Nam-Ho Kim

Redetermination of (2,2′-bipyridine-κ2N,N′)dichlorido­palladium(II) dichloro­methane solvate

In the title compound, [PdCl2(C10H8N2)]·CH2Cl2, the Pd2+ ion is four-coordinated in a slightly distorted square-planar environment by two N atoms of the 2,2′-bipyridine (bipy) ligand and two chloride ions. The compound displays intramolecular C—H⋯Cl hydrogen bonds and pairs of complex molecules are connected by intermolecular C—H⋯Cl hydrogen bonds. Intermolecular π–π interactions are present between the pyridine rings of the ligand, the shortest centroid–centroid distance being 4.096 (3) Å. As a result of the electronic nature of the chelate ring, it is possible to create π–π interactions to its symmetry-related counterpart [3.720 (2) Å] and also with a pyridine ring [3.570 (3) Å] of the bipy unit. The present structure is a redetermination of a previous structure [Vicente et al. (1997 ▶). Private communication (refcode PYCXMN02). CCDC, Cambridge, England]. In the new structure refinement all H atoms were located in a difference Fourier synthesis. Their coordinates were refined freely, together with isotropic displacement parameters.

4,11-Diaza-1,8-diazo­niacyclo­tetra­decane dichloride hemihydrate

In the title compound, C10H26N4 2+·2Cl−·0.5H2O, the cyclam (1,4,8,11-tetraazacyclotetradecane) dication adopts an endodentate conformation which my be inflenced by intramolecular N—H⋯N hydrogen bonding. In the crystal structure, the components are linked by N—H⋯Cl and O—H⋯Cl hydrogen bonds into chains along [100]. The water molecule is disordered over two sites in a 50:50 ratio.

Tetra­chlorido(1,10-phenanthroline-κ2N,N′)platinum(IV) acetonitrile hemisolvate

The asymmetric unit of the title compound, [PtCl4(C12H8N2)]·0.5CH3CN, contains two crystallographically independent PtIV complexes with very similar geometry and one solvent molecule. In the complexes, each PtIV ion is six-coordinated in a distorted octahedral environment by two N atoms of the 1,10-phenanthroline ligand and four Cl atoms. Because of the different trans effects of the N and Cl atoms, the Pt—Cl bonds trans to the N atom are slightly shorter than those trans to the Cl atom. The compound displays numerous intermolecular π–π interactions between six-membered rings, with a shortest centroid-to-centroid distance of 3.654 Å. There are also weak intra- and intermolecular C—H⋯Cl hydrogen bonds.

catena-Poly[hemi(hexane-1,6-diammonium) [[aqua­dibromido­manganese(II)]-μ-pyridine-2-carboxyl­ato]]

The asymmetric unit of the title compound, {(C6H18N2)0.5[MnBr2(C6H4NO2)(H2O)]}n, contains the repeat unit of the complex anion and one-half of a hexane-1,6-diammonium cation that is located on a twofold rotation axis. In the anionic polymer, the Mn2+ ions are bridged by the pyridinecarboxylate (pic) anion ligand, forming a chain structure along the c axis. The Mn2+ ion is six-coordinated in a distorted octahedral environment by one N atom of the pyridine ring, two O atoms of the two carboxylate groups, one O atom of the water molecule and two Br atoms. The compound displays intermolecular N—H⋯O, N—H⋯Br, O—H⋯Br and O—H⋯O hydrogen bonding. There may also be intermolecular π–π interactions between adjacent pyridine rings, with a centroid–centroid distance of 3.992 (4) Å.

Dichloridobis(pyridine-2-carboxyl­ato-κ2N,O)platinum(IV) acetonitrile solvate

The asymmetric unit of the title compound, [PtCl2(C6H4NO2)2]·CH3CN, contains a neutral PtIV complex and an acetonitrile solvent molecule. In the complex, the Pt4+ atom is six-coordinated in a distorted octahedral environment by two N atoms and two O atoms from two pyridinecarboxylate (pic) ligands and two Cl atoms. The Cl atoms are cis with respect to each other. The compound displays inter- and intramolecular C—H⋯O and C—H⋯Cl hydrogen bonding.

4,11-Diaza-1,8-diazo­niacyclo­tetra­decane bis­(pyridine-2-carboxyl­ate) dihydrate

The asymmetric unit of the title compound, C10H26N4 2+·2C6H4NO2 −·2H2O, consists of half of a doubly protonated 1,4,8,11-tetraazacyclotetradecane (cyclam) dication, a pyridine-2-carboxylate anion and a solvent water molecule. The complete dication is generated by a crystallographic centre and adopts an endodentate conformation which may be influenced by intramolecular N—H⋯N hydrogen bonding. The carboxylate group of the anion appears to be delocalized on the basis of the C—O bond lengths [1.257 (2) and 1.250 (2) Å]. In the crystal structure, the components are linked by intermolecular N—H⋯O, N—H⋯N and O—H⋯O hydrogen bonds.

Tetra­chlorido(1,10-phenanthroline-κ2N,N′)platinum(IV) monohydrate

In the title complex, [PtCl4(C12H8N2)]·H2O, the Pt4+ ion is six-coordinated in a distorted octahedral environment by two N atoms of a 1,10-phenanthroline ligand and by four Cl atoms. As a result of the different trans effects of the N and Cl atoms, the Pt—Cl bonds trans to the N atom are slightly shorter than those trans to the Cl atom. The compound displays intermolecular π–π interactions between the six-membered rings, with a centroid–centroid distance of 3.834 Å. There are also weak intramolecular C—H⋯Cl hydrogen bonds. According to the IR spectrum, solvent water was present in the crystal, but owing to the high thermal motion of the uncoordinated O atom, the H atoms could not be detected.

Hexane-1,6-diammonium bis­(pyridine-2-carboxyl­ate)

The title compound, C6H18N2 2+·2C6H4NO2 −, consists of a doubly protonated hexamethylenediammonium dication and two pyridine-2-carboxylate anions. These ions interact by means of intermolecular N—H⋯O and N—H⋯N hydrogen bonds to form a two-dimensional array. The carboxylate groups of the anions appear to be delocalized on the basis of the C—O bond lengths.

Tetra(chlorido/iodido)(1,10-phenanthroline)platinum(IV) hemi[di(chlorine/iodine)].

The asymmetric unit of the title compound, [PtCl3.66I0.34(C12H8N2)]·0.5(Cl0.13I1.87), contains a neutral PtIV complex and one half of a halogen molecule. The PtIV ion is six-coordinated in a distorted octahedral environment by two N atoms of the 1,10-phenanthroline ligand and Cl or I atoms. The refinement of the structure and the EDX analysis indicate that the compound is a solid solution in which there is some substitution of Cl for I and vice versa. The chemical formula of the pure state of the compound would have been [PtCl4(C12H8N2)]·0.5I2. In the analysed crystal, two Cl atoms are partially (ca 25% and 9%) replaced by I atoms, and the I2 molecule has a minor component modelled as ICl. As a result of the disorder, the different trans effects of the N and Cl/I atoms are not distinct. The complex displays intermolecular π–π interactions between the six-membered rings, with a centroid–centroid distance of 3.771 (4) Å. There are also weak intramolecular C—H⋯Cl hydrogen bonds.

Tetra­kis(pyridine-2-carboxyl­ato-κ2N,O)palladium(IV) dihydrate

The asymmetric unit of the title compound, [Pd(C6H4NO2)4]·2H2O, consists of a quarter of a neutral PdIV complex and half of a solvent water molecule. In the complex, the PdIV ion is located on a fourfold inversion axis and eight-coordinated in a distorted dodecahedral environment by four N and four O atoms from four symmetry-related pyridine-2-carboxylate (pic) anionic ligands. In the crystal, the water molecule is involved in O—H⋯O hydrogen bonding, and weak intermolecular C—H⋯O hydrogen bonds occur. There are also intermolecular π–π interactions between adjacent pyridine rings, with a centroid–centroid distance of 3.715 (3) Å.