Bis[(1RS,2RS)-4,4'-(1-aza-niumyl-2-hy-droxy-ethane-1,2-di-yl)dipyridinium] tris-[tetra-chloridopalladate(II)].

The asymmetric unit of the title compound, (C12H16N3O)2[PdCl4]3, consists of a 4,4'-(1-aza-niumyl-2-hy-droxy-ethane-1,2-di-yl)dipyridinium dication and one and a half tetra-chloridopalladate(II) anions; the latter has inversion symmetry. In the cation, the pyridinium rings attached to the central 1-aza-niumyl-2-hy-droxy-ethane fragment show an anti conformation, as indicated by the central C-C-C-C torsion angle of -178.1 (4)°, and they are inclined to one another by 25.7 (2)°. In the crystal, the cations and anions are linked through N-H⋯Cl and O-H⋯Cl hydrogen bonds. There are also π-π contacts [centroid-centroid distance = 3.788 (3) Å] and a number of C-H⋯O and C-H⋯Cl inter-actions are present, consolidating the formation of a three-dimensional structure.

(1RS,2RS)-4,4'-(1-Aza-niumyl-2-hy-droxy-ethane-1,2-di-yl)dipyridinium tetra-chlorido-platinate(II) chloride.

The title compound, (C12H16N3O)[PtCl4]Cl, consists of a 4,4'-(1-aza-niumyl-2-hy-droxy-ethane-1,2-di-yl)dipyridinium trication, a square-planar tetra-chloridoplatinate(II) dianion and a chloride ion. In the cation, the pyridinium rings attached to the central 1-aza-niumyl-2-hy-droxy-ethane fragment have an anti conformation, as indicated by the central C-C-C-C torsion angle of -166.5 (6)°, and they are inclined to one another by 63.5 (4)°. In the crystal, the cations and anions are linked through N-H⋯Cl and O-H⋯Cl hydrogen bonds. There are also π-π contacts [centroid-centroid distances = 3.671 (4) and 3.851 (4) Å] and a number of C-H⋯Cl inter-actions present, consolidating the formation of a three-dimensional supra-molecular structure.

N-{1,2-Bis(pyridin-3-yl)-2-[(E)-(pyridin-3-yl)methyl-idene-amino]-eth-yl}nicotinamide.

In the title compound, C24H20N6O, the pyridin-3-yl groups on the ethyl-ene fragment are found in a trans conformation with a C(py)-C(e)-C(e)-C(py) (py = pyridine, e = ethylene) torsion angle of 179.2 (3)°. The dihedral angle between the pyridine rings is 3.5 (1)°. In the crystal, N-H⋯N and C-H⋯O=C inter-actions form a layer arrangement parallel to the bc plane. The compound displays disorder of the ethyl-ene fragment over two positions with an occupancy ratio of 0.676 (7) to 0.324 (7) that extends into the amide section of the nicotinamide moiety.

1,3,5-Tris(pyridin-3-yl)-2,4-diaza-penta-1,4-diene.

In the solid state, the structure of the title compound, C(18)H(15)N(5), is stabilized by weak C-H⋯N interactions. Mol-ecules are arranged in layers parallel to the bc plane forming an inter-esting supra-molecular structure.

2,4,5-Tris(pyridin-4-yl)-4,5-dihydro-1,3-oxazole.

In the title compound, C(18)H(14)N(4)O, the mol-ecules are disordered about a crystallographic twofold axis, leading to 50:50 disorder of the O- and N-atom sites within the oxazole ring. As a consequence, symmetry-related oxazole C-N and C-O bonds are averaged. The oxazole ring makes a dihedral angle of 6.920 (1)° with the pyridyl ring in the 2-position and 60.960 (2)° with the pyridyl rings in the 4- and 5-positions.

Tetra-kis(µ-acetato-κ(2)O:O')-bis-[(3-pyridine-carboxaldehyde-κN')]dicopper(II)(Cu-Cu).

The binuclear title compound, [Cu(2)(CH(3)CO(2))(4)(C(6)H(5)NO)], is located about a center of inversion. The Cu(II) atoms are connected [Cu-Cu = 2.6134 (5) Å] and bridged by four acetate ligands. Their distorted octa-hedral coordination geometry is completed by a terminal pyridine N atom of a 3-pyridincarboxaldehyde ligand. In the crystal, the complex mol-ecules are linked by C-H⋯O hydrogen bonds, forming two-dimensional networks lying parallel to the ab plane. These networks are linked via C-H⋯O hydrogen bonds involving inversion-related 3-pyridinecarboxaldehyde ligands, forming a three dimensional supra-molecular architecture.

3-[(R)-1-Hy-droxy-butan-2-yl]-1,2,3-benzo-triazin-4(3H)-one.

The crystal structure of the title compound, C(11)H(13)N(3)O(2), is stabilized by O-H⋯O hydrogen bonds, which link the mol-ecules into chains along [100].

Two coordination modes of Cu(II) in a binuclear complex with N-(pyridin-2-yl-carbon-yl)pyridine-2-carboxamidate ligands.

In the title dinuclear complex, (acetonitrile-1κN)[µ-N-(pyri-din-2-ylcarbonyl)pyridine-2-carboxamidato-1:2κ(5)N,N',N'':O,O'][N-(pyridin-2-ylcarbonyl)pyridine-2-carboxamidato-2κ(3)N,N',N'']bis(trifluoromethanesulfonato-1κO)dicopper(II), [Cu(2)(C(12)H(8)N(3)O(2))(2)(CF(3)O(3)S)(2)(CH(3)CN)], one of the Cu(II) ions is five-coordinated in a distorted square-pyramidal N(3)O(2) environment provided by two N-(pyridin-2-ylcarbon-yl)pyridine-2-carboxamidate (bpca) ligands, while the second Cu(II) ion is six-coordinated in a distorted octa-hedral N(4)O(2) environment provided by one bpca ligand, two trifluoro-methansulfonate ligands and one acetonitrile mol-ecule. Weak inter-molecular C-H⋯O and C-H⋯F hydrogen bonds and π-π stacking inter-actions with centroid-centroid distances of 3.6799 (15) and 3.8520 (16) Šstabilize the crystal packing and lead to a three-dimensional network.

Dichloridobis(methanol-κO)[cis-(±)-2,4,5-tris-(pyridin-2-yl)-2-imidazoline-κ(3)N(2),N(3),N(4)]ytterbium(III) chloride.

In the crystal structure of the title complex, [YbCl(2)(C(18)H(15)N(5))(CH(3)OH)(2)]Cl, the pseudo-penta-gonal-bipyramidal coordination geometry of the Yb(III) cation is composed of three N atoms from one cis-(±)-2,4,5-tris-(pyridin-2-yl)imidazoline (HL) ligand, two O atoms from two methanol mol-ecules and two Cl(-) anions. Chains are formed along [010] through N-H⋯Cl, O-H⋯Cl and O-H⋯N hydrogen bonds.

Asymmetric transfer hydrogenation of prochiral ketones in aqueous media with chiral water-soluble and heterogenized bifunctional catalysts of the RhCp*-type ligand.

Asymmetric transfer hydrogenation (ATH) of prochiral aromatic ketones was carried out with a water-soluble complex of Rh(III)Cp* and mononitrobenzenesulfonamide bidentate ligand (1R,2R)-N-(2-aminocyclohexyl)-4-nitrobenzenesulfonamide 1 derived from chiral cyclohexane-1,2-diamine. Aqueous sodium formate was used as the hydride source. The reaction afforded the chiral alcohols in good enantioselectivities (79-93%) and yields (>99%). The modified monosulfonamide ligand was also covalently immobilized on solid phase such as silica, resin, and mesoporous SBA-15 silica and then explored as a catalyst with Rh(III)Cp* in the ATH of acetophenone.

N-(2-Hydroxy-ethyl)-2-[3-(p-tol-yl)triazen-1-yl]benzamide.

In the solid state, the structure of the title compound, C(16)H(18)N(4)O(2), is stabilized by inter-molecular N-H⋯O and O-H⋯O hydrogen bonds. These hydrogen bonds arrange the mol-ecules into a double-layer supra-molecular structure. The mol-ecular conformation is is consolidated by an intra-molecular N-H⋯N hydrogen bond. The dihedral angle between the aromatic rings is 8.01 (10)°

Binuclear palladium(I) and palladium(II) complexes of ortho-functionalized 1,3-bis(aryl)triazenido ligands.

Three new bis(aryl)triazene ligands, Ar-NNNH-Ar' [Ar = o-C(6)H(4)-CO(2)Me, Ar' = p-C(6)H(4)-CH(3) (2); Ar = Ar' = o-C(6)H(4)-CO(2)Me (3); Ar = o-C(6)H(4)-SMe, Ar' = p-C(6)H(4)-CH(3)) (4)], have been synthesized. The reaction of 1-4 with PdCl(2)(NCCH(3))(2) in the presence of a base afforded a series of binuclear diamagnetic palladium complexes. In these reactions, ligands 1-3 afforded the palladium(I) complexes [Pd(I)(o-MeO(2)C-C(6)H(4)-NNN-o-C(6)H(4)-CO(2)Me)](2) (5, monoclinic, space group P21/c, a = 8.6070(10) Angstrom, b = 14.3220(10) Angstrom, c = 12.7310(10) Angstrom, beta = 100.2950(10) degrees, Z = 2), [Pd(I)(o-MeO-C(6)H(4)-NNN-o-C(6)H(4)-OMe)](2) (6, triclinic, space group P, a = 6.6288(5) Angstrom, b = 10.2631(10) Angstrom, c = 11.0246(11) Angstrom, alpha = 85.579(6) degrees, beta = 80.885(6) degrees, gamma = 74.607(6) degrees, Z = 1), and [Pd(I)(o-MeO(2)C-C(6)H(4)-NNN-p-C(6)H(4)-CH(3))](2) (7, tetragonal, space group I41/a, a = 20.866(3) Angstrom, b = 20.866(3) Angstrom, c = 13.156(2) Angstrom, Z = 8). In contrast, the reaction of ligand 4 with PdCl(2)(NCCH(3))(2) resulted in the formation of a palladium(II) dimer, [Pd(II)(o-MeS-C(6)H(4)-NNN-p-C(6)H(4)-CH(3))Cl](2) (8, orthorhombic, space group P2(1)2(1)2, a = 10.4058(5) Angstrom, b = 16.2488(8) Angstrom, c = 9.9500(5) Angstrom, Z = 2).

Crescent-shaped rhodium(I) complexes with bis(o-carboxymethylphenyl)triazenide.

Reaction of [[Rh(mu-Cl)(CO)2]2] with the triazene ArNNNHAr (Ar = o-CO2MeC6H4) produced the mononuclear complex [RhCl(ArNNNHAr)(CO)2] (1). Complex 1 reacted with KOH in methanol to give the dinuclear compound [[Rh(mu-ArNNNAr)(CO)2]2] (2), which showed a "mu-(1kappaN1,2kappaN3)-ArNNNAr" coordination mode for both bridging ligands. The dinuclear complex [[Rh(mu-ArNNNAr)(CO)2]2] (2) easily undergoes redistribution reactions in which the eight-membered "Rh2(NNN)2" core is broken. Thus, reaction of 2 with the anionic complex (NHEt3)[RhCl2(CO)2] gave the single-bridged complex (NHEt3)[Rh2(mu-ArNNNAr)Cl2(CO)4] (4), while the trinuclear complexes [Rh3(mu-ArNNNAr)(mu-Cl)(mu-CO)Cl(CO)4] (5) and [Rh3(mu-ArNNNAr)2(mu-Cl)(mu-CO)(CO)3] (6) were isolated by addition of the neutral compound [[Rh(mu-Cl)(CO)2]2] to 2, depending on the molar ratio employed. The formation of 5 and 6 involved the loss of carbonyl groups and the coordination of the oxygen atoms of the CO2Me groups. The structures of 4, 5, and 6 have been determined by X-ray diffraction methods, which show the ability of bis(o-carboxymethylphenyl)triazenide to act as bi-, tri-, and tetra-dentate ligand-spanning dinuclear moieties in trinuclear complexes.