Gideon Steyl
University of the Free State
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Acta Crystallographica Section E-structure Reports Online | 2008
Maryke Steyn; Andreas Roodt; Gideon Steyl
In the title compound, [Zr(C5H4F3O2)4]·C7H8, the Zr atom is in a square-antiprismatic coordination geometry that comprises four O,O′-bidentate trifluoroacetylacetonate ligands. The O—Zr—O bite angles of the acetonate ligands range from 75.27 (5) to 75.41 (5)°. The Zr atom is located on a twofold rotation axis.
Acta Crystallographica Section E-structure Reports Online | 2009
Gertruida J. S. Venter; Gideon Steyl; Andreas Roodt
In the title compound, [Rh(C13H16NO)(C18H15P)(CO)]·0.5C3H6O, the Rh atom exhibits a square-planar coordination geometry, being coordinated by the N and O atoms of the bidentate β-diketonato ligand, a P atom from the triphenylphosphine unit and a C atom from the carbonyl group. The asymmetric unit also contains a disordered half-molecule, lying about an inversion center, of the acetone solvate. Intermolecular C—H⋯O hydrogen bonds are observed between a C—H group of the triphenylphosphine unit and a carbonyl O atom and between the methyl group of the enaminoketonato backbone and the solvent O atom. In addition, an intramolecular interaction is observed between a C—H group of the triphenylphosphine unit and the O atom of the enaminoketonato ligand.
Acta Crystallographica Section E-structure Reports Online | 2010
Gertruida J. S. Venter; Gideon Steyl; Andreas Roodt
The title enaminoketone, C12H15NO, is a derivative of 4-(phenylamino)pent-3-en-2-one with an approximately planar pentenone backbone, the greatest displacement from the plane being 0.042 (1) Å; the asymmetry in C—C distances in the group suggests the presence of unsaturated bonds. The dihedral angle between the benzene ring and the pentenone plane is 29.90 (4)°. In the crystal, an intramolecular N—H⋯O interaction and an intermolecular C—H⋯O hydrogen bond are observed.
Acta Crystallographica Section E-structure Reports Online | 2009
Gertruida J. S. Venter; Gideon Steyl; Andreas Roodt
In the title compound, [Rh(C13H16NO)(C18H15P)(CO)], the coordination geometry of the RhI atom is square-planar, formed by the coordinating N and O atoms of the bidentate enaminoketonate ligand, one C atom from the carbonyl group and a P atom from triphenylphosphine. The complex displays a 0.591 (3):0.409 (3) ratio disorder of the phenyl unit of the monoanionic N,O-bidentate ligand. Intramolecular hydrogen bonding is observed between a C—H group of the triphenylphosphine unit and the O atom of the enaminoketonate ligand.
Journal of Coordination Chemistry | 2014
Gertruida J. S. Venter; Gideon Steyl; Andreas Roodt
A series of five rhodium(I) dicarbonyl complexes containing systematically introduced phenyl-chloro substituted mono-anionic β-enaminoketonato ligands (N,O-bidentate donors) are presented. The influence of chloro substitution on the phenyl ring was investigated in the solid state and by theoretically optimized structures. Chloro substitution on the phenylamino ring in dicarbonyl [2-(phenylamino)pent-3-en-4-onato]rhodium(I) complexes were thus investigated with regard to optimized energies, metal–metal interactions, and bonding distances and angles primarily using X-ray diffraction and DFT calculations. The five complexes crystallized in three different crystal systems and five separate space groups. The packing modes of the complexes were evaluated by considering the relative orientation and metal–metal interactions and were found to be influenced by different factors, including weak intermolecular hydrogen bonds. Although no significant Cl⋯Cl interactions were observed, significant Rh⋯Rh bonding was identified. The theoretically optimized structures correlate very well with the solid state, with RMS overlay values varying between 0.62 and 0.23 Å. Upon coordination, the phenyl ring of the enaminato ligand adopts, without exception, an approximately 90° dihedral angle relative to the coordination plane, inducing a significant corresponding steric hindrance at the metal center. This is manifested by the complete blocking out of the well-known iodomethane oxidative addition reaction. Graphical Abstract
Acta Crystallographica Section E-structure Reports Online | 2012
Gertruida J. S. Venter; Gideon Steyl; Andreas Roodt
In the title compound, [Rh(C13H16NO)(CO)2], a square-planar coordination geometry is observed around the RhI atom, formed by the N and O atoms of the bidentate ligand and two C atoms from two carbonyl ligands. The RhI atom is displaced from the plane through these surrounding atoms by 0.0085 (2) Å. The dihedral angle between the benzene ring and the N—C—C—C—O plane is 89.82 (6)°, and the N—Rh—O bite angle for the bidentate ligand is 90.53 (6)°. An intermolecular C—H⋯O interaction is observed between a methyl group of the benzene ring and a carbonyl O atom.
Acta Crystallographica Section E-structure Reports Online | 2010
Gertruida J. S. Venter; Gideon Steyl; Andreas Roodt
The title enamino ketone, C12H15NO, a derivative of 4-(phenylamino)pent-3-en-2-one, presents a roughly planar [greatest displacement of an atom from the pentenone plane is 0.033 (2) Å] pentenone backbone, enhanced by an intramolecular N—H⋯O hydrogen bond; the asymmetry in C—C distances in the group suggests the presence of unsaturated bonds. The overall geometry in the free ligand differs significantly from that in other reported compounds, in which it is coordinated to rhodium; this is reflected in the bond distances [the N⋯O distance is significantly increased (0.2 Å) upon coordination to the metal] and the dihedral angle between the benzene ring and the pentenone backbone [49.53 (5)°]. All of the methyl goups are rotationally disordered over two orientations of equal occupancy.
Acta Crystallographica Section E-structure Reports Online | 2010
Gideon Steyl; Theunis J. Muller; Andreas Roodt
In the title compound, [Cu(C8H8NO)2], a strictly square-planar geometry about the CuII metal atom is observed. Substitution of an O atom with a methyl-functionalized N atom does not significantly alter the bond distances and angles in the copper(II) complex when compared with a similar bis(troponato)copper(II) complex. π–π stacking is observed between the tropolone rings, with interplanar distances of 3.5039 (16) and 3.2933 (15) Å, respectively. Additional stabilisation of the structure is accomplished through C—H⋯O hydrogen-bonding interactions.
Acta Crystallographica Section E: Crystallographic Communications | 2006
Gideon Steyl
A new type of α-diketone palladium(II) complex containing a tertiary phosphine, namely the title compound, [Pd(C7H5O2)2(C18H33P)], crystallizes with a square-planar geometry about the palladium(II) metal centre. One tropolonate ligand is bonded in a bidentate chelating mode, while the second one is bonded through a single O atom to the palladium(II) metal centre. The Pd—O distances range from 1.9907 (13) to 2.0702 (12) A, and the O—Pd—O bite angle for the bidentate tropolonate ligand is 80.30 (5)°.
Acta Crystallographica Section E-structure Reports Online | 2013
Gertruida J. S. Venter; Gideon Steyl; Andreas Roodt
The asymmetric unit of the title compound, C6H5Cl2N·2C11H11Cl2NO, is composed of one molecule of an enamino–ketone [i.e. –(2,6-dichlorophenylamino)pent-3-en-2-one] and half a molecule of 2,6-dichloroaniline, the whole molecule of the latter component being generated by twofold rotational symmetry. In this latter molecule, there are two intramolecular N—H⋯Cl contacts. In the enamino–ketone molecule, there is an N—H⋯O hydrogen bond of moderate strength, and the dihedral angle between the benzene ring and pentanone fragment [C—C(—N)=C—C(=O)—C; planar within 0.005 (1) Å] is 81.85 (7)°. In the crystal, two molecules of the enamino–ketone are bridged by a molecule of 2,6-dichloroaniline via N—H⋯O hydrogen bonds of moderate strength. There are also π–π interactions present, involving the benzene rings of inversion-related enamino–ketone molecules [centroid–centroid distance = 3.724 (4) Å].