 3c. SCN 3d), (MesNC)AuCl 4a [mes=mesityl], and (MeOC(O)CH2NC)AuX (X = Cl 5a. Br 5b. I 5c. SCN 5d). The chlorides were prepared by the reaction of (Me2S)AuCl with equimolar amounts (or with an excess) of the corresponding isonitrile. The bromides, iodides and thiocyanates were obtained from the reaction of (RNC)AuCl with K+X- (X = Br, I, SCN) in the two-phase system H2O/CH2CI2. The molecular and crystal structures of la. 2b. 3a-c, 4a, and 5a-c have been determined by X-ray diffraction methods. In the solid state the molecules are aggregated through short Au-Au contacts into dimers (4a and 5c), chains (la, 2b and 3a-c) or sheets (5a and 5b). The influence of the isonitrile and halide ligands on the type and strength of the intermolecular Au-A u contacts is discussed

Primary amines as nucleation centres for gold clustering, and the structural chemistry of polygold ammonium cations

Treatment of tert-butylamine and benzylamine with [Au(PR′3)]BF4 led to the monoauration products [(R′3P) AuNH2R]+BF4–(R′= Me, R = But1a; R′= Me, R = CH2Ph 1b; R′3= Ph2Me, R = But1c). The salts [{Au(PMe3)}3NR]+BF4–(R′= Me, R = But2a or CH2Ph 2b) derived from the same amines were obtained using the corresponding oxonium salt [{Au(PMe3)}3O]+BF4–. A diauration product [{Au(PMe3)}2NH(CH2Ph)]+BF4–3 was generated upon slow hydrolytic degradation of 2b in solution. Treatment of NH(SiMe3)2 with [{Au(PMe3)}3O]+BF4– afforded both the tris- and tetra-aurated ammonium salts, [{Au(PMe3)}3NSiMe3]+BF4–2c and [{Au(PMe3)}4N]+BF4–4, depending on the reaction conditions. The cation of 2c is one of the very rare examples of silylammonium species. Compound 4 was also obtained from the oxonium salt and ammonia. All compounds have been characterized through analytical and spectroscopic data. The crystal structure of 1a, 1c and 3 have been determined by X-Ray diffraction methods: 1c is a salt with monomeric gold ammonium cations, but 1a and 3 show supramolecular aggregation of the cations into dimers with short intercationic Au ⋯ Au contacts.

Synthesis, structure and complexes of a new bicyclic N,P-ligand derived from phosphatriazaadamantane

Reductive cleavage of the methylphosphoniatriazaadamantane cation by sodium in liquid ammonia affords the new bicyclic ligand (MeP)(CH2)5N2(NMe) whose structure has been determined from crystals of its 1 : 1 complex with AuCl.

Preparation and Structure of Poly(gold)telluronium Salts

Abstract Tris[(triphenylphosphine)gold(I)]telluronium tetrafluoroborate (1) was prepared from the corresponding oxonium salt and bis(t-butyldimethylsilyl)tellurium in dichloromethane at -78°C. The product forms yellow crystals, thermally stable to 125°C. It was identified by standard analytical and spectroscopic techniques, including a single crystal X-ray diffraction study. In the crystal lattice, the cations form tellurium-capped triangles of gold, which are associated into dimers through short intermolecular Au -Au contacts, resembling those in the corresponding sulfur and selenium compounds. - The reaction of (t-BuMe2Si)2Te with four equivalents of [(Ph3P)Au]BF4 in tetrahydrofuran at -78°C gives a tetranuclear compound, {[(Ph3P)Au]4Te}2+ 2 BF4- (2) which differs from 1 in its analytical and spectroscopic data. Its structure could not be determined, but it is assumed that the dications have a square pyramidal geometry

Polynuclear Gold Complexes of the Carbodiimide Unit [N=C=N]2-

Abstract The reaction of N,N′-bis(trimethylsilyl)carbodiimide with equimolar quantities of tris[(triphenylphosphine)gold]oxonium tetrafluoroborate in dichloromethane at -40°C gives high yields of a trinuclear complex {[(Ph3P)Au]2NCN[Au(PPh3)]}+ BF4-(1). According to variable temperature NMR data the cation is fluxional in solution with a rapid site exchange of the [(Ph3P)Au] units, but has an unsymmetrical (N,N,N′) low temperature ground state configuration. A single crystal X-ray diffraction study has shown that in the crystal lattice these cations are associated further into cyclic, hexanuclear dimers through two short head-to-tail Au-Au contacts (auriophilicity). Treatment of complex 1 with one equivalent of [(Ph3P)Au]+ BF4- in tetrahydrofuran affords a tetranuclear complex {[(Ph3P)Au]2NCN[Au(PPh3)]2}2+ 2BF4- (2). The ambient temperature NMR spectra of 2 suggest a fluxional, pseudo-symmetrical structure, but at low temperature a set of three 31P signals (1:2:3 intensity) indicates an aggregation into higher nuclearity species with non-equivalent [Au(PPh3)] units

Structural Investigation of Bis(isonitrile)gold(I) Complexes

The reaction of (MeNC)-, (PhNC)- and (MesNC)AuCl in tetrahydrofuran with an equimolar amount of the corresponding isonitrile ligand and one equivalent of Ag+X- (X-= BF- 4 or CF3SO-3) leads to the formation of the bis(isonitrile)gold(I) complexes (MeNC)2Au+ CF3SO-3(1), (PhNC)2Au+ BF-4 (2) and (MesNC)2Au+ BF-4(3). The crystal structures of 1, 2 and 3 have been determined. In compound 1 there are rod-like cations with a parallel packing into meandering puckered layers, in which the gold atoms have alternating Au-Au contacts of 3.611 and 3.624 Å. In complex 2 the cations form long double-paddles, with the two paddles at an angle of 77.5°. The individual cations are well separated and have no sub-van-der-Waals Au-Au contacts. The crystal structure of 3 is similar, but with a smaller dihedral angle between the planes of the two mesityl rings (56.0°)