Gertruida J. S. Venter

Isomorphism in monomeric 1:3 complexes of silver(I) salts with tri-p-tolylphosphine.

Reaction of silver(I) salts with three equivalents of tri-p-tolylphosphine in CH(3)CN resulted in a series of isomorphous complexes [AgX{P(4-MeC(6)H(4))(3)}(3)] (X = Br, SCN, ClO(4)). These complexes all crystallize in the orthorhombic space group Pna2(1). The complexes with X = Br, SCN are distorted tetrahedral around the silver(I) atom, whereas the ClO(4)(-) complex is distorted trigonal planar around the silver. The new complexes are compared with each other using r.m.s. overlay calculations as well as half-normal probability plot analysis and with the previously reported isomorphous chloride, bromide as well as the non-isomorphous iodide complexes.

Carbonyl[4-(2,6-dimethyl­phenyl­amino)pent-3-en-2-onato-κ2N,O](triphenyl­phosphine-κP)rhodium(I) acetone hemi­solvate

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.

4-[(4-Methyl­phen­yl)amino]­pent-3-en-2-one

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.

Carbon­yl[4-(2,3-dimethyl­phenyl­amino)pent-3-en-2-onato-κ2 N,O](triphenyl­phosphine-κP)rhodium(I)

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.

Polymorphism in iodotris(tri-p-tolylphosphine)silver(I)

The reaction of silver(I) iodide with tri(p-tolyl)phosphine in MeCN solution in 1:3 molar ratio yields a polymorph of the complex of the formula [AgI{P(4-MeC6H4)3}3], with the Ag atom in a distorted tetrahedral environment. A polymorphic structure of this complex (a) is compared with previously published crystal structures (b), determined at different temperatures. The two polymorphs are compared using r.m.s. overlay calculations as well as half-normal probability plots.

Solid state and theoretical study of structural properties induced by step-wise chloro functionalization in dicarbonyl-[2-(phenylamino)pent-3-en-4-onato]rhodium(I) complexes

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

Dicarbon-yl[4-(2,6-dimethyl-phenyl-amino)-pent-3-en-2-onato-κ(2)N,O]rhodium(I).

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.

4-(2-Methyl­anilino)pent-3-en-2-one

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.

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.

2,6-Dichloro­aniline–4-(2,6-dichloro­anilino)­pent-3-en-2-one (1/2)

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].