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.

N,N'-(4,5-Dimethyl-1,2-phenyl-ene)bis-(pyridine-2-carboxamide).

In the title compound, C(20)H(18)N(4)O(2), the dihedral angles between the central benzene ring and the pyridine rings are 57.55 (6) and 22.05 (8)°.

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

The title compound, fac-[Re(C(12)H(12)N(3))(CO)(3)]Br·0.5H(2)O, crystallizes with a cationic rhenium(I) unit, a bromide ion and half a water mol-ecule, situated on a twofold rotation axis, in the asymmetric unit. The Re(I) atom is facially surrounded by three carbonyl ligands and a tridentate bis-(pyridin-2-ylmeth-yl)amine ligand in a distorted octahedral environment.

5-(3,4-Dimeth-oxy-benzyl-idene)-1,3-dimethyl-1,3-diazinane-2,4,6-trione.

In the title compound, C(15)H(16)N(2)O(5), the dihedral angle between 1,3-diazinane and benzene rings is only 4.27 (1)°. The essentially planar mol-ecular structure is characterized by a short intra-molecular C-H⋯O separation and by an exceptionally large bond angle of 138.

Dimethyl 2,6-dimethyl-4-phenyl-pyridine-3,5-dicarboxyl-ate.

In the title compound, C(17)H(17)NO(4), the dihedral angle between the benzene and pyridine rings is 75.51 (4)°. The benzene and pyridine rings are both approximately planar (r.

1,1,1,5,5,5-Hexafluoro-2,4-dimeth-oxy-pentane-2,4-diol.

The title compound, C(7)H(10)F(6)O(4), was isolated as an unexpected product from a reaction of tantalum(V) methoxide with hexa-fluoro-acetyl-acetone in a methanol solution. The asymmetric unit consists of one half-mol-ecule with the middle C atom lying on a twofold axis. The crystal structure is stabilized by O-H⋯O and an array of C-H⋯F hydrogen-bonding inter-actions.

Acetonitrile-trichloridobis(cyclo-hexyl-diphenyl-phosphane)rhodium(III) acetonitrile disolvate.

In the title compound, [RhCl(3)(CH(3)CN)(C(18)H(21)P)(2)]·2CH(3)CN, the complex mol-ecule lies on a twofold rotation axis that passes through the Rh(III) atom, one Cl atom, and the C and N atoms of the coordinated acetonitrile mol-ecule. The Rh(III) atom is coordinated by two P atoms in trans positions, three Cl atoms and an acetonitrile mol-ecule in a distorted octa-hedral geometry. Intra-molecular C-H⋯Cl inter-actions are observed.

cyclo-Tetra-μ-oxido-tetra-kis-[(acetyl-acetonato-κO,O')bis-(ethano-lato-κO)niobium(V)].

The asymmetric unit of the title tetra-nuclear niobium(V) compound, [Nb(4)(C(2)H(5)O)(8)(C(5)H(7)O(2))(4)O(4)], contains two Nb(V) atoms, two bridging O atoms, two acetyl-acetonate and four ethano-late ligands. Each Nb(V) atom is six-coordinated by the bridging O atoms, two ethano-late and one chelating acetyl-acetonate ligands. The Nb-O distances vary between 1.

(2-Methyl-4-oxo-4H-pyran-3-olato-κO,O)bis-(triphenyl-phosphane-κP)copper(I)-triphenyl-phosphane-methanol (1/1/1).

In the title compound, [Cu(C(6)H(5)O(3))(C(18)H(15)P)(2)]·C(18)H(15)P·CH(3)OH, the pyran-4-one ring is appromimately planar (r.m.s deviation = 0.

Racemic tricarbon-yl[7-meth-oxy-2-(η-phen-yl)chromane]-chromium(0).

In the title compound, [Cr(C(16)H(16)O(2))(CO)(3)], the Cr(0) atom of the Cr(CO)(3) unit is coordinated to the phenyl ring of the flavan ligand in an η(6) mode, with a normal arene-to-metal distance. The Cr(CO)(3) unit exhibits a three-legged piano-stool conformation, while the dihydro-pyran ring displays a distorted envelope configuration. The phenyl ring is twisted away from the fused ring system by 25.

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

In the title compound, C(36)H(44)N(2)O(2), the dihedral angles between the phthalonitrile ring and the two di-tert-butyl-benzene rings are 68.134 (8) and 70.637 (11)°.

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

In the title compound, [Cu(C(8)H(8)NO)(2)], a strictly square-planar geometry about the Cu(II) 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 inter-planar distances of 3.

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

In the title chalcone [systemetic name 1-(2,4-dimeth-oxy-phen-yl)-3-(3,4,5-trimeth-oxy-phen-yl)prop-2-en-1-one], C(20)H(22)O(6), the dihedral angle between the plane of the two benzene rings is 7.03 (4)° with all but one of the meth-oxy groups essentially co-planar with these rings [C-C-O-C torsion angles = -76.1 (2), -0.

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], C(19)H(20)O(5), the dihedral angle between the benzene rings is 26.88 (5)°. One of the meth-oxy groups is twisted slightly away from the plane [C-O-C-C torsion angle = -12.