Synthesis, characterization and spectral investigation of salen-type cobalt(iii) schiff base complexes. x-ray crystal structure of trans-[Co(Me-Salen)(3-Acetylpyridine)2]ClO4

Two new cobalt(III) complexes of the Schiff base N,N??-bis(methylsalicylidene)-1,2-ethylenediimine dianion (Me-Salen), trans-[Co(Me-Salen)(L)₂]ClO₄ (L = 3-acetylpyridine) (I) and (L = 4-acetylpyridine) (II), have been synthesized and characterized by elemental analyses, FT-IR, UV-Vis, and ¹H NMR spectroscopy. The X-ray diffraction analysis reveals that I crystallizes in the monoclinic space group P2₁/c and displays a distorted octahedral coordination geometry about Co with the equatorial plane formed by the N₂O₂ donors of the tetradentate Schiff base dianion, the two phenolate O atoms and the two imine N atoms of which are each mutually in cis-position. Two 3-acetylpyridine molecules are attached to the metal atom to fill its axial positions.     

Heterovalent trinuclear Co(III)-Co(II)-Co(III) complexes with N-(2-Carboxyethyl)salicylaldimines

The heterovalent trinuclear cobalt complexes [Co₂^IIIL₄ ⁱ · Co^II(H₂O)₄] · nXmY (L ⁱ are deprotonated Schiff bases derived from substituted salicylaldehydes and β-alanine; i = 1–3) were obtained and characterized. An X-ray diffraction study of the trinuclear cobalt complex with N-(2-carboxyethyl)salicylaldimine showed that the central Co(II) ion and the terminal Co(III) ions are linked by bridging carboxylate groups. Either terminal Co(III) atom is coordinated to two ligand molecules. They form an octahedral environment consisting of two azomethine N atoms, two phenolate O atoms, and two O atoms of two carboxylate groups. The central Co(II) atom is coordinated to four water molecules and to two O atoms of two bridging carboxylate ligands involved in the coordination sphere of the terminal Co(III) atoms.     

The copper(II) acetate complex with 2-(2-Hydroxyphenyl)-4,4-diphenyl-1,2-dihydro-4H-3,1-benzoxazine

The Cu(II) acetate complex with 2-(2-hydroxyphenyl)-4,4-diphenyl-1,2-dihydro-4H-3,1-benzoxazine (L) was synthesized for the first time and structurally studied by X-ray diffraction. The complex crystallizes as two crystallographically independent centrosymmetric binuclear molecules [Cu₂(μ-L)₂Ac₂] of similar structure, where L occurs as azomethin tautomeric form. The ligand performs tridentate chelate-bridging function. Each Cu atom exhibits extended tetragonal-pyramidal coordination by two O atoms and the N atom of one ligand L in the equatorial plane and by the O atom of the second ligand L in the axial position. The fourth equatorial position in the metal coordination polyhedron is occupied by the O atom of monodentate terminal acetate group.     

Complex [MoO2(L)(CH3OH)] (L2- = 3-methoxysalicylidenemonoethanolimine anion): Synthesis,crystal and molecular structures

The complex [MoO₂(L)(CH₃OH)] (where L^2- is 3-methoxysalicylidenemonoethanolimine anion) has been prepared and structurally characterized by X-ray diffraction. The molybdenum atom has an octahedral coordination to two ligands in cis-positions to each other, two oxygen atoms, the nitrogen atom of the tridentate bis(chelate) L^2- ligand, and also the oxygen atom of methanol. Strong O-H?O hydrogen bonds (O?O, 2.598 Å) link pairs of molecules into centrosymmetric pseudo-dimers.     

Crystal and molecular structure and electronic structure of a copper(II) complex with 10-(1-phthalazinylazo)-9-phenanthrol (HL) [Cu2(L)2(H2O)4](ClO4)2

The [Cu₂(L)₂(H₂O)₄](ClO₄)₂ compound (I) have been synthesized by the reaction of 10-(1-phthalazinylazo)-9-phenanthrol (HL) with tetraamminecopper(II) perchlorate, and its crystal and molecular structure has been determined by X-ray crystallography. The L anion acts as a tridentate chelating ligand and is coordinated to the Cu atom through the O(1) atoms of the phenanthrenequinone moiety, the N(1) atom of the phthalazinyl moiety, and the N(3) atom of the azo group to form two five-membered chelate rings. The coordination polyhedron of each Cu(1,2) atom is completed to a prolate tetragonal (4 + 1) pyramid by two water molecules with the O(2)(H₂O) atom in the axial position. The molecular and electronic structures of the HL molecule and [Cu(L)(H₂O)₂]⁺ ion have been determined by the density functional theory method. The results of quantum-chemical calculation are shown to fit well to the values found by X-ray crystallography.     

Cobalt(II) complex with pyridyl nitronyl nitroxide radical: Synthesis, crystal structure, and magnetic property of [Co(PyNIT)2(PhCOO)2(H2O)2]

A new cobalt coordination compound with nitronyl nitroxide and benzonate, Co(PyNIT)₂(PhCOO)₂(H₂O)₂, where PyNIT = 2-(p-pyridyl)-4,4??,5,5??-tetramethylimidazoline-1-oxyl-3-oxide, was synthesized and its X-ray diffraction analysis was carried out. The crystals were triclinic: a = 6.7749(4), b = 11.3472(7), c = 12.9066(8) ?, ?? = 87.906(1)°, ?? = 88.631(1)°, ?? = 79.080(1)°, V = 973.45(10) ?³, space group P $ \bar 1 $ , Z = 1, ??_calcd = 1.375 mg/m³, R = 0.0316. The environment of the cobalt atom is distorted octahedral formed by two oxygen atoms of two carboxylate groups of benzoate, two oxygen atoms of waters and two nitrogen atoms from two pyridyl nitronyl nitroxide molecules.     

Synthesis and Crystal Structure of a New Complex {[Co~(Ⅲ)L_2]·[Co~(Ⅱ)(H_2O)_6]_(0.5)·2.25H_2O}_4 (H_2L = N-(2-Hydroxyphenyl)salicylidenimine)

The reaction of Co(OAc)2·4H2O with the Schiff base H2L in a methanol solution affords the red crystals of {[CoIIIL2]·[CoII(H2O)6]0.5·2.25H2O}4 1 (H2L = N-(2-hydroxyphenyl) sali-cylidenimine). The molecular and crystal structures were determined by single-crystal X-ray diffraction. The crystal is of monoclinic, space group P21/n, C104H114Co6N8O37, Mr = 2421.61, a = 10.625(3), b = 16.335(4), c = 15.265(4) , β = 102.990(4)o, V = 2581.6(11) 3, Z = 1, Dc = 1.558 g/cm3, μ = 1.034 mm-1, F(000) = 1252, R = 0.0414 and wR = 0.1167 for 5889 reflections. The Co(III) atom is six-coordinated by two nitrogen atoms and four oxygen atoms of two tridentate L ligands. The abundant hydrogen bonding interactions extend the complex into a one-dimensional supra-molecular framework. The uncoordinated water molecules act as space-fillers and consolidate the whole architecture through the hydrogen bonding interactions.     

Molecular complexes of cobalt(II) and Zinc(II) chlorides and bromides with 1-piperidinyl dimethylcarbamodithioate (L): Crystal structures of L and [ZnLBr<Subscript>2</Subscript>]

Complexes of MX₂(M = Co, Zn; X = Cl, Br) with 1-piperidinyl dimethylcarbamodithioate (L) of composition [MLX₂] have been synthesized. The compounds have been studied by elemental analysis; X-ray diffraction; thermogravimetry; conductometry; magnetochemistry; and IR, ¹H NMR, and electronic absorption spectroscopy. The ligand molecule is coordinated to the metal atoms in a bidentate chelating mode through the thione sulfur atom and the sulfenamide nitrogen atom to form a five-membered chelate ring. The structures of L and [ZnLBr₂] have been determined by X-ray crystallography.     

Crystal structure and thermal properties of novel Co(II) complexes with 2,6-pyridine-dicarboxylate containing infinite one-dimensional chain: [CoL1(H2O)4][Co(pydc)2]·2H2O and [Co(H2O)6]×[Co(pydc)2]L2·H2O (L1 = 1,3-bis(4-pyridyl)propane, L2 = 3-amino-1H-1,2,4-triazole, pydc = 2,6-pyridine-dicarboxylic acid)

The two title compounds were prepared from the ligand pydc with cobalt(II) acetate in the presence of L¹ and L² (L¹ = 1,3-bis(4-pyridyl)propane, L² = 3-amino-1H-1,2,4-triazole, pydc = 2,6-pyridinedicarboxylic acid). The complexes were characterized by elemental analysis, IR spectrum and single crystal X-ray diffraction. Single crystal analysis shows that in two complexes coordination number around Co atom is six with distorted octahedral geometry, and both two complexes consist of ion pairs containing cationic [Co(H₂O) _n ]²⁺ and anionic [Co(pydc)₂]^2- units.     

Synthesis and structure of the mixed-ligand cobalt(III) complex [Co(DH)(Hthsc)2][SiF6] · 2.3H2O

The compound [Co(DH)(Hthsc)₂][SiF₆] · 2.3H₂O, where DH^? is a dimethylglyoxime residue and Hthsc is a thiosemicarbazide molecule, was synthesized and studied by X-ray diffraction. The coordination polyhedron of the central metal ion (distorted octahedron) is formed by two sulfur atoms, two nitrogen atoms of two Hthsc molecules coordinated in the bidentate mode, and two nitrogen atoms of the DH^? ligand. The positions of three metal rings are fixed by two intramolecular hydrogen bonds (N-H…O). A bifurcated system of intermolecular hydrogen bonds forms a framework structure in the crystal.     

Crystal structure of NaBa2[Co(Edta)]2(ClO4)3 · 9H2O

Crystals of Ba Na ethylenediaminetetraacetatocobaltate(III) perchlorate, NaBa₂[Co(Edta)]₂(ClO₄)₃ · 9H₂O, contain two crystallographically nonequivalent Ba²⁺ cations and two complex cations [Co(Edta)]^? (Edta^4? is ethylenediaminetetraacetic acid anion), the latter anions showing opposite chirality. The nearest surrounding of the Ba²⁺ ions involves three water molecules (including two bridging water molecules), six O atoms of four complexes [Co(Edta)]^? and the perchlorate O atom. Tetrameric fragments Ba₂(H₂O)₄[Co(Edta)]₂(ClO₄)₂ are united through the Ba-O bonds into layers with the Ba atoms in the middle of the layers and the perchlorate ions and complex anions at the periphery; in the latter anions, noncoordinated O atom of one of the R-metallocycles is directed outside. The Na atom of the Na(H₂O)(ClO₄) group located between the layers is bonded to these O atoms of the neighboring layers.     

Synthesis,crystal structure,and electronic structure of a copper(II) chloride complex with 9(E)-phenanthrene-9,10-dione[(1Z)-3,3-dimethyl-3,4-dihydroisoquinolin-1(2H)-ylidene]hydrazone [Cu2(L-H)2Cl2]

The [Cu₂(L-H)₂Cl₂] compound (I) has been obtained by the reaction of 9(E)-phenanthrene-9,10-dione[(1Z)-3,3-dimethyl-3,4-dihydroisoquinolin-1(2H)-ylidene]hydrazone with copper(II) chloride. The crystal and molecular structure of I has been determined by X-ray crystallography. The L-H anion acts as a tridentate chelating ligand and is coordinated to the Cu atom through the O(1) atoms of the phenanthrenequinone moiety, the N(1) atom of the dihydroisoquinoline moiety, and the N(3) atom of the azo group to form two five-membered chelate rings. Complex I is a dimer with a double chloride bridge. The coordination polyhedron of the Cu atom is completed to a distorted pyramid by two chlorine atoms. The molecular and electronic structures of the L molecule and the model [Cu(L-H)Cl] complex have been determined by the density functional theory method. Spectroscopic characteristics of I have been determined.     

Die Molekül- und Kristallstruktur von [Co3(CN)2 {(OH)4} (NH3)8][Co2(NO2)6 {(OH)2, NO2}] · H2O

The structure of [Co₃(CN)₂ {(OH)₄} (NH₃)₈] [Co₂(NO₂)₆ {(OH)₂, NO₂}] · H₂O has been determined by X-ray methods. The compound crystallizes in the monoclinic space group C_2h⁵–P2₁/n with a = 7.21, b = 12.38, c = 33.13 Å, β = 94°, Z = 4. The crystals contain trinuclear cations in which three Co(III) atoms are bound to two pairs of oxygen atoms. At the central Co atom there are two CN^– ligands in the cis position. The cation is of symmetry C₂. The anion is found to be a binuclear Co(III) complex. The two Co atoms are bound to two OH^– and one NO₂^– groups.     

Crystal structure of barium (cyclohexane-1,2-diaminetetraacetato)cobaltate(III) nonahydrate Ba[Co(Cdta)]2 · 9H2O

The crystal structure of Ba[Co(Cdta)]₂ · 9H₂O has been determined by X-ray diffraction. The crystals are monoclinic, a = 15.9415(10) Å, b = 7.8449(6) Å, c = 32.230(2) Å, β = 100.387(8)°, Z = 4, space group C2/c)). The cyclohexane-1,2-diaminetetraacetate ion forms the octahedral [Co(Cdta)]^? complex through two donor nitrogen atoms and four oxygen atoms and is also connected to two barium atoms through oxygens. The Ba atoms are on a twofold axis. Its nearest environment comprises five O atoms of water molecules, one also being located on a twofold axis, and four O atoms of the four neighboring complex ions. This gives infinite layers parallel to the ab plane. All water molecules form hydrogen bonds within one layer.     

Cymantrenecarboxylate complexes of nickel(II) and cobalt(II)

Reactions of cymantrenecarboxylic acid (CO)₃MnC₅H₄COOH (CymCOOH) with Ni(II) and Co(II) pivalates in boiling THF followed by extraction of the products with diethyl ether or benzene and treatment with triphenylphosphine gave the binuclear complexes LM(CymCOO)₄ML (M = Ni (I) and Co (II); L = PPh₃). Treatment of the benzene extract of the intermediate cobalt cymantrenecarboxylate with 2,6-lutidine (L’) yielded the trinuclear complex L’Co(CymCOO)₃Co(CymCOO)₃CoL’ (III). Complex I is antiferromagnetic; μ_eff decreases from 3.7 to 0.9 μ_B in a temperature range from 300 to 2 K. Structures I-III were identified using X-ray diffraction. The frameworks of complexes I and II are like Chinese lanterns, having four carboxylate bridges and axial ligands L (Ni-P, 2.358(1) Å; Co-P, 2.412(2) Å). The metal atoms are not bonded to each other (Ni…Ni, 2.7583(9) Å; Co…Co, 2808 (2) Å). In complex III, either terminal Co atom is coordinated to one ligand L’ (Co-N, 2.059(2) Å). The Co atoms form a linear chain showing no M-M bonds (Co…Co, 3.346(1) Å), in which either terminal Co atom is linked with the central Co atom by three carboxylate bridges (on average, Co_centr-O, 2.164 Å; CO_term-O, 2.094 Å). In one of three carboxylate groups, only one carboxylate O atom serves as a bridge, while the other is bonded to the terminal Co atom only (Co_term-O, 2.094 and 2.389 Å); so this carboxylate group is a bridging and chelating ligand.     

Construction of a Novel 2D Polymer [Co（dmpzm）（dca）2]∞ from Reaction of a Mononuclear Complex [Co（dmpzm）Cl2] with Sodium Dicyanamide （dca） [dmpzm=bis（3,5-dimethylpyrazolyl）methane]

Reaction of COC12.6H20 with equimolar bis（3,5-dimethylpyrazolyl）methane （dmpzm） produced a mononuclear adduct [Co（dmpzm）Cl2] （1）. Treatment of 1 with sodium dicyanamide （dca） afforded a polymeric complex [Co（dmpzm）（μ-dca）2]∞ （2）. 1 and 2 were characterized by elemental analysis, IR spectra, thermogravimetric analysis and single-crystal X-ray diffraction. The cobalt atom in 1 adopts a distorted tetrahedral coordination geometry, bound to two N atoms of one dmpzm and two Cl atoms. Complex 2 has a 2D brick-wall network （extended along the bc plane） in which the { [Co（dmpzm）（μ-dca）]2} n^2n＋ chains are interconnected by pairs of μ-dca anions along the c axis. The magnetic properties of 1 and 2 were also investigated.     

{[Cd(NTO)2(CHZ)]·2H2O}n的合成、分子结构和热分解机理

通过3-硝基-1,2,4-三唑-5-酮(NTO)镉与碳酰肼(NH₂NHCONHNH₂,CHZ)反应制备出了新型配合物{[Cd(NTO)₂(CHZ)]·2H₂O}_n,研究了其分子结构和热分解机理。该配合物的晶体属正交晶系,Pbca空间群,晶体学参数:a=0.8623(1)nm,b=1.8259(4)nm,c=1.9997(3)nm     

SYNTHESIS AND CHARACTERIZATION OF DIAQUA(3-pTOLYLIMINO-2-BUTANONE OXIMATO)(3-p-TOLYLIMINO-2-BUTANONE OXIME)NICKEL(II) PERCHLORATE

Abstract

[Ni(L^?1)(HL)(H₂O)₂].ClO₄ with a Schiff base ligand L (HL = 3-p-tolylimino-2-butanone oxime) was prepared and structurally characterized by IR, cyclic voltammetry and X-ray diffraction methods. The nickel atom has distorted octahedral coordination consisting of four nitrogen atoms and two oxygen atoms. The equatorial plane is formed by two oxime nitrogen atoms and two imine nitrogen atoms of two Schiff base ligand (L^?1 and HL) with Ni‐ N bond distances between 2.01(1) and 2.11(1)Å. Water oxygen atoms occupy axial positions with Ni‐ O bond distances of 2.06(1) and 2.15(1) Å. The oxime groups in the Schiff base ligands are coordinated to Ni atom through their nitrogen atoms. One asymmetric intramolecular hydrogen bridge between the two oxime groups is found in the title complex.     

Crystal Structure of Praseodymium(III) Complex [Pr(DMSO)8]2PMo10V2O40(NO3) · DMSO (DMSO = Dimethyl Sulfoxide)

Crystal structure of [Pr(DMSO)₈]₂PMo₁₀V₂O₄₀(NO₃) · DMSO (where DMSO is dimethyl sulfoxide) is determined by X-ray diffraction analysis. The Pr atom forms coordination polyhedron shaped like a distorted square antiprism with Pr–O distances varying from 2.432(6) to 2.476(6) Å. The oxygen atoms of a heteropolyanion are not involved in the coordination sphere of the Pr atom.     

Syntheses,Crystal Structures,and Antibacterial Activities of Four Schiff Base Copper(II), Zinc(II), and Cadmium(II) Complexes Derived from 2‐[(2‐Dimethylaminoethylimino)methyl]phenol

Four Schiff base complexes, [Zn₂L₂(NCS)₂] ( 1 ), [Cd₂L₂(NCS)₂]_n ( 2 ), [Zn₄L₂(N₃)₂Cl₄(OH₂)(CH₃OH)] ( 3 ), and [Cu₄L₂(N₃)₂Cl₄(OH₂)(CH₃OH)] ( 4 ) (where L = 2‐[(2‐dimethylaminoethylimino)methyl]phenol), were synthesized and characterized by elemental analyses, infrared spectroscopy, and single crystal X‐ray determinations. Both 1 and 2 are structurally similar polynuclear complexes. In 1 , each Zn atom has a slightly distorted square‐pyramidal coordination configuration. In the basal plane, the Zn atom is coordinated by one O and two N atoms of one L, and by one O atom of another L. The apical position is occupied by one terminal N atom of a coordinated thiocyanate anion. The Zn···Zn separation is 3.179(3) Å. While in 2 , the Cd1 atom is six‐coordinated in an octahedral coordination. In the equatorial plane, the Cd1 atom is coordinated by one O and two N atoms of one L, and by one O atom of another L. The axial positions are occupied by the terminal N and S atoms from two bridging thiocyanate anions. The coordination of Cd2 atom in 2 is similar to those of the zinc atoms in 1 . The Cd···Cd separation is 3.425(2) Å. Both 3 and 4 are novel tetra‐nuclear complexes. Each metal atom in the complexes has a slightly distorted square‐pyramidal coordination. The arrangements of the terminal metal atoms are similar, involving one O and two N atoms of one L ligand and one bridging Cl atom defining the basal plane, and one O atom of a coordinated water molecule or MeOH molecule occupying the apical position. The coordinations of the central metal atoms are also similar. The basal plane of each metal atom involves one O atom of one L ligand, one terminal Cl atom, and two terminal N atoms from two bridging azide groups. The apical position is occupied by a bridging Cl atom which also acts as a basal donor atom of the terminal metal atom. The Schiff base ligand and the four complexes showed high selectivity and antibacterial activities against most of the bacteria.