Nobuo Okabe

Bis(μ-pyridine-2,6-carboxyl­ato-O,N,O′:O)­bis­[tri­aqua­manganese(II)]–pyridine-2,6-di­carboxylic acid (1/2)

In the structure of the title compound, [Mn(2)(C(7)H(3)NO(4))(2)(H(2)O)(6)].2C(7)H(5)NO(4), a centrosymmetric dinuclear complex, hexaaaquabis(pyridine-2, 6-dicarboxylato)dimanganese(II) and free pyridine-2,6-dicarboxylic acid are present in a 1:2 ratio. In the complex, each Mn(2+) ion is coordinated by three O atoms and one N atom from the pyridine-2, 6-dicarboxylate ligands and by three water O atoms, resulting in a distorted pentagonal bipyramidal coordination. Within the centrosymmetric dinuclear complex, two Mn(2+) ions are bridged by two carboxylate O atoms. The crystal structure is stabilized by hydrogen bonds involving all the H atoms of the water ligands.

Aqua­bis­(quinoline-2-carboxyl­ato-κ2N,O)­zinc(II)

In the title compound, [Zn(C10H7NO3)2(H2O)], the Zn atom is pentacoordinated and has a square pyramidal geometry. The Zn atom is coordinated by two N and two O atoms of the two organic ligands, forming the square plane. One aqua O atom occupies the vertex of the square pyramid. The N and O atoms of the ligands lie in trans positions with respect to each other.

Separation of metallothionein isoforms of mouse liver cytosol by capillary zone electrophoresis

Metallothionein (MT) isoforms of mouse liver cytosol were separated by capillary zone electrophoresis (CZE) using a polyacrylamide-coated tube at neutral pH, samples prepared from non-treated, heat-treated, and ethanol-precipitated specimens were compared. The liver was homogenized in three kinds of media, 0.25 M sucrose containing 100 mM Tris-HCl buffer at pH 7.4 (BS), BS containing 1% ascorbic acid (BS-C), and BS containing 5 mM beta-mercaptoethanol (BS-M). Mouse liver was used 24 h after subcutaneous injection of 50 mg Zn kg(-1). In the non-treated specimen of the cytosol fraction, the MT-2 isoform was separated in all three media, while the MT-1 isoform was difficult to identify. In the ethanol-precipitated specimen, MT isoforms were separated well using either BS or BS-C. However, when BS-M was used, a small MT-2 peak was obtained the MT-1 peak could not be identified. MT-1 isoform in the heat-treated specimen was difficult to identify. In contrast, MT-2 isoform was separated well in all three kinds of media. In the non-treated specimen of the control liver cytosol, the MT-2 isoform was detected using all three media, the MT-1 peak was undetected. Based on these results, MT isoforms can be detected in the crude cytosol fraction of liver using CZE combined with a polyacrylamide-coated tube at neutral pH.

fac‐Tris(2‐ethyl‐4‐oxo‐4H‐pyran‐3‐olato‐κ2O3,O4)­iron(III) and its aluminium(III) analog

The crystal structures of the title iron(III) and aluminium(III) ethyl maltolate complexes, [Fe(C(7)H(7)O(3))(3)] and [Al(C(7)H(7)O(3))(3)], respectively, are isomorphous. In each case, the three bidentate ligand molecules are bound to the metal atom, forming a distorted octahedral coordination geometry in a fac configuration.

8-Hydroxyquinaldinic acid and its nickel(II) complex

The molecules of 8-hydroxyquinolinium-2-carboxylate, C(10)H(7)NO(3), have a planar structure, in which the carboxyl group is ionized and the ring N atom is protonated. The derived nickel(II) complex, bis(8-hydroxyquinoline-2-carboxylato-kappa(3)O(2),N,O(8))nickel(II) trihydrate, [Ni(C(10)H(6)NO(3))(2)].3H(2)O, contains an octahedral central Ni(II) ion coordinated by the hydroxyl O atom, the ring N atom and the carboxylate O atom of each of the two tridentate ligands, with a perpendicular orientation of the quinoline rings.

Cobalt(II), nickel(II) and copper(II) complexes of isoquinoline-3-carboxylate.

The crystal structures of the title complexes, namely trans-bis(isoquinoline-3-carboxylato-kappa2N,O)bis(methanol-kappaO)cobalt(II), [Co(C10H6NO2)2(CH3OH)2], and the corresponding nickel(II) and copper(II) complexes, [Ni(C10H6NO2)2(CH3OH)2] and [Cu(C10H6NO2)2(CH3OH)2], are isomorphous and contain metal ions at centres of inversion. The three compounds have the same distorted octahedral coordination geometry, and each metal ion is bonded by two quinoline N atoms, two carboxylate O atoms and two methanol O atoms. Two isoquinoline-3-carboxylate ligands lie in trans positions, forming the equatorial plane, and the two methanol ligands occupy the axial positions. The complex molecules are linked together by O-H...O hydrogen bonds between the methanol ligands and neighbouring carboxylate groups.

Cobalt(II) and nickel(II) complexes of quinoline-2-carboxylate.

The title complexes, trans-diaquabis(quinoline-2-carboxylato-kappa(2)N,O)cobalt(II)-water-methanol (1/2/2), [Co(C(10)H(6)NO(2))(2)(H(2)O)(2)].2CH(4)O.2H(2)O, and trans-diaquabis(quinoline-2-carboxylato-kappa(2)N,O)nickel(II)-water-methanol (1/2/2), [Ni(C(10)H(6)NO(2))(2)(H(2)O)(2)].2CH(4)O.2H(2)O, are isomorphous and contain Co(II) and Ni(II) ions at centers of inversion. Both complexes have the same distorted octahedral coordination geometry, and each metal ion is coordinated by two quinoline N atoms, two carboxylate O atoms and two water O atoms. The quinoline-2-carboxylate ligands lie in trans positions with respect to one another, forming the equatorial plane, with the two water ligands occupying the axial positions. The complex molecules are linked together by hydrogen bonding involving a series of ring patterns which include the uncoordinated water and methanol molecules.

Imidazole-4-acetic acid monohydrate

D), with their individual centroids at (0.738,0.180,-0.381), (1.154,0.855,-0.108), (0.712,0.684,0.627) and (0.202,0.358, -0.122), respectively. The molecules are in two pairs (A/C and B/D) and the relationship within a pair is close to a shift of 0.5 along the b axis. However, halving the b axis is not likely since the reflections with k odd are not weak, and the orientations of the methoxycarbonyl groups at C5 and C6 are significantly different within each pair. Data collection: SMART (Siemens, 1996). Cell refinement: SAINT (Siemens, 1996). Data reduction: SAINT. Program(s) used to solve structure: SHELXTL (Sheldrick, 1997). Program(s) used to refine structure: SHELXTL. Molecular graphics: SHELXTL. Software used to prepare material for publication: SHELXTL and PARST (Nardelli, 1995).

catena-Poly­[[(1,10-phenanthroline-κ2N,N′)silver(I)]-μ-chloro]

In the title compound, [AgCl(C12H8N2)]n, the Ag atom is four-coordinate in a highly distorted tetrahedral environment formed by two N atoms of phenanthroline and two Cl atoms. The Ag atoms are bridged by Cl atoms and the compound forms a one-dimensional polymer. Ag and Cl atoms lie on twofold rotation axes.

catena-Poly­[[[aqua(2-methyl-4-oxo-4H-pyran-3-olato-κO3,O4)copper(II)]-μ-chloro] monohydrate]

In the title complex, {[Cu(C6H5O3)Cl(H2O)]·H2O}n, the CuII atom has a deformed square-pyramidal coordination geometry formed by two O atoms of the maltolate ligand, two bridging Cl atoms and the coordinated water O atom. The Cu atoms are bridged by Cl atoms to form a polymeric chain. The deprotonated hydroxyl and ketone O atoms of the maltolate ligand form a five-membered chelate ring with the Cu atom. Stacking interactions and hydrogen bonds exist in the crystal.