Evidence for Au(I)…Au(I) Interactions in a Sterically Congested Environment: Two-Coordinate Gold(I) Halide Phosphine Complexes

2004 ◽  
Vol 57 (3) ◽  
pp. 213 ◽  
Author(s):  
Raymond C. Bott ◽  
Peter C. Healy ◽  
Graham Smith

Two-coordinate tris(2-methylphenyl)phosphine and tris(4-methylphenyl)phosphinegold(I) halide complexes, [AuP(otol)3X], [AuP(ptol)3X], where X = Cl, Br, and I, have been crystallized from dimethylformamide and characterized by single-crystal X-ray structure determinations. The P(otol)3 structures comprise an isomorphous series distinct from the previously published chloride, crystallizing with two independent molecules in the asymmetric unit in the space group Pbca, with a ≈ 20.0, b ≈ 28.0, c ≈ 14.0 Å. The molecules associate to form dimers through a back-to-back sextuple phenyl embrace (6PE). The P(ptol)3 complexes are isomorphous with the previously published chloride, crystallizing with two independent molecules in the unit cell in the space group P21/c, with a ≈ 10.0, b ≈ 22.0, c ≈ 19.5 Å, β ≈ 99°. The molecules associate through edge-to-face interactions along the direction of the a-axis. Preparation of the chloride by anodic dissolution of gold in an acetonitrile solution of the ligand and aqueous HCl yields a new polymorph, crystallizing in the space group Aba2, with a 19.738(2), b 11.813(3), c 17.645(1) Å. Despite the bulkiness of the phosphine ligand, this form of [AuP(ptol)3Cl] exhibits a short intermolecular Au…Au contact distance of 3.375(1) Å, indicative of a significant aurophilic interaction. The ranges for the Au—P, Au—Cl, Au—Br, Au—I bond lengths and P—Au—X bond angles in the series are: 2.201(3)–2.265(4), 2.255(3)–2.290(4), 2.388(2)–2.411(2), 2.542(1)–2.556(2) Å, and 173.2(2)–179.6(1)° respectively.

2011 ◽  
Vol 66 (7) ◽  
pp. 705-710
Author(s):  
Peter G. Jones ◽  
Ina Dix ◽  
Mihaela Negru ◽  
Dieter Schollmeyer

Pseudo-ortho- or 4,16-diformyl[2.2]paracyclophane (1) and two polymorphs of pseudo-meta- or 4,13-diformyl[2.2]paracyclophane (2) all display the usual features of [2.2]paracyclophane strain (lengthened C-C bonds and widened C-C(sp3)-C angles in the bridges, narrower sp2 ring angles at the bridgehead atoms, and flattened boat conformations of the rings). All bulk samples were racemates. Polymorph 2a crystallizes in space group P21/n with one molecule in a general position, whereas 2b crystallizes in space group C2 with two independent molecules, each with crystallographic twofold symmetry. All three molecules of 2 are different rotamers with respect to the formyl groups; in 2a one is endo and one exo to the neighbouring bridge, whereas in 2b both formyls are exo in one molecule and endo in the other. In all compounds, the packing patterns are preponderantly associated with C-H・ ・ ・O contacts. In 1 the molecules are connected to form tubes parallel to the short a axis. 2a consists of two interconnected layer structures. One is parallel to (100) and involves chains of molecules parallel to [01̄1]; the other is parallel to (001) and involves chains of molecules parallel to the b axis. 2b consists of two hexagonal layers, one for each independent molecule, parallel to (001). One layer contains bifurcated (C-H・ ・ ・ )2O systems, whereas the single H・ ・ ・O interactions in the other are long and markedly bent.


1991 ◽  
Vol 46 (8) ◽  
pp. 992-998 ◽  
Author(s):  
Henning von Arnim ◽  
Werner Massa ◽  
Alfred Zinn ◽  
Kurt Dehnicke

Orange crystals of (PPh4)2[Pd2Cl4(NH2)2] have been prepared by the reaction of (PPh4)2[Pd2Cl6] with N,N,N′-tris(trimethylsilyl)benzamidine in boiling acetonitrile in the presence of water, and orange brown crystals of PPh4{[Ph—C(NH2)(NH)]PdCl3} by the reaction of the amidinato complex PPh4[Ph—C(NSiMe3)2PdCl2] with HCl gas in acetonitrile solution. The complexes were characterized by IR spectroscopy as well as by X-ray structure determinations.(PPh4)2[Pd2Cl4(NH2)2] · CH2Cl2: Space group PĪ, Z = 1, 2784 observed unique reflections, R = 0.043. Lattice dimensions at —60 °C: a = 1053.3(4), b = 1081.1(4), c = 1249.2(4) pm, α = 102.90(2)°, β = 110.44(2)°, γ = 102.23(2)°. The compound consists of PPh4+ ions and centrosymmetric anions [Pd2Cl4(NH2)2]2- with bridging chlorine atoms and terminal amido groups.PPh4{[Ph—C(NH2)(NH)]PdCl3} -CH3CN: Space group C2/c, Z = 8, 1183 observed unique reflections, R = 0.033. Lattice dimensions at —60 °C: a = 3106.7(6), b = 1059.0(1), c = 1818.0(4) pm, β = 90.98(2)°. The compound consists of PPh4+ ions, [Ph—C(NH2)(NH)PdCl3]-ions, and included CH3CN molecules. In the anion the benzamidine ligand is bound via the nitrogen atom of the imido group.


1992 ◽  
Vol 45 (7) ◽  
pp. 1155 ◽  
Author(s):  
GA Bowmaker ◽  
D Camp ◽  
RD Hart ◽  
PC Healy ◽  
BW Skelton ◽  
...  

The 1 : 1 complexes of the substituted triphenylphosphine ligands mesityldiphenylphosphine and dimesitylphenylphosphine with copper(1) chloride, bromide and iodide have been the subject of single-crystal X-ray structure determinations at 295 K. All six complexes crystallize as air-stable dimeric molecules, [(PPh2Mes)CuX]2 and [ (PPhMes2)CUX]2 with each copper atom in a distorted trigonal PCuX2. coordination environment. Crystals of [(PPh2Mes)CuCl]2 (1) are monoclinic, P21/n, a 9.961(3), b 18.687(6), c 11.009(7) Ǻ, β 114.63(4)°; R was 0.049 for 2450 'observed' reflections. [(PPh2Mes)CuBrI2 (2) is monoclinic, P21/n, a 9.939(2), b 18.832(6), c 11.238(6) Ǻ, β 115.36(3)°; R was 0.046 for 1803 'observed' reflections. [(PPh2Mes)CuI]2.4/3 C6H6 (3) is rhornbohedral, R3, a 36.877(8), c 9.047(5) A; R was 0.039 for 2537 'observed' reflections. Crystals of [(PPhMes2)CuCl]2.2MeCN (4) are triclinic, Pi, a 15.783(7), b 9.570(4), c 8.914(4) Ǻ, α 72.43(3), β 76.37(3), γ 74.03(3)°; R was 0.045 for 3341 'observed' reflections. [(PPhMes2)CuBr]2.3C6H6 (5) is monoclinic, C2/c, a 9.694(6), b 30.15(2), c 20.66(2) Ǻ, β 98.00(7)°; R was 0.047 for 2117 'observed' reflections. [(PPhMes2)CuI]2.2MeCN (6) is orthorhombic, PP1nb, a 11.694(8), b 14.77(1), c 29.76(3) Ǻ; R was 0.049 for 3447 'observed' reflections. Cu-P bond lengths are: 2.196(2) A (1); 2.198(3) Ǻ (2); 2.222(5) and 2.226(5) Ǻ (3); 2.202(1) Ǻ (4); 2.197(3) A (5); 2.201(4) and 2.264(5) Ǻ (6). The geometries of the LCuX2 and CuX2Cu units are compared with data reported for other monomeric and dimeric compounds for both phosphorus- and nitrogen-based ligands L.


1975 ◽  
Vol 53 (23) ◽  
pp. 3596-3598 ◽  
Author(s):  
François Brisse ◽  
Aviva Battat ◽  
Jean-Claude Richer ◽  
Pierre Mazerolles ◽  
Alfreda Faucher

1,1-Dimethyl-1-germa (and-1-sila) -6,7-cycloundecanediol (C12H26O2Ge and C12H26O2Si) are isostructural as established by their X-ray powder patterns. The dimensions of the triclinic cells are as follows: for the silicon derivative, a = 10.53, b = 12.45, and c = 12.43 Å, α = 81.5°, β = 67.0°, and γ = 76.3°; for the germanium derivative, a = 10.56, b = 12.50, and c = 12.58 Å, α = 82.1°, β = 67.8°, and γ = 76.1°. If the space group is [Formula: see text] there will be two independent molecules in each asymmetric unit.


2002 ◽  
Vol 57 (8) ◽  
pp. 914-921 ◽  
Author(s):  
P. G. Jones ◽  
J. Ossowski ◽  
P. Kus

N,N′-Dibutyl-terephthaldiamide (1), N,N′-dihexyl-terephthaldiamide (2), N,N′-di(tert-butyl)- terephthaldiamide (3), N,N,N′,N′-tetrabutyl-terephthaldiamide (4), 1,1′-terephthaloylbis- pyrrolidine (5), 1,1′-terephthaloyl-bis-piperidine (6), and 4,4′-terephthaloyl-bis-morpholine (7) have been synthesised and physicochemically characterised. The X-ray structure determinations reveal imposed inversion symmetry for compounds 1-6; compound 3 has two independent molecules with inversion symmetry in the asymmetric unit. Compounds 1-3 form classical hydrogen bonds of the type N-H···O=C, leading to a ribbon-like arrangement of molecules (1 and 2) or a layer structure (3). Compound 3 also displays a very short C-H···O interaction, a type of hydrogen bond that is also observed in compounds 4-7, which lack classical donors; thereby compounds 4-6 form layer structures and 7 a complex threedimensional network.


1975 ◽  
Vol 30 (5-6) ◽  
pp. 462-464 ◽  
Author(s):  
R. Haegele ◽  
W. Verscharen ◽  
D. Babel

The parameters of complete X-ray structure determinations are given for the fluoridesRb2NaFeF6 and Rb2KFeF6 (cubic), Cs2NaCrF6 and Cs2NaFeF6 (hexagonal-rhom-bohedral) and Cs2LiGaF6 (hexagonal). Space group and lattice constants of the monoclinic cyanides Cs2BFe(CN)6 (B = Na, K, Rb) are reported as well.


1988 ◽  
Vol 43 (10) ◽  
pp. 1279-1284 ◽  
Author(s):  
Mervat El Essawi ◽  
H Gosmann ◽  
D Fenske ◽  
F Schmock ◽  
K Dehnicke

Triphenylmethylphosphonium nitrite and formate have been prepared by the reaction of [PPh3Me]I with silver nitrite, and lead formate, respectively, in aqueous solutions. [PPh3Me]NO2 (1) forms pale yellow crystals, and [PPh3Me]HCO2·H2O (2) forms white crystals. Both compounds are soluble in water, ethanol, and dichloromethane. In moist air 2 is hydrated to yield [PPh3Me]HCO2·2H2O (3). The compounds were characterized by their IR spectra, 1 and 2 also by X-ray crystal structure determinations.[PPh3Me]NO2 (1): space group P21/n, Z = 4, 2088 independent observed reflexions, R = 0.062. Lattice dimensions (20 °C): a = 914.7(3), b = 1887.5(9), c = 1080.0(4) pm, β = 110.29(3)°. The compound consists of PPh3Me+ ions and NO2- anions with bond lengths of 114.2(6) pm and a bond angle of 124.1(7)°. [PPh3Me]HCO2·H2O (2): space group P21/n, Z = 4, 2973 independent observed reflexions, R = 0.069. Lattice dimensions (-20 °C): a = 931(2), b = 1558(3), c = 1281(2) pm, β = 105.9(1)°. The compound consists of PPh3Me+ ions and formate anions which form centrosymmetric dimeric units [HCO2·H2O]22- through hydrogen bridges of the water molecules. Bond lengths CO 122.4(4) and 120.9(4) pm. bond angle OCO 129.9(4)°.


2012 ◽  
Vol 68 (8) ◽  
pp. o2358-o2358 ◽  
Author(s):  
María-Guadalupe Hernández Linares ◽  
Gabriel Guerrero-Luna ◽  
Sylvain Bernès ◽  
Marcos Flores-Alamo ◽  
María A. Fernández-Herrera

Diosgenone [(20S,22R,25R)-spirost-4-en-3-one, C27H40O3] has been proposed as a new therapeutic alternative for the treatment of malaria. The first X-ray structure report for diosgenone was by Piroet al.[(2002).Z. Naturforsch. Teil C,57, 947–950] in the space groupP21(Z′ = 2). We now report a new polymorph in the same space group, with two molecules in the asymmetric unit. Both molecules have similar conformations, characterized by a skewed envelopeAring, which contains the C=C bond conjugated with the ketone functionality at C3. The dimorphism results from a modification of the relative orientation of the molecules in the asymmetric unit: two independent molecules were arranged antiparallel in the Piro report, while they are parallel in the present determination.


1988 ◽  
Vol 43 (3) ◽  
pp. 323-327 ◽  
Author(s):  
H. Schumann ◽  
J. Loebel ◽  
D. van der Helm ◽  
M. B. Hossain

The title compound (1) is obtained as brownish crystals by reaction of HOCl3 with NaC5Me5 in tetrahydrofuran. The structure of 1, which has two slightly different independent molecules per asymmetric unit, has been elucidated by X-ray analysis. The crystals are triclinic with a = 1686.2(8) pm, b = 1816(1) pm, c = 846.5(4) pm, α = 92.02(7)°, β = 92.47(9)°, γ = 63.21(5)°, space group P1̄, D(calcd) = 1.560 g/cm3, and R = 0.0286, for 6219 observed reflections with I > 3σ(I).


1985 ◽  
Vol 40 (2) ◽  
pp. 251-257 ◽  
Author(s):  
Siegfried Pohl ◽  
Wolfgang Saak ◽  
Bernt Krebs

Abstract The compounds [(C6H5)4As]2 TeCl4 (1), [(C2H5)4 N]2 TeBr4 · CH3CN (2), and [(C2H5)4N]2TeI4 (3) were prepared by the reaction of Te, X2 , and excess (C2H5)4NX (X = Br, I) in acetonitrile solution or by heating of [(C6H5)4 As]2TeCl6 , Te, and (C6H5)4 ASCl for several hours in the same solvent.The structures of 1-3 were determined from single crystal X-ray data.1 crystallizes in the monoclinic space group P21/n with a = 1061.8(2), b = 1614.2(3), c = 1341.7(3) pm, β = 94.21° and Z = 2; 2: tetragonal, P4/mmm, a = 1039.7(2), c = 690.5(1), Z = 1; 3: tetragonal, I4/mmm, a = 1061.7(2), c = 1342.8(4), Z = 2. In 1-3 Te(II) exhibits a square planar coordination. The Te -CI, Te -Br, and Te-I bond lengths were found to be 260.7 (mean), 275.3, and 298.5 pm, respectively.


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