Crystal Structure and Ligand Mobility in Solution of cis-Dimethyl-bis(trimethylphosphine)gold(III) Complexes

2006 ◽  
Vol 61 (1) ◽  
pp. 1-5 ◽  
Author(s):  
Oliver Schuster ◽  
Hubert Schmidbaur

Complexes [Me2Au(PMe3)2]+ X− with X = I and ClO4 have been prepared by several conventional routes in good yields. The products are thermally stable and decompose above 130 °C with reductive elimination of ethane. The two salts crystallize as isomorphous orthorhombic dichloromethane solvates. The cations have the cis-configuration based on a crystallographically imposed C2v symmetry. Owing to the trans influence of the tertiary phosphine ligands the Au-C bonds are significantly shorter than in standard reference cases. The cations are stacked in pairs of columns running parallel to the c axis of the unit cell with the Me2Au units oriented in opposite directions and slightly interlocked. The anions are inserted into the pockets formed by the four Me3P groups of each pair of neighbouring cations in the same column. The large channels between the double columns are filled by the solvent molecules, which could be localized for the perchlorate salt, but were disordered and deficient in the iodide case.

1984 ◽  
Vol 62 (4) ◽  
pp. 755-762 ◽  
Author(s):  
Sara Ariel ◽  
David Dolphin ◽  
George Domazetis ◽  
Brian R. James ◽  
Tak W. Leung ◽  
...  

The ruthenium(II) porphyrin complex Ru(OEP)(PPh3)2 (OEP = the dianion of octaethylporphyrin) has been prepared from Ru(OEP)(CO)EtOH, and the X-ray crystal structure determined; as expected, the six-coordinate ruthenium is situated in the porphyrin plane and has two axial phosphine ligands. Synthesized also from the carbonyl(ethanol) precursors were the corresponding tris(p-methoxyphenyl)phosphine complex, and the Ru(TPP)L2 (TPP = the dianion of tetraphenylporphyrin, L = PPh3, P(p-CH3OC6H4)3, P″Bu3) and Ru(TPP)(CO)PPh3 complexes. Optical and 1H nmr data are presented for the complexes in solution. In some cases dissociation of a phosphine ligand to generate five-coordinate species occurs and this has been studied quantitatively in toluene at 20 °C for the Ru(OEP)L2 and Ru(TPP)L2 systems.


1989 ◽  
Vol 44 (5) ◽  
pp. 615-618 ◽  
Author(s):  
Evamarie Hey ◽  
S. Bruce Wild ◽  
Simon G. Bott ◽  
Jerry L. Atwood

The unit cell of (R*,R*)-(±)-[(η5-C5H5){1.2-C6H4(PMePh)2}Fe(PCl3)]Cl · 2 MeCN is orthorhombic, space group Pccn, with a = 1531.2(3). b = 2202.7(20). c = 1874.6(16) pm, and Z = 8. The salt crystallizes as a racemic compound with four pairs of asymmetric cations of opposite helicity and associated anions and solvent molecules in each unit cell.


2007 ◽  
Vol 63 (11) ◽  
pp. o4390-o4391 ◽  
Author(s):  
Marlon R. Lutz ◽  
Matthias Zeller ◽  
Daniel P. Becker

The title molecule, C27H24O9, was formed via a transannular electrophilic addition of a putative cyclotriveratrylene triketone and is made up of an anthrone and an isobenzofuranone ring that are connected via one C atom to form a spiro compound. The anthracene and isobenzofuranone ring systems of the spiro compound are both essentially planar and perpendicular to each other, with an angle of 89.90 (2)° between them. The rigid molecule crystallizes with large voids of 598.7 Å3, or 21.5% of the unit-cell volume, that are partially filled with unmodelled disordered solvent molecules. The voids stretch as infinite channels along the [101] direction. The packing of the structure is partially stabilized by a range of weak C—H...O hydrogen bonds and also by C—H...π interactions. No significant π–π interactions are present in the crystal structure.


Author(s):  
Joseph E. Meany ◽  
Deidra L. Gerlach ◽  
Elizabeth T. Papish ◽  
Stephen A. Woski

In the crystal of the title compound, C16H9BrN2O4·0.5C6H6, the molecules stack in a centrosymmetric unit cell in a 2:1 stoichiometry with co-crystallized benzene solvent molecules and interactviavarious weak interactions. This induces a geometry different from that predicted by theory, and is unique among the hemibiquinones heretofore reported.


IUCrData ◽  
2020 ◽  
Vol 6 (1) ◽  
Author(s):  
Arpita Saha ◽  
Clifford W. Padgett ◽  
Pierre LeMagueres ◽  
Kiana Moncur ◽  
Glory Onajobi

Our work in the area of synthesis of polynuclear manganese complexes and their magnetic properties led to the synthesis and crystallization of the title compound, [Mn7(C8H9NO3)4(C8H10NO3)4(C2H5O)2(C7H5O2)2O2]·8C2H5OH. Herein, we report the molecular and crystal structure of the title compound, which was synthesized by the reaction of Mn(C6H5COO)2 with pyridoxine (PNH2, C8H11NO3) followed by the addition of tetramethylammonium hydroxide (TMAOH). The core of this centrosymmetric complex is a cage-like structure consisting of six MnIII ions and one MnII ion bound together through Mn—O bonds. The compound crystallizes in hydrogen-bonded layers formed by O—H...N hydrogen bonds involving the aromatic amine group of the ligand PN2− with the neighboring O atoms from the PNH− ligand. The crystal structure has large voids present in which highly disordered solvent molecules (ethanol) sit. A solvent mask was calculated and 181 electrons were found in a volume of 843 Å3 in one void per triclinic unit cell. This is consistent with the presence of seven ethanol molecules per formula unit, which accounts for 182 electrons per unit cell. Additionally, one ethanol molecule was found to be ordered in the crystal.


2015 ◽  
Vol 71 (11) ◽  
pp. m207-m208 ◽  
Author(s):  
Souheyla Chetioui ◽  
Noudjoud Hamdouni ◽  
Djamil-Azzeddine Rouag ◽  
Salah Eddine Bouaoud ◽  
Hocine Merazig

The title complex, [Cu(C17H13N2O2)2], crystallizes with two independent molecules in the asymmetric unit. Each CuIIatom has a distorted ocahedral coordination environment defined by two N atoms and four O atoms from two tridentate 1-[(E)-(2-methoxyphenyl)diazenyl]naphthalen-2-olate ligands. In the crystal, the two molecules are linkedviaweak C—H...O hydrogen bonds which in turn stack parallel to [010]. A region of disordered electron density, most probably disordered methanol solvent molecules, was corrected for using the SQUEEZE routine inPLATON[Spek (2015).Acta Cryst.C71, 9–18]. Their formula mass and unit-cell characteristics were not taken into account during refinement.


1980 ◽  
Vol 33 (2) ◽  
pp. 295
Author(s):  
SR Hall ◽  
CL Raston ◽  
AH White

The crystal structure of the title compound, C60H86O4, has been determined at 295 K by single-crystal X-ray diffraction and refined by least squares to a residual of 0.073 for 3399 'observed' reflections. Crystals are monoclinic, P21/n, a 18.999(10), b 12.149(7), c 27.589(10) Ǻ, β 107.32(6)°, Z 4. The compound is solvated with ether to the extent of about two solvent molecules per unit cell.


2017 ◽  
Vol 73 (2) ◽  
pp. 148-157 ◽  
Author(s):  
Dorothee Liebschner ◽  
Pavel V. Afonine ◽  
Nigel W. Moriarty ◽  
Billy K. Poon ◽  
Oleg V. Sobolev ◽  
...  

The crystallographic maps that are routinely used during the structure-solution workflow are almost always model-biased because model information is used for their calculation. As these maps are also used to validate the atomic models that result from model building and refinement, this constitutes an immediate problem: anything added to the model will manifest itself in the map and thus hinder the validation. OMIT maps are a common tool to verify the presence of atoms in the model. The simplest way to compute an OMIT map is to exclude the atoms in question from the structure, update the corresponding structure factors and compute a residual map. It is then expected that if these atoms are present in the crystal structure, the electron density for the omitted atoms will be seen as positive features in this map. This, however, is complicated by the flat bulk-solvent model which is almost universally used in modern crystallographic refinement programs. This model postulates constant electron density at any voxel of the unit-cell volume that is not occupied by the atomic model. Consequently, if the density arising from the omitted atoms is weak then the bulk-solvent model may obscure it further. A possible solution to this problem is to prevent bulk solvent from entering the selected OMIT regions, which may improve the interpretative power of residual maps. This approach is called a polder (OMIT) map. Polder OMIT maps can be particularly useful for displaying weak densities of ligands, solvent molecules, side chains, alternative conformations and residues both in terminal regions and in loops. The tools described in this manuscript have been implemented and are available inPHENIX.


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