Synthesis and crystal structures of the Zn(II) and Co(II) complexes containing the reduced derivative nitronyl nitroxide

Two complexes of formulas [Zn(Hfac)₂(IM-IMH-Bph)] (I) and [Co(Hfac)₃](IM-Bph) (II), where IM-Bph = 2,2′-bis(1′-oxyl-4′,4′,5′,5′-tetramethylimidazoline-2′-yl)-bis(2-formylphenyl) ether; Hfac = hexafluoroacetylacetonate, have been synthesized and characterized by single-crystal X-ray diffraction. The X-ray analysis demonstrates that both I and II are mononuclear complexes. In I, each zinc ion is five-coordinated with four oxygen atoms from two Hfac ligands and one oxygen atom from nitroxide. Complex II contains one Co(III) atom with six oxygen atoms from three Hfac ligands and uncoordinated IM-Bph diradical, in which the Co²⁺ ion and NIT-Bph biradical can undergo the redox reaction.     

Syntheses, crystal structures, and magnetic properties of two monometallic tri-spin complexes involving nitronyl nitroxide radicals-lanthanide ions

Two new lanthanide-radical complexes [Ln(Hfac)₃(NIT-4PhAllO)₂](Ln(III) = Gd (I), Tb (II); Hfac = hexafluoroacetylacetonate; NIT-4PhAllO = 4′-allyloxyphenyl-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide) have been prepared and characterized in structurally as well as magnetically. Single crystal X-ray diffraction analyses reveal that two complexes are isostructural with mononuclear tri-spin structure, in which the metal ions are eight-coordinated in distorted dodecahedron geometry. The nitronyl nitroxide radicals act as monodentate ligands towards Ln(Hfac)₃ unit through the oxygen atom of the nitronyl nitroxide group. Magnetic studies reveal that the Gd-coordinated nitroxide interaction is ferromagnetic.     

Cyclometallated iridium(III) complex with the norbornene-substituted pyrazolonate ligand and related copolymers: syntheses, structures, and photophysical properties

New cyclometallated iridium(III) complex (NBEpz)Ir(Ppy)₂ · 2CH₂Cl₂ (I) (NBEpzH is 1-phenyl-3-methyl-4-(5-bicyclo[2.2.1]hept-5-en-2-yl)-5-pyrazolone, PpyH is 2-phenylpyridine) is synthesized and structurally characterized. Compound I undergoes metathesis polymerization and forms new iridium-containing copolymers. The photophysical properties of complex I and related copolymers are studied.     

Heterometallic complexes of macrocyclic oxamide with polycarboxylates: Syntheses,crystal structures,and magnetic properties

Three complexes with the formula [Co(Ip)(CuL)(H₂O)₂] · H₂O (I), [Co(Ip)(NiL)(H₂O)₂] · H₂O (II), [Co(CuL)₂(Hbtc)(H₂O)] (III), (H₂Ip = m-isophthalic acid; H₂L = 2,3-dioxo-5,6,14,15-dibenzo-1,4,8,12-tetraazacyclo-pentadeca-7,13-dien; H₃Btc = 1,3,5-benzenetricarboxylic acid) were synthesized and structurally characterized by elemental analysis, IR and UV spectroscopy. Single-crystal X-ray analyses reveal that the complexes I and II contain neutral heterometallic binuclear CoM (for I and II, M = Cu, Ni, respectively) moieties, and complex III contains discrete neutral trinuclear CoCu₂ moieties. The structures of I–III consist of two-dimensional supramolecular architecture formed by strong O-H…O intermolecular hydrogen bonds. Furthermore, the magnetic properties of complex I were investigated and discussed in detail.     

Hydrothermal synthesis, crystal structure of three novel complexes based on thiabendazole and 1,4-benzenedicarboxylate ligands

Three novel metal-organic complexes [Co(BDC)(TBZ)₂] (I), [Cd₂(BDC)₂(TBZ)₂(H₂O)₂] · 2(H₂O) (II), [Mn₂(BDC)(TBZ)₄(SO4)] (III) (BDC = 1,4-benzenedicarboxylate, TBZ = thiabendazole) have been prepared and characterized by IR spectrum, elemental analysis, thermogravimetric analysis, and single-crystal X-ray diffraction. X-ray structure analysis reveals that both three complexes are one-dimensional chain polymers. The 1D chain architecture of I is constructed from terephthalic acid and cobalt atoms. A simultaneous presence of chelating and monodentate coordination modes of BDC ligands is observed in complex II. In complex III, the coordinated BDC ligands adopt monodentate mode and with SO ₄ ^2? anions alternately bridge the Mn²⁺ ions into 1D chains. The 3D structures of the three complexes are stabilized by π-π stacking interactions and hydrogen-bonds.     

Crystal structures and luminescence of a series of cadmium(II) complexes based on isophorone derivative containing imidazolyl

Three new complexes, [CdL₂(CH₃COO)₂(H₂O)₂] (I), CdL₂Br₂ (II), CdL₂I₂ (III), have been successfully synthesized by self-assembly of corresponding metal salts with (E)-2-(3-(4-(1H-imidazole-1-yl)styryl)-5,5-dimethylcyclohex-2-enylidene)malononitrile (L). The structures of the complexes were determined by single crystal X-ray diffraction analysis (CIF file CCDC nos. 957831 (I), 957792 (II), 957832 (III)). In complex I, central metal is six-coordinated and the crystal packing shows a 3D supramolecular framework. Complexes II and III display the similar 2D supramolecular structures in which the central metals are four-coordination. The luminescent properties were investigated.     

New Ni(II) and Co(II) coordination compounds construction from the ditopic 1,2,3-triazol-based aromatic heterocyclic polycarboxylic ligand

Mononuclear compound I ([Co(Ptia)₂(H₂O)₄] ? H₂O) and 1D chain compound II ([Ni₄(Cptia)₄(H₂O)₁₂]_∞) have been constructed from the new ditopic 1,2,3-trazol-based aromatic heterocyclic carboxylic ligand, 4-(4-carboxy-1H-1,2,3-triazol-1-yl) benzoic acid) (H₂Cptia), under different pH conditions by using the hydrothermal method. Their structure was characterized by single crystal X-ray diffraction (СIF files CCDC nos. 1409531 (I) and 1409531 (II)), IR spectra, and elemental analysis. Compound I is a mononuclear compound. In II, two sets of parallel arrangement 1D chains orient in different directions. The results of their magnetic measurements display the antiferromagnetic interaction exists among the paramagnetic ions.     

Structural diversity of two novel complexes of Co(II) with bis-triazole ligand: From one-dimensional chain to two-dimensional porous network

Using two novel bis-triazole ligands, 2,6-bis(1,2,4-triazole-4-yl)pyridine (L¹) and 1,6-bis(1,2,4-triazole-1-yl)hexane (L²), one novel one-dimensional (1D) chain polymer [Co(NCS)₂(L¹)₂] _n (I) and one two-dimensional (2D) coordination polymer [Co(NCS)₂(L²)₂] _n (II) have been synthesized and structurally characterized. The crystal crystallizes in the triclinic system for I, space group $P\bar 1$ , a = 7.879(6), b = 8.830(7), c = 9.837(8)Å, α = 70.230(11)°, β = 115.474(6)°, γ = 85.591(12)°, Z = 1. The crystal crystallizes in the mo-noclinic system for II, space group $P\bar 1$ , a = 7.879(6), b = 8.830(7), c = 9.837(8) α = 70.230(11)°, β = 115.474(6)°, γ = 85.591(12)°, Z = 1. The structural diversity of these two new Co(II) complexes vary from 1D chain to 2D porous supramolecular network, which may be ascribed to ligand directing effects under similar synthetic conditions (L¹ contains rigid pyridine spacers while L2 contains flexible hexane spacers).     

Hydrothermal synthesis, crystal structures, and properties of two Co(II) complexes based on 4-bromoisophthalic acid and N-donor ligands

Two new Co(II) complexes, [Co₂(H₂O)(Bipy)₂(Bript)₂] _n (I) and [Co(H₂O)(Phen)(Bript)] · H₂O (II), where H₂Bript = 4-bromoisophthalic acid, Bipy = 2,2??-bipyridine, and Phen = 1,10-phenanthroline, have been synthesized and characterized by elemental analysis, IR, and single-crystal X-ray diffraction. Complex I has binuclear units in which two Co²⁺ ions are bridged by two carboxylate groups and a coordinaiod-water molecule, and the binuclear units are connected by Bript to generate a 1D helical chain. These 1D helical chains are further linked by ????? stacking interactions to form a 3D supramolecular network, while complex II has a 2D layer motif. In I and II, there exists extensive hydrogen bonding interactions. The thermal behavior of the two corresponding complexes have briefly been investigated.     

Solvothermal synthesis,crystal structure,and characterization of two new 2D Co(II)/Ni(II) coordination polymers with mixed-organic tectonics

Two new isomorphous coordination polymers [Co(4,4′-Bpda)(Dpa)] _n (I) and [Ni(4,4′-Bpda)(Dpa)] _n · H₂O (II) (4,4′-H₂Bpda = benzophenone-4,4′-dicarboxylic acid, Dpa = dipyridin-4-ylamine) were synthesized under solvothermal condition and characterized by elemental analysis, FT-IR and single-crystal X-ray diffraction technique. Compounds I and II exhibit 2D helical layers resulting from alternating single helical chains and double helical chains, which feature uninodal 4-connected topology with a point symbol of 6⁶.     

Three one-dimensional chains with bulky backbone carboxylate ligands: Syntheses,crystal structures,and luminescent properties

To explore the influence of bulky backbone on complexes, three Co(II) and Zn(II) complexes with phenanthrene-9-carboxylate (L¹), 9H-fluorene-9-carboxylate (L²) or biphenyl-4-carboxylate (L³) together with incorporating auxiliary bridging ligad 4,4′-bipyridine (4Bipy), were synthesized and characterized: [Co(L¹)₂(4Bipy)(H₂O)₂]_∞ (I), [Zn(L²)₂(4Bipy)_0.5(4Bipy)_0.5]_∞ (II), and [Zn₃(L³)₄(4Bipy)_0.5(4Bipy)_0.5(4Bipy)_0.5(OH)₂]_∞ (III). X-ray single-crystal diffraction analyses show that complexes I–III both assume one-dimensional (1D) structures by incorporating the bridging 4Bipy (CIF file CCDC nos. 942729 (I), 942727 (II), and 942733 III). In I, mononuclear six-coordinated Co²⁺ ions are linked into a 1D linear chain by 4Bipy. While in II, mononuclear four-coordinated Zn²⁺ ions are linked into a 1D zigzag chain by 4Bipy. But in III, because of the existence of OH^?, hexanuclear Zn(II) can be regarded as a node, then bridge adjacent hexanuclear Zn(II) nodes by almost parallelled three 4Bipy ligands into a 1D linear chain. Finally the 1D chains of I–III are further assembled into an overall three-dimensional (3D) framework via intermolecular H-bonding, π…π stacking, and/or C-H…π supramolecular interactions, respectively. The results indicate that, besides different metal ions Co²⁺ and Zn²⁺ or OH^? anions, the steric hindrance of backbone ligands play an important role in the formation of I–III. Moreover, the luminescent properties of corresponding ligands and their complexes were briefly investigated.     

Synthesis, crystal structure, and thermal decomposition of two Co(II) complexes with NNN pyrazolyl type ligand and pseudo-halogen

The Co(II) complexes I and II were prepared in nonaqueous solvents containing cyanate with pyrazolylpyridine ligands, namely, bis-2,6-(pyrazol-1-yl) pyridine (Pp) and bis-2,6-(3,5-dimethyl-pyrazol-1-yl) pyridine (Dmpp), respectively. These complexes were characterized with elemental analysis, IR spectroscopy, and X-ray diffraction techniques. X-ray diffraction study revealed that complex I was mononuclear and complex II was dinuclear and ionic. The ionic complex II has an octahedral cationic coordination sphere and a tetrahedral anionic coordination sphere. Thermogravimetry results showed that the thermal decomposition is starting with the carbon content of the pyrazolyl rings.     

Syntheses, structures, and properties of the Co(II), Ni(II), and Cu(II) complexes with 5-carboxy- and 5-methoxycarbonylpyrazoles

New cobalt(II), nickel(II), and copper(II) complexes based on 5-methoxycarbonyl-3-me-thylpyrazole (MePzCOOMe), [Co(MePzCOOMe)₂(H₂O)₂](NO₃)₂ (I), [Ni(MePzCOOMe)₂(H₂O)₂] (NO₃)₂ (II), and [Cu(MePzCOO)₂(H₂O)] · 3H₂O (III), were synthesized. The compounds were studied by X-ray diffraction analysis, IR spectroscopy, and static magnetic susceptibility. The molecular and crystal structures of complexes I and III were determined by X-ray structure analysis.     

Dipyridyl-type ligand-directed assembly of three cobalt(II) coordinated polymers based on carboxyphenylpropionate

A series of Co(II)-H₂Cpp coordination polymers incorporating different auxiliary ligands, [Co(Cpp)(Phen)(H₂O)] (I), {[Co(Bipy)(H₂O)₄](Cpp)} _n (II), and [Co(Cpp)(Bds)(H₂O)] _n (III) (H₂Cpp = 3-(4-carboxyphenyl)propionic acid, Phen = 1,10-phenanthroline, Bipy = 4,4′-bipyridyl, and Bds = 4,4′-bipyridyl sulfide), were synthesized by the hydrothermal reaction and characterized by single crystal X-ray diffraction, elemental analysis, IR, and TG. Three complexes display from 0D to 1D different structural features under the regulation of distinguishing dipyridyl-type coligands. Complex I possesses a binuclear Co(II) motif constructed by H₂Cpp and Phen, which further developing a zipper-like 2D layer via H-bonded and π-π stacking interactions. Complex II displays straight Bipy-bridging 1D chain, and further forming a 3D supramolecular structure by hydrogen-bonded interactions. Complex III exhibits 1D double-chain collectively jointed by Cpp and Bds, which further interlinked into a 3D supramolecular architecture by H-bonded interactions.     

Syntheses, crystal structures and properties of three novel coordination polymers with tripodal imidazole-containing ligands and benzenetetracarboxylate

Three novel coordination polymers, [Ni₂(tib)₂(btec)]·2H₂O (1), [Co₂(tib)₂(btec)]·2H₂O (2) and [Zn₄(tib)₂(btec)Cl₄]·2H₂O (3), have been synthesized by using mixed ligands of 1,3,5-tris(1-imidazolyl)benzene (tib) and 1,2,4,5-benzenetetracarboxylic acid (H4btec) under hydrothermal conditions. Complexes 1 and 2 have the same structure and are rare three-dimensional (3D) self-penetrating (3,4,5)-connected nets, while complex 3 is an unprecedented (3,4)-connected 3D net. The different structures of 1 (2) and 3 are ascribed to the distinct coordination geometry of the metal centers. The thermal stability and photoluminescence property of the complexes were investigated.     

Infinite 1D water chains present in complexes of Co(II) and Zn(II) with 4,4′,6,6′-tetramethyl-2,2′-bipyrimidine

Two new transition metal complexes [Co(tmbpm)Cl₂(H₂O)]·2H₂O (1) and [Zn(tmbpm)Cl₂]·2H₂O (2) (where tmbpm = 4,4′,6,6′-tetramethyl-2,2′-bipyrimidine) are synthesized and characterized by IR and single crystal X-ray diffraction. The tmbpm adopts chelating coordination mode in the two mononuclear complexes. Both 1 and 2 form 2D supramolecular structures containing an infinite 1D water chain through hydrogen bonds.     

Tansition metal complexes with 2-(1-(carboxymethyl)-2-methyl-1H-benzimidazol-3-ium-3-yl)acetate (HL): Synthesis and crystal structure of [Co(L)2(H2O)4] · 6H2O and [Cu(L)2(H2O)2] · 4H2O

Transition metal complexes of 2-(1-(carboxymethyl)-2-methyl-1H-benzimidazol-3-ium-3-yl)acetate (HL), namely [Co(L)₂(H₂O)₄] · 6H₂O (I) and [Cu(L)₂(H₂O)₂] · 4H₂O (II), have been synthesized by a hydrothermal procedure and characterized by X-ray crystallography, CIF files CCDC nos. 1007524 (I), 1007525 (II). Both I and II are mononuclear molecules. In I, the Co²⁺ ion is in octahedral coordiantion environment and surrounded by four O atoms from water molecules and two carboxylate O atoms of two deprotonated ligand (L^?) occupied six culmination. While in II, the Cu²⁺ ion is located in a square-planar geometry, bounded to two aqua O atoms and two carboxylate O atoms from L^?.     

Synthesis, crystal structures and antibacterial activities of schiff base ligand and its cobalt(II) complex

The Schiff base ligand, HL · 0.5C₂H₅OH (HL = methyl N-[(4-chlorophenyl)(3-methyl-5-oxo-1-phenyl-4,5-dihydro-1H-pyrazol-4-ylindene)methyl]valine), was derived from condensation of 1-phenyl-3-methyl-4-(p-chlorbenzyl)-5-pyrazolone with L-valine methyl ester in a 1: 1 molar ratio in methanol, ether and isopropanol solution. Reaction of ligand with Co(ClO₄)₂ · 6H₂O (in a 2: 1 molar ratio) in methanol solution afforded a mononuclear cobalt(II) complex, [Co(L)₂] (I). Molecular structures of HL · 0.5C₂H₅OH and complex I were characterized by elemental analysis, IR and single crystal X-ray diffraction analysis. The enamine-keto form of the ligand has turned to imine form in complex I. Each Co(II) center in complex I is in a octahedral N₂O₄ coordination sphere. Both the Schiff base ligand and its Co(II) complex have been tested in vitro with agar dilution method to evaluate their antibacterial activity against bacteria Escherichia coli and Staphylococcus aureus. It has been found that they have higher activity against Escherichia coli than Staphylococcus aureus, and complex I has higher activity than HL · 0.5C₂H₅OH against the same bacteria.     

Co(II) and Ni(II) complexes with imidazole-containing ligands: Synthesis,structural characterization,and magnetic property

Hydrothermal reaction of Co(II) salt with 1,4-di(1-imidazolyl)benzene (L¹) and 4,4’-oxydiphthalic acid (H₄OA) yields a new complex [Co₃(HOA)₂(L¹)₄(H₂O)₄] (I). [Ni(L²)₂SO₄] · 0.5H₂O (II) can be obtained via the hydrothermal reaction of NiSO₄ · 6H₂O with 1,3-di(1H-imidazol-4-yl)benzene (L²). Complexes I and II have been characterized by single-crystal and powder X-ray diffraction (CIF files CCDC nos. 1019291 (I) and 1019292 (II)), IR, elemental, and thermogravimetric analyses. Complex I exhibits the uninodal six-connected 3D pcu framework structure of I with (4¹² · 6³) topology; Complex II consists of the uninodal four-connected 2D sql (4⁴ · 6²) networks. In addition, magnetic property of I was investigated.     

3,6-Dialkyl-1-phenyl-6-phenylazo-1,4,5,6-tetrahydropyridazine, (4+2)-Cycloadditionsprodukte aus 2-Phenylazo-1-alkenen, 2. Teil: Reaktionen

Catalytic hydrogenation of 3.6-dialkyl-1-phenyl-6-phenylazo-1.4.5.6-tetrahydropyridazines2 a-e gives crystalline bisphenylhydrazones of 1.4-diketones4 a-e; in solution,4 exists as a mixture of geometrical isomers due to the two phenylhydrazone functions. Reaction of2 a-f with H₂NOH yields the dioximes of 1.4-diketones5 a-f. On acid hydrolysis of2, the 6-phenylazo substituent undergoes some reactions and yields products typical of the intermediate “zwitterionic” phenyldiazene. Thus, the tetrahydropyridazine part of2 d yields 1-anilino-2.5-diisopropyl-pyrrole (9), that of2 e gives 2.2.7.7-tetramethyl-3.6-octanedione monophenylhydrazone (10) which undergoes ready oxidation to 3.6-di-t-butyl-6-phenylazo-1.2-dioxan-3-ol (12).