Chloridobis(dimethyl­glyoximato-κ²N,N′)(ethyl pyridine-3-carboxyl­ate-κN)cobalt(III)

In the title compound, [Co(C₄H₇N₂O₂)₂Cl(C₈H₉NO₂)], which was prepared as a model complex of vitamin B₁₂, the Co^III atom, which is linked to four N atoms of the pseudo-macrocyclic (dmgH)₂ ligand (dmgH is dimethyl­glyoximate) in the equatorial plane and one Cl⁻ anion and one N atom of ethyl nicotinate in apical positions, displays an approximately octa­hedral coordination. The Co atom is 0.0187 (8) Å out of the mean plane of the four equatorial N atoms. The structure has an O...H...O bridge, which is very common in cobaloxime derivatives, with O...H distances of 1.24 (2) and 1.25 (2) Å.

Cyclo­linopeptide B methanol tris­olvate

The title compound, C₅₆H₈₃N₉O₉S·3CH₃OH, is a methanol tris­olvate of the cyclo­linopeptide cyclo(Met¹—Leu²—Ile³—Pro⁴—Pro⁵—Phe⁶—Phe⁷—Val⁸—Ile⁹) (henceforth referred to as CLP-B), which was isolated from flaxseed oil. All the amino acid residues are in an L-configuration based on the CORN rule. The cyclic nona­peptide exhibits eight trans peptide bonds and one cis peptide bond observed between the two proline residues. The conformation is stabilized by an α-turn and two consecutive β-turns each containing a N—H...O hydrogen bond between the carbonyl group O atom of the first residue and the amide group H atom of the fourth (α-turn) or the third residue (β-turns), repectively. In the crystal, the components of the structure are linked by N—H...O and O—H...O hydrogen bonds into chains parallel to the a axis.

Diaqua­bis­[5-(pyrazin-2-yl)-3-(pyridin-4-yl)-1H-1,2,4-triazol-1-ido-κN¹]zinc

The title mononuclear complex, [Zn(C₁₁H₇N₆)₂(H₂O)₂], is composed of one Zn^II ion, two deprotonated ppt ligands [Hppt = 5-(pyrazin-2-yl)-3-(pyridin-4-yl)-1H-1,2,4-triazole] and two coordinating water mol­ecules. The asymmetric unit consists of one half-mol­ecule that is completed by application of a centre of symmetry. The Zn^II atom is six-coordinated in an octa­hedral environment, surrounded by two O atoms in the axial positions and four N atoms in the equatorial plane. Adjacent mononuclear units are further linked via O—H...N hydrogen-bonding inter­actions, forming a two-dimensional network along (100).

Chloridobis(dimethyl­glyoximato-κ²N,N′)(ethyl pyridine-4-carboxyl­ate-κN)cobalt(III) chloro­form monosolvate

The title compound, [Co(C₄H₇N₂O₂)₂Cl(C₈H₉NO₂)]·CHCl₃, was synthesized as a model complex of vitamin B₁₂. The Co^III cation displays an approximately octa­hedral coordination environment, being displaced by 0.0240 (15) Å from the mean plane of the four N atoms of the equatorial plane. The O—H distances in the dimethyl­glyoximate hy­droxy groups are 0.89 (6) and 1.14 (6) Å; such long O—H bonds are very common in cobaloxime derivatives. Weak classical O—H...N and non-classical C—H...Cl hydrogen-bonding interactions further consolidate the crystal packing.

Tetra­aqua­bis­(6-chloro­pyridine-3-carboxyl­ato-κO)nickel(II) tetra­hydrate

In the title compound, [Ni(C₆H₃ClNO₂)₂(H₂O)₄]·4H₂O, the Ni^II ion is located on an inversion centre and is octa­hedrally coordinated by four O atoms from four water mol­ecules in the equatorial plane and two O atoms of two 6-chloro-3-carboxyl­ate ligands in axial positions. There are also four lattice water molecules present. The organic ligands are bound to the Ni^II ion in a monodentate manner through a carboxyl­ate O atom. There is one strong intra­molecular O—H...O hydrogen bond and six inter­molecular O—H...O and O—H...N hydrogen-bonding inter­actions in the packing, resulting in a complex three-dimensional network structure.

Tetra­aqua­bis­(6-chloro­pyridine-3-carboxyl­ato-κO)cobalt(II) tetra­hydrate

In the title compound, [Co(C₆H₃ClNO₂)₂(H₂O)₄]·4H₂O, the Co^II cation is located on an inversion center and is coordinated by four water mol­ecules and two 6-chloro­pyridine-3-carboxyl­ate anions in a slightly distorted octa­hedral geometry. In the crystal, complex mol­ecules and lattice water mol­ecules are linked by O—H...O and O—H...N hydrogen bonds into a three-dimensional network.

catena-Poly[[[diaqua­copper(II)]-μ-quinoline-2,3-dicarboxyl­ato-κ³N,O²:O³] monohydrate]

In the title compound, {[Cu(C₁₁H₅NO₄)(H₂O)₂]·H₂O}_n, the Cu^II ion is five-coordinated by two O atoms and one N atom of two symmetry-related quinoline-2,3-dicarboxyl­ate ligands, and two water mol­ecules. The water mol­ecules occupy basal and apical positions of the square-pyramidal coordination polyhedron. Each quinoline-2,3-dicarboxyl­ate dianion bridges two adjacent Cu^II ions, forming a polymeric chain along [010]. The chains are further connected via O—H...O hydrogen-bonding inter­actions and quinoline ring π–π inter­actions [centroid–centroid distance = 3.725 (4) Å], generating a three-dimensional structure. Lattice water mol­ecules participate in the crystal structure via O—H...O hydrogen bonds.

[5-(Pyridin-2-yl)-1H-tetra­zole-κ²N⁴,N⁵]bis(triphenyl­phosphane-κP)copper(I) tetra­fluoridoborate

In the title Cu^I compound, [Cu(C₆H₅N₅)(C₁₈H₁₅P)₂]BF₄, the Cu^I cation is N,N′-chelated by a 5-(pyridin-2-yl)-1H-tetra­zole ligand and coordinated by two triphenyl­phosphane ligands in a distorted tetra­hedral geometry. The tetra­zole and pyridine rings are essentially coplanar [dihedral angle = 4.1 (3)°]. The tetra­fluoridoborate anion links to the complex cation via an N—H...F hydrogen bond.

(E)-1-[4-(3-Bromo­prop­oxy)phen­yl]-2-p-tolyl­diazene

In the title mol­ecule, C₁₆H₁₇BrN₂O, the benzene rings, bridged by a diazene fragment, form a dihedral angle of 6.3 (2)°. The crystal packing exhibits relatively short Br...Br contacts of 3.6989 (14) Å.

6′-Amino-3′-methyl-11H,2′H-spiro­[indeno­[1,2-b]quinoxaline-11,4′-pyrano[2,3-c]pyrazole]-5′-carbonitrile ethanol monosolvate

In the title spiro­indeno­quinoxaline compound, C₂₂H₁₄N₆O·C₂H₆O, the five-membered ring of the indene unit and the pyran ring are perpendicular [89.11 (3)°]. In the crystal, N—H...N hydrogen bonds connect the spiro­indeno­quinoxaline mol­ecules, and the ethanol solvent mol­ecules complete the hydrogen-bond network via O—H...N and N—H...O inter­actions.