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.

Bis[μ-N-(diethyl­amino-κN)dimethyl­silylanilido-κ²N:N]bis­[chlorido­cobalt(II)]

In the title binuclear Co^II complex, [Co₂(C₁₂H₂₁N₂Si)₂Cl₂], an inversion center is located at the mid-point between the two Co atoms in the dimeric mol­ecule. The bidentate N-silylated anilide ligand coordinates the Co^II atom in an N,N′-chelating mode and provides the anilide N atom as a bridge to link two Co^II atoms. The two ends of the N—Si—N chelating unit exhibit different affinities for the metal atom. The Co—N_anilide bond is 2.031 (6) Å and Co—N_amino bond is 2.214 (6) Å. The four-coordinate Co atom presents a distorted tetra­hedral geometry, while the dimeric aggregation exhibits a (CoN)₂ rhombus core with 1.998 (6) Å as the shortest sides and shows a ladder structure composed of Co, N and Si atoms.

Bis[4-amino-3,5-bis­(pyridin-2-yl)-4H-1,2,4-triazole-κ²N²,N³]bis­(benzene-1,2-dicarb­oxy­lic acid-κO)copper(II) bis­(2-carb­oxy­benzoate)

In the complex cation of the title salt, [Cu(C₁₂H₁₀N₆)₂(C₈H₆O₄)₂](C₈H₅O₄)₂, the Cu^II atom, lying on an inversion center, exhibits a distorted octa­hedral geometry defined by four N atoms from two 4-amino-3,5-bis­(pyridin-2-yl)-4H-1,2,4-triazole ligands in the equatorial plane and two axial O atoms from two benzene-1,2-dicarb­oxy­lic acid ligands. In the crystal, the complex cations and the monodeprotonated 2-carb­oxy­benzoate anions are connected by O—H...O and N—H...O hydrogen bonds, forming a tape along [100]. Adjacent tapes are further linked into a three-dimensional arrangement via π–π stacking inter­actions between the triazole and benzene rings and between the pyridine and benzene rings [centroid–centroid distances = 3.6734 (14)/3.9430 (16) and 3.8221 (14) Å]. Intra­molecular N—H...N and O—H...O hydrogen bonds are also observed.

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.

(E)-3-(4-Chloro­phen­yl)-1-(5-hy­droxy-2,2-dimethyl-2H-chromen-6-yl)prop-2-en-1-one

There are two independent mol­ecules in the asymmetric unit of the title compound, C₂₀H₁₇ClO₃, each having an E configuration about the –C=C– bond. The dihedral angles between the two benzene rings in the two mol­ecules are 7.17 (11) and 9.82 (11)°. In both mol­ecules, the hy­droxy group is involved in an intra­molecular O—H...O hydrogen bond.

Bis{N-[(diethyl­amino)­dimethyl­sil­yl]anilinido-κ²N,N′}nickel(II)

The mononuclear Ni^II amide, [Ni(C₁₂H₂₁N₂Si)₂], has the Ni^II atom N,N′-chelated by the N-silylated anilinide ligands. The ligands are arranged cis to each other and obey the C₂-symmetry operation. The two ends of the N—Si—N chelating unit exhibit different affinities for the metal atom: the Ni—N_anilinide bond length is 1.913 (3) Å and Ni—N_amine is 2.187 (3) Å. The four-coordinate Ni^II ion demonstrates a distorted tetra­hedral geometry.

Diaqua­bis­[5-(pyrazin-2-yl-κN¹)-3-(pyridin-4-yl)-1H-1,2,4-triazol-1-ido-κN¹]cobalt(II) methanol disolvate

The Co^II ion in the title mononuclear compound, [Co(C₁₁H₇N₆)₂(H₂O)₂]·2CH₃OH, is located on an inversion center and is six-coordinated in a distorted octa­hedral geometry defined by four N atoms from two deprotonated 5-(pyrazin-2-yl-κN)-3-(pyridin-4-yl)-1H-1,2,4-triazol-1-ide (ppt) ligands and two water mol­ecules. In the crystal, the complex mol­ecules and lattice methanol mol­ecules are linked via O—H...N and O—H...O hydrogen bonds, generating a two-dimensional supra­molecular network parallel to (001). π–π inter­actions between the triazole and pyrazine rings and between the pyridine rings are present [centroid–centroid distances = 3.686 (3) and 3.929 (4) Å, respectively].

Poly[(acetato-κ²O,O′)aqua­(μ₄-1H-benzimidazole-5,6-dicarboxyl­ato-κ⁶N³:O⁵,O^5′:O⁵,O⁶:O^6′)cerium(III)]

In the title compound, [Ce(C₉H₄N₂O₄)(C₂H₃O₂)(H₂O)]_n, the Ce^III ion is coordinated by five O atoms and one N atom from four 1H-benzimidazole-5,6-dicarboxyl­ato (L) ligands and by two O atoms from an acetate ligand and one aqua ligand, forming a slightly distorted tricapped trigonal–prismatic geometry. The L ligands are bridging, forming a layered polymer parallel to (010). In the crystal, O—H...O and N—H...O hydrogen bonds connect the polymer layers into a three-dimensional network.

Chlorido{N-[(diethyl­amino)­dimethyl­sil­yl]anilido-κN}(N,N,N′,N′-tetra­methyl­ethane-1,2-diamine-κ²N,N′)iron(II)

In the title iron(II) complex, [Fe(C₁₂H₂₁N₂Si)Cl(C₆H₁₆N₂)], the Fe^II cation is coordinated by two N atoms from the tetramethylethane-1,2-diamine ligand [Fe—N = 2.191 (5) and 2.215 (4) Å], one N atom from the N-[(diethyl­amino)­dimethyl­sil­yl]anilide ligand [Fe—N = 1.943 (4) Å] and a chloride ligand [Fe—Cl = 2.2798 (16) Å] in a distorted tetra­hedral geometry. The N—Si—N angle is 113.9 (3)°. The crystal packing exhibits no short inter­molecular contacts.

Bis[μ-N-(tert-butyl­dimethyl­sil­yl)quinolin-8-aminato-1:2κ²N¹,N⁸:N⁸](N,N,N′,N′-tetra­methyl­ethane-1,2-diamine-1κ²N,N′)lithiumsodium

In the heterometallic title bulky amido complex, [LiNa(C₁₅H₂₁N₂Si)₂(C₆H₁₆N₂)], both alkali metal ions are four-coordinated with distorted tetra­hedral geometries. The Li⁺ ion is N,N′-chelated by the N-silylated amido ligand, with Li—N = 2.015 (5) and 2.074 (5) Å. The two amido ligands are arranged cis to each other. The mol­ecule exhibits a twofold rotational symmetry operation along the Li–Na axis. The Na⁺ ion is coordinated by two N atoms from the tetra­methyl­ethylenediamine ligand [Na—N = 2.553 (4) Å] and shares two amido N atoms from the N-silylated amido ligands with the Li⁺ ion. Although the crystal structure contains voids with an approximate volume of 50 ų there is no inclusion of solvent mol­ecules.