Paul T. Beurskens

Heterometallic Pt-Au complexes with μ-3 S bridging. Syntheses and structures of Pt2 (PPh3)4(μ-SAuCl)2·2CH2Cl2 and Pt2(PPh3)4−(μ-S)(μ-SAuPPh3)NO3·0.5H2O

Abstract From Pt 2 (PPh 3 ) 4 (μ- S ) 2 ( I ) three heterometallic complexes can be prepared: Pt 2 (PPh 3 ) 4 (μ-SAuCl) 2 ( II ), (Pt 2 (PPh 3 ) 4 (μ-SAuPPh 3 ) 2 2+ ( III ) and Pt 2 (PPh 3 ) 4 - (μ-S)(μ-SAuPPh 3 ) + ( IV ). Their preparation and properties are described. The crystal and molecular structures of II and the nitrate of IV has been investigated by X-ray diffraction analysis. II crystallizes in the monoclinic space group P 2 1 / n , a = 18.359(2) b = 13.947(2), c = 14.588(2) A, β = 100.982(7)°, V = 3666.9 A 3 , M r = 2138.28, Z = 2, D c = 1.94 Mg/m 3 . Mo Kα radiation (graphite crystal monochromator, λ = 0.71069 A, μ(Mo Kλ)= 85.13 cm −1 , F (000) = 2032, T = 293 K. Final conventional R -factor = 0.039, Rw = 0.050 for 5084 unique reflections and 155 variables. IV crystallizes in the triclinic space group P 1 , a = 14.605(1), b = 15.989(2), c = 18.005(2) A, α = 101.144(8)°, β = 100.773(7)°, γ = 91.201(2)°, V = 4045.4 A 3 , M r = 2033.75, Z = 2, D c = 1.66 Mg/m 3 . Cu Kα radiation (graphite crystal monochromator, λ = 1.5418 A), μ(Cu Kα) = 116.45 cm −1 , F (000) = 1986, T = 293 K. Final conventional R -factor = 0.039 Rw = 0.051 for 8631 unique reflections and 297 variables. Both the structures were solved using SHELX84 and DIRDIF. The hinged square planar geometry of the parent I is kept in IV , where AuPPh 3 is bonded to one of the bridging S atoms. In II both bridging S atoms are bonded to AuCl and the hinging geometry is transformed into a nearly planar P 2 PtS 2 PtP 2 frame with the SAuCl vectors nearly perpendicular to it, one on each side of that plane. There are indications for weak AuPt bonding interactions. In IV and II the three-coordinated S-atoms have bond angles of about 90°. The structure of III is supported to be similar to II . Some reactions and interconversions of II , III and IV are described.

Reactions of gold–phosphine cluster compounds. Preparation and X-ray structure determination of octakis(triphenylphosphine)octa-gold bis(hexafluorophosphate)

[Au9L8]3+(L = PPh3) reacts with L to form [Au8L8]2+ and [AuL2]+; preliminary X-ray structural results are reported for [Au8L8][PF6]2.2CH2Cl2(1).

Self-association and self-assembly of molecular clips in solution and in the solid state

Clip molecules based on diphenylglycoluril form well-defined dimeric structures in chloroform solution and in the solid state. In solution the dimerization process is based on favourable π-π interactions and cavity filling effects. A combination of favourable π-π interactions and crystal packing forces determine the self-assembly of clips in the solid state. The geometry that the clip molecules adopt in solution and in a series of X-ray crystal structures is compared with favourable geometries predicted by molecular modelling calculations.

Preparation and X-ray structure determination of [pentakis{1,3-bis(diphenylphosphino)propane}] undecagoldtris(thiocyanate), [Au11{PPh2C3H6PPh2}5](SCN)3

The reaction of Au11[P(p-ClC6H4)3]7(SCN)3 with 1,3-bis(diphenylphosphino) propane (dppp) in methylene chloride leads to the formation of [Au11(dppp)5] (SCN)3 by a total substitution of the ligands. The compound crystallizes in the triclinic space groupP¯1,a=17.369,b=18.222,c=27.810 Å, α=104.00,β=105.25, γ=85.47°,Z=2. The structure was determined by a combination of Patterson, DIRDIF, and Fourier methods, with diffractometer data and refined by least-squares group refinement toR=0.081 for 2774 reflections.

Crystal and molecular structure of 3,5-bis(N,N-diethylimonium)-1,2,4-trithiolane-tetraiododi-μ-iododiinercurate(II)

The crystal and molecular structure of 3,5-bis(N,N-diethylimonium)-1,2,4-trithiolane-tetraiododi-μ-iododimercurate(II), (S3C2N2(C2H5)4)Hg2I6, has been determined from a single-crystal X-ray diffraction study. The monoclinic unit cell, space groupP21/c, witha = 12·574(3),b = 15·777(4),c = 14·560(4) Å, and β = 90·83(4) °, contains four formula-units. Three-dimensional intensity data were collected on an automatic diffractometer. Atomic parameters were refined by full-matrix least-squares methods to a conventionalR value of 0·05 for 1380 independent non-zero reflexions. The structure consists of (3,5-bis(N,N-diethyl-imonium)-1,2,4-trithiolane)2+ and Hg2I62− ions. The cation contains a five-membered ring, S-S-C-S-C, which can be formed by oxidation of dithiocarbamato and thiuramdisulfide complexes.

Copper(II) and zinc(II) co-ordination compounds of tridentate bis(benzimidazole)pyridine ligands. Crystal and molecular structures of bis[2,6-bis(1′-methylbenzimidazol-2′-yl)pyridine]copper(II) diperchlorate monohydrate and (acetonitrile)[2,6-bis(benzimidazol-2′-yl)pyridine](perchlorato)copper(II) perchlorate

Compounds are described of general formulae Cu(L1)X2, Cu(L1)2X2, Cu(L2)X2, and Cu(L2)2X2 with L1= 2,6-bis(benzimidazol-2′-yl)pyridine, L2= 2,6-bis(1′-methylbenzimidazol-2′-yl)pyridine, and X = Cl, Br, or ClO4. For comparison also a few zinc(II) halides were prepared and characterized. The compounds were structurally characterized by i.r., ligand-field, and e.s.r. spectra and for two representative cases [Cu(L1)(CH3CN)(ClO4)][ClO4](1) and [Cu(L2)2][ClO4]2·H2O (2) also by X-ray diffraction techniques. Compound (1) crystallizes in space group P21/c with a= 14.061(1), b= 20.638(1), c= 8.273(1)A, β= 101.119(8), and Z= 4; R= 0.0366 for 4 265 observed reflections with I > 2σ(I). Compound (2) crystallizes in space group P21/c with a= 8.4824(22), b= 29.1965(29), c= 16.7393(24)A, β= 95.836(17)°, and Z= 4; R= 0.062 for 3 165 observed reflections with I > 3σ(I). The structure of (1) consists of one tridentate chelating L1 ligand and CH3CN, co-ordinated in a square-planar geometry (Cu–N 1.96–2.03 A) with a perchlorato oxygen at 2.40 A, thereby completing a five-co-ordinate geometry. A sixth ligand at 2.8 A(from another perchlorate oxygen) is considered to be semico-ordinating. The structure of (2) consists of one tridentate and one bidentate L2, chelating in a five-co-ordinate geometry, again tetragonal pyramidal, with the apical ligand (Cu–N 2.51 A) coming from the bidentate chelating L2. The sixth donor atom, again from a perchlorate oxygen, at 2.70 A is considered to be semi-co-ordinating. Spectroscopic and magnetic data have been used to deduce structures for the other copper(II) compounds based on these two X-ray structures.

Crystal and molecular structure of triphenylphosphine (N,N-diethyldithiocarbamato)gold(I)

The crystal and molecular structure of triphenylphosphine (N,N-diethyldithio-carbamato) gold(I), (C6H5)3PAuSSCN(C2H5)2, has been determined by three-dimensional X-ray methods. The compound crystallizes in the monoclinic space groupP21/c witha = 13·547(1),b = 12·277(1),c = 14·013(1) Å, β = 90·81(1) ° andZ = 4. Three-dimensional intensity data were collected on an automatic diffracto-meter. Atomic parameters were refined by full-matrix least-squares methods to a conventionalR value of 0·04 for 2318 non-zero observed reflexions.In this complex the diethyldithiocarbamate moiety acts as a monodentate ligand, the double-bond distance being 1·68(1) Å and the bond involving the sulphur atom that is coordinated to the gold atom being 1·75(1) Å. The gold atom is linearly coordinated, the angle being 175·7(1) ° and the and distances being 2·338(3) and 2·251(3) Å, respectively.

Gold clusters: synthesis and characterization of [Au8(PPh3)7(CNR)]2+, [Au9(PPh36(CNR2]3+ and [Au11(PPH37(CNR)2O]2+ and their reactivity towards amines. The crystal structure of [Au11(PPh3)7(CN-i-Pr)2I](PF6)2

Abstract In the reactions of [Au8(PPh3)7]2+, [Au8(PPh3)8]2+ and [Au9(PPh3)8]3+ with RNC (R = isopropyl and t-butyl) in dichloromethane [Au8(PPh3)7CNR]2+ is initially, and is then converted into [Au9(PPh3)6(CNR)2]3+ via various intermediates. [Au9(PPh3)6(CNR)2]3+ reacts with I− at low temperature (−78°C) in methanol to yield [Au11(PPh3)7(CNR)2I]2+, but when the reaction is carried out at room temperature Au11 (PPh3)6(CNR)I3 is formed. The cluster compounds have been characterised by elemental analysis, 31P{1H} NMR, conductivity measurements, IR and 197Au Mossbauer spectroscopy. The reactions of the clusters with amines to form carbene clusters are very slow, and the reasons for this are considered. The structure of [Au11C134H112IN2P7](PF6 was determined by X-ray diffraction. Mr = 3796.39 cubic, space group 143d, a 37.955(12) A, V 54677.2 A3, Z = 16, Dc = 2.21 Mg m−3, Mo-Kα radiation (graphite crystal monochromator, λ 0.71069 A), μ(Mo-Kα) 125.2 cm−1, F(000) = 33510.3, T 293 K. Final conventional R-factor = 0.048, Rw = 0.062 ofr 1867 unique reflections and 198 variables. The Au-skeleton is the same as in Au11(PPh3)8I3 having C3v symmetry with one central and 10 peripheral Au atoms.

Synthesis and structural characterisation of [Pt3Au(μ2-CO)3(PPh3)5]NO3

The compound [Pt3Au(μ2-CO)3(PPh3)5]NO3 was formed as the main product of the reaction of AuPPh3NO3 with Pt(PPh3)3 and CO. Its structure was determined by X-ray diffraction, using Cu-Kα radiation with a graphite crystal monochromator; λ 1.54184 A, AuC93H75NO6P5Pt3 · 12 C4H10O, Mr = 2276.80, triclinic, space group P1−, a 15.256(2), b 14.422(2), c 21.663(3) A, α 93.138(9), β 91.823(9), γ 68.654(9)°, V 4432(3) A3, Z = 2, Dc 1.678 Mg/m3, μ(Cu-Kα) 131.8 cm−1, F(000) = 21.94, T 290 K. Final conventional R factor = 0.063, Rw = 0.078 for 11193 unique reflections and 322 variables. The structure was solved by automated Patterson methods. The metal cluster is a strongly distorted tetrahedron with one short (2.700(1) A) and two longer (2.906(1) A) PtAu distances. This bonding asymmetry is discussed in a comparison with known structures of similar 54 and 56 valence electron Pt3Au clusters.

Crystal and molecular structure of tetrapyridyl-copper(II)-bis-nitrato-bis-pyridine

The crystal and molecular structure of a pyridine complex of anhydrous copper(II)nitrate is described. The structure has been solved by vector search methods and refined by least-squares methods to R1=0.049 [I>2σ(I)]. The complex lies on a twofold axis parallel toa, and two solvent pyridine molecules lie on twofold axes parallel toc. The copper atom is coordinated by four pyridyl groups and two monodentate NO3 groups. Crystal data: C30H30N8O6Cu, orthorhombic, space group Pnna(52),a=14.446(7),b=12.154(5),c=16.881(4) Å,V=2964(2) Å3,Z=4.