H. Behm

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.

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.

Synthesis, characterization and x-ray molecular and crystal structure of Tc(NS)Cl3(Me2PhP)(Me2PhPO)-a first example of mixed phosphine/phosphine oxide coordination

The reaction of TcNCl 2 (Me 2 PhP) 3 with excess S 2 Cl 2 yields trichloro(dimethylphenylphosphine)- (dimethylphenylphosphine oxide)thionitrosyltechnetium(II), Tc(NS)Cl 3 (Me 2 PhP)(Me 2 PhPO), whereas an equimolar reaction mixture yields dichlorotris (dimethylphenylphosphine)thionitrosyltechnetium- (I), Tc(NS)Cl 2 (Me 2 PhP) 3 . Tc(NS)Cl 3 (Me 2 PhP)(Me 2 PhPO) (formula weight 543.74) crystallizes in the orthorhombic space group P 2 1 2 1 2 1 with a = 10.513(1), b =14.274(2) and c =15.187(2) A ( Z = 4). The phosphine oxide ligand is arranged in trans position to the linearly coordinated thionitrosyl group.

Crystal and molecular structure of diaquabis(thiocyanato-N)bis(5-methyl-[1,2,4]triazolo[1,5-a]pyridine-N3)cobalt(II), [Co(NCS)2(C6H6N4)2(H2O)2]

The X-ray crystal structure of the title compound, [Co(NCS)2(C6H6N4)2(H2O)2], has been determined. The crystals are monoclinic, space groupC2/c, with cell dimensionsa=15.6901(5),b=7.9248(10),c=16.1278(12) Å,β=94.4(8)°Vc=1999.44 Å3,Mr=479.18,Z=4,Dx=1.5918 Mg m3,Cu Kα radiation (graphite crystal monochromator, λ=1.54051 Å), μ(CuKα)=39.08 cm−1,F(000)=980.00 andT=290 K. Final conventionalR-factor=0.051, andRw=0.053 for 1430 “observed” reflections and 141 variables. The structure was solved using the programsPatsys andDirdif. The Co atom is octahedrally coordinated (CoN2O2N2 chromophore), with only the 5-methyl-[1,2,4]-triazolo[1,5-a]pyrimidine (5mtp) ligands in thetrans positions. The triazolo pyrimidine rings are planar and coordinated through their N(3) atoms. The H2O ligands are also H-bond donors to N(4) (intramolecularly) and to the S atoms of the NSC anions (intermolecularly).

Crystal and molecular structure of 1R,3S,5S,7R,10R-3,6,6,10,14-pentamethyltricyclo[10.3.0.05,7]pentadeca-11,14-diene-1,10-dihydroxy-2,13-dione (Japodagrol), C20H28O4

A new cytotoxic macrocyclic diterpenoid named Japodagrol, C20H28O4, has been isolated from the ornamental plantJatropha podagrica, family Euphorbiaceae, grown in Nigeria. The structure of the title compound, C20H28O4, was solved by X-ray analysis.Mr=332.44, monoclinic space groupC2,a=23.285(4),b=6.5105(12),c=12.505(3) Å,β=98.504(17),V=1874.8 Å3,Z=4,Dc=1.178 Mg/m3. CuKα radiation (graphite crystal monochromator, λ=1.54184 A),μ (CuKα)=6.13 cm−1,F(000)=720,T=290 K. Final conventionalR factor=0.035,Rw=0.038 for 3349 “observed” reflections. The structure was solved with the programDirdif. The 5-membered ring is closed to a half-chair form. The compound contains inter- and intramolecular hydrogen bonds.

Crystal and molecular structure of 1-vinyl-3-methyl-imidazolium iodide, C6H9N2I

The title compound crystallizes with two independent molecules in the unit cell. The two molecules arecis-trans isomers. Crystal data: orthorhombic, P212121,a=7.0417(6),b=9.5341(9),c=25.411(2) Å,Z=8. The crystal structure has been solved by automated Patterson methods and refined toR=0.024 for 1843 observed reflections.

Crystal and molecular structure of 1-methyl-2,3,5,6-tetraphenylpiperidin-4-ol, C30H29NO

The structure of the the title compound, C30H29NO, was determined by X-rays.Mr=419.57, triclinic, space groupP1,a=5.8922(12),b=8.5855(11),c=12.2216(20) Å,α=78.145(12)°,β=79.181(15)°, γ=76.108(14)°,Vc=581.1(1) Å3,Z=1,Dx=1.199 Mg m−3. CuKα radiation (graphite crystal monochromator, λ=1.54184 Å),μ(CuKα)=5.17 cm−1,T=290K. Final conventionalR-factor=0.039,Rw=0.042 for 2795 observed reflections and 377 variables. The structure was solved usingMultan andDirdif. With a view to determining the conformational preference of the piperidine ring when it is highly sustituted with a bulky group like the phenyl group, the present X-ray investigation was undertaken.