Theunis J. Muller

Tetra-kis(picolinato-κN,O)zirconium(IV) dihydrate.

In the title compound, [Zr(C6H4NO2)4]·2H2O, the ZrIV atom is located on a crystallographic fourfold rotoinversion axis () and is coordinated by four picolinate anions with Zr—O and Zr—N distances of 2.120 (2) and 2.393 (2) Å, respectively. An approximate square-antiprismatic coordination polyhedron of the N,O-coordination ligand atoms is formed, with a distortion towards dodecahedral geometry. The crystal packing is stabilized by intermolecular π–π interactions between adjacent picolinate rings [centroid–centroid distances = 3.271 (1) and 3.640 (2) Å], as well as O—H⋯O hydrogen bonds between the solvent molecules and the coordinated ligands, thereby linking the molecules into a supramolecular three-dimensional network.

Bis[2-(methyl-amino)-troponato]copper(II).

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.

2',3,4,4'-Tetra-meth-oxy-chalcone.

In the title compound [systematic name: 1-(2,4-dimethoxyphenyl)-3-(3,4-dimethoxyphenyl)prop-2-en-1-one], C19H20O5, the dihedral angle between the benzene rings is 26.88 (5)°. One of the methoxy groups is twisted slightly away from the plane [C—O—C—C torsion angle = −12.8 (3)°] while the others are almost co-planer [C—O—C—C torsion angles = −3.2 (3), 2.6 (3) and −3.6 (3)°]. The crystal packing is stabilized by intermolecular C—H⋯O interactions. A weak intramolecular C—H⋯O interaction occurs.

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.

Distorted octahedral environments in tricarbonylrhenium(I) complexes of 5-[2-(2,4,6-trimethylphenyl)diazen-1-yl]quinolin-8-olate and 5,7-bis[2-(2-methylphenyl)diazen-1-yl]quinolin-8-olate.

The Re(I) centres of two Re(I)-tricarbonyl complexes, viz. tricarbonyl(pyridine-κN){5-[2-(2,4,6-trimethylphenyl)diazen-1-yl]quinolin-8-olato-κ(2)N(1),O}rhenium(I), [Re(C23H21N4O)(CO)3], (I), and {5,7-bis[2-(2-methylphenyl)diazen-1-yl]quinolin-8-olato-κ(2)N(1),O}tricarbonyl(pyridine-κN)rhenium(I), [Re(C28H23N6O)(CO)3], (II), are facially surrounded by three carbonyl ligands, a pyridine ligand and either a 5-[2-(2,4,6-trimethylphenyl)diazen-1-yl]quinolin-8-olate [in (I)] or a 5,7-bis[2-(2-methylphenyl)diazen-1-yl]quinolin-8-olate [in (II)] ligand, in a slightly distorted octahedral environment. The crystal structure of (I) is stabilized by two intermolecular C-H···O interactions and that of (II) is stabilized by three intermolecular C-H···O hydrogen-bonding interactions.

4,5-Bis(2,4-di-tert-butyl-phen-oxy)phthalonitrile.

In the title compound, C36H44N2O2, the dihedral angles between the phthalonitrile ring and the two di-tert-butylbenzene rings are 68.134 (8) and 70.637 (11)°. The two nitrile groups are almost coplanar with the phthalonitrile ring except for one of the N atoms which deviates from the plane by 0.125 (4) Å. One of the tert-butyl groups is disordered over two orientations, with refined occupancies of 0.814 (6) and 0.186 (6). Intramolecular C—H⋯O interactions stabilize the molecular structure. The crystal packing is stabilized by intermolecular C—H⋯N interactions.

2',3,4,4',5-Penta-meth-oxy-chalcone.

In the title chalcone [systemetic name 1-(2,4-dimethoxyphenyl)-3-(3,4,5-trimethoxyphenyl)prop-2-en-1-one], C20H22O6, the dihedral angle between the plane of the two benzene rings is 7.03 (4)° with all but one of the methoxy groups essentially co-planar with these rings [C—C—O—C torsion angles = −76.1 (2), −0.7 (3), 1.8 (3), −6.2 (3), 2.0 (3)°]. An intramolecular C—H⋯O interaction occurs. The crystal packing is stabilized by weak intermolecular C—H⋯O hydrogen bonds.

[Bis(pyridin-2-ylmeth-yl)amine-κ(3)N,N',N'']tricarbonyl-rhenium(I) bromide hemihydrate.

The title compound, fac-[Re(C12H12N3)(CO)3]Br·0.5H2O, crystallizes with a cationic rhenium(I) unit, a bromide ion and half a water molecule, situated on a twofold rotation axis, in the asymmetric unit. The ReI atom is facially surrounded by three carbonyl ligands and a tridentate bis(pyridin-2-ylmethyl)amine ligand in a distorted octahedral environment. N—H⋯Br, O—H⋯Br, C—H⋯O and C—H⋯Br hydrogen bonds are present in the crystal structure and π–π stacking is also observed [centroid–centroid distances = 3.669 (1) Å and 4.054 (1) Å], giving rise to a three-dimentional network. The molecules pack in a head-to-head fashion along the ac plane.

N,N′-(4,5-Dimethyl-1,2-phenyl­ene)bis­(pyridine-2-carboxamide)

In the title compound, C20H18N4O2, the dihedral angles between the central benzene ring and the pyridine rings are 57.55 (6) and 22.05 (8)°. The molecular conformation is stabilized by intramolecular N—H⋯N interactions and in the crystal structure an intermolecular asymmetric cyclic hydrogen-bonding association involving both amide N—H donors and a common amide O-atom acceptor gives a chain extending along the c axis.

5-(3,4-Dimeth­oxy­benzyl­idene)-1,3-dimethyl-1,3-diazinane-2,4,6-trione

In the title compound, C15H16N2O5, the dihedral angle between 1,3-diazinane and benzene rings is only 4.27 (1)°. The essentially planar molecular structure is characterized by a short intramolecular C—H⋯O separation and by an exceptionally large bond angle of 138.25 (14)° at the bridging methine C atom. The methoxy groups deviate somewhat from the plane of the benzene ring, with C—C—O—C torsion angles of −15.6 (1) and 9.17 (6)°. In the crystal, molecules form centrosymmetric dimers via donor–acceptor π–π interactions, with a centroid–centroid distance of 3.401 (1) Å.