Johan A. Venter

Di-μ-iodido-bis­[acet­yl(4-methyl-2,6,7-trioxa-1-phosphabicyclo­[2.2.2]octa­ne)(N-nitroso-N-oxidoaniline-κ2O,O′)rhodium(III)]

The title compound, [Rh2(C6H5N2O2)2(C2H3O)2I2(C5H9O3P)2], contains a binuclear centrosymmetric RhIII dimer bridged by iodide anions, with respective Rh⋯Rh and I⋯I distances of 4.1437 (5) and 3.9144 (5) Å. The RhIII atom is in a distorted octahedral RhCI2O2P coordination with considerably different Rh—I distances to the bridging iodide anions. There are no classical hydrogen-bonding interactions observed for this complex.

Dipotassium diaqua­bis(methyl­enedi­phospho­nato-κ2O,O′)cobaltate(II)

In the title complex, K2[Co(CH4O6P2)2(H2O)2], the asymmetric unit contains two K+ cations and two half-anions in which the Co atoms lie on inversion centers. The CoII ions assume an octahedral CoO6 coordination geometry. In the crystal, a three-dimensional network is formed through O—H⋯O hydrogen-bond interactions as well as intermolecular interactions between the K+ cations and neighbouring O atoms.

Pyridinium diaqua­bis­(methyl­enediphospho­nato-κ2O,O′)chromate(III) tetra­hydrate

In the title complex, (C5H6N)[Cr(CH4O6P2)2(H2O)2]·4H2O, the CrIII atom, lying on an inversion centre, is coordinated by two bidentate methylene diphosphonate ligands and two water molecules in a distorted octahedral coordination geometry. The pyridinium cation is located on an inversion centre, with an N atom and a C atom sharing a position each at a half occupancy. A three-dimensional network is constructed by O—H⋯O, N—H⋯O and C—H⋯O hydrogen bonds between the pyridinium cation, complex anion and uncoordinated water molecules.

(N-Benzoyl-N′-phenyl­thio­urea-κS)chlorido(η4-1,5-cyclo­octa­diene)rhodium(I)

The title compound, [RhCl(C8H12)(C14H12N2OS)], is a rhodium(I) derivative with a functionalized thiourea ligand. Despite the presence of several heteroatoms, the thiourea ligand coordinates only in a monodentate fashion via the S atom. The geometry of the coordination sphere is approximately square planar about the RhI atom, with two bonds to the π-electrons of the 1,5-cyclooctadiene ligand, one bond to the Cl− ligand and one bond to the S atom of the thiourea ligand. The molecular structure is stabilized by intramolecular N—H⋯O and N—H⋯Cl hydrogen bonding. Intermolecular N—H⋯O hydrogen-bonding interactions lead to the formation of layers extending parallel to (011).

Carbon­yl(N-nitroso-N-oxido-1-naphtylamine-κ2O,O′)(triphenyl­phosphine-κP)rhodium(I) acetone solvate

The title compound, [Rh(C10H7N2O2)(C18H15P)(CO)]·(CH3)2CO, is the second structural report of a metal complex formed with the O,O′-C10H7N2O2 (neocupferrate) ligand. In the crystal structure, the metal centre is surrounded by one carbonyl ligand, one triphenylphosphine ligand and the bidentate neocupferrate ligand, forming a distorted square-planar RhCO2P coordination set which is best illustrated by the small O—Rh—O bite angle of 77.74 (10)°. There are no classical hydrogen-bond interactions observed for this complex.

Diammonium diaqua­bis(methyl­enediphospho­nato-κ2O,O′)cobaltate(II)

In the salt, (NH4)2[Co(CH4O6P2)2(H2O)2], the methylenediphosphonate acts as a bidentate ligand and the CoII ion (site symmetry ) assumes an octahedral CoO6 coordination geometry. The acid H atom of the ligand is distributed over two O atoms. In the crystal, a three-dimensional network is formed through O—H⋯O and N—H⋯O hydrogen bonds between the cations and anions.

Characterization and oxidative addition reactions for iridium cod complexes

Abstract Three different [Ir(LL′)(cod)] complexes (LL′ = N-aryl-N-nitrosohydroxylaminato) (cupf), trifluoroacetylacetonato (tfaa), and (methyl 2-(methylamino)-1-cyclopentene-1-dithiocarboxylato-κN,κS) (macsm)) were synthesized, characterized, and their rates of oxidative addition with methyl iodide were determined. Formation of an isosbestic point during the oxidative addition of methyl iodide with the complexes containing tfaa and cupf as bidentate ligands indicated formation of only one product, while an increase in absorbance maximum observed for macsm confirms that the same reaction between the complex and methyl iodide occurs. Kinetic results for all complexes, except [Ir(tfaa)(cod)], showed simple second-order kinetics with a zero intercept (within experimental error). Rates of oxidative addition for bidentate ligands in acetonitrile showed an increase of an order of magnitude with a change in the type of bidentate ligands. Computational chemistry using density functional theory calculations showed that the oxidative addition reaction proceeds through a “linear” transition state with the methyl iodide unit tilted towards the LL′-bidentate ligand.

Crystal structure of carbonyl(2-oxopyridin-1(2H)-olato-κ2O, O′)(triphenylphosphine-κP)rhodium(I), C24H19NO3PRh

Abstract C24H19NO3PRh, triclinic, P1̅ (no. 2), a = 9.1734(16) Å, b = 9.5433(18) Å, c = 12.342(2) Å, α = 92.400(6)°, β = 105.460(5)°, γ = 99.472(5)°, V = 1023 Å3, Z = 2, Rgt(F) = 0.0236, wRref(F2) = 0.0597, T = 100 K.

trans-Bis(1,3-diphenyl­propane-1,3-dionato)(methanol)oxidovanadium(IV) methanol disolvate

In the title compound, [V(C15H11O2)2O(CH3OH)]·2CH3OH, the VIV atom is coordinated by two 1,3-diphenylpropane-1,3-dionate ligands and an oxide ligand in an axial position. The sixth position is occupied by the O atom of a methanol group bonded trans to the oxide atom. The octahedral geometry is significantly distorted, with the VIV atom lying 0.330 (3) Å above the equatorial plane formed by the O atoms of the two β-diketonate ligands. In the crystal, O—H⋯O hydrogen bonds between the coordinating methanol group in the complex and the two methanol solvent molecules lead to the formation of polymeric chains along the c-axis direction. Weak C—H⋯O contacts are also observed.

(Acetylacetonato‐κ2O,O′)carbonyl[2‐(diphenylphosphino)pyridine‐κP]rhodium(I)

The title complex, [Rh(C5H7O2)(C17H14NP)(CO)], adopts a square-planar geometry, with bite angles around the rhodium(I) centre varying between 85.28 (7) and 93.59 (8)°. The two phenyl rings and the one pyridine ring of the phosphine ligand are arranged in a face on/edge on orientation, with dihedral angles between the planes formed by these rings ranging between 66.55 (7) and 80.50 (7)°.