Synthesis and spectroscopic studies of transition metal dinuclear/ polynuclear complexes with azolo-2,4-pentanedione

Summary Biologically relevant azolo (triazolo and thiazolo) diazonium salts were coupled with 2,4-pentanedione. The resulting substituted 2,4-pentanedione (L₁ and L₂) were condensed with 1,6-diaminohexane in the presence of chloride salts of nickel(II), copper(II), platinum(II), platinum(IV) and palladium(II) or nickel(II) and copper(II) acetates. The resulting dinuclear/polynuclear complexes were characterized by elemental analyses, conductance and magnetic moments, as well as i.r., u.v.-vis., ¹H n.m.r. and e.s.r. spectra.     

Physicochemical and Biological Characterization of Transition Metal Complexes with a Nitrogen Donor Tetra-dentate Novel Macrocyclic Ligand

A novel tetradentate nitrogen donor [N₄] macrocyclic ligand, i.e. 3,5,13,15,21,22-hexaaza-2,6,12,16-tetramethyl-4,14-dithia-tricyclo[15.3.1.1(7–11)]docosane-1(21),2,5,7,9,11(22),12,15,17,19-decaene, has been synthesized. Mn(II), Co(II), Ni(II) and Cu(II) complexes with this ligand have been prepared and subjected to elemental analyses, molar conductance measurements, magnetic susceptibility measurements, mass, ¹H-n.m.r. (Ligand), i.r., electronic, and e.p.r. spectral studies. On the basis of molar conductance the complexes may be formulated as [M(L)X₂] and [Ni(L)]X₂ [where M = Mn(II), Co(II) and Cu(II), and X = Cl⁻ and NO₃⁻] due to their nonelectrolytic nature in dimethylsulphoxide (DMSO). All the complexes are of the high spin type and are six coordinated. On the basis of i.r., electronic and e.p.r. spectral studies an octahedral geometry has been assigned to Mn(II) and Co(II), square planar for Ni(II) complexes, and tetragonal for Cu(II) complexes. The antimicrobial activities of the ligand and its complexes, as growth inhibiting agents, have been screened in vitro against several species of bacteria and plant pathogenic fungi.     

Preparation,infrared, Raman and N.M.R. spectra of N,N′-Diethylthiourea complexes with zinc(II), cadmium(II) and mercury(II) halides

Several complexes of N,N′-diethylthiourea (Dietu) with zinc(II), cadmium(II) and mercury(II) halides were prepared and characterized by i.r. (4000–60 cm^?1), raman (400–60 cm^?1), in the solid state and n.m.r. and conductometric methods in solution. The complexes Zn(Dietu)₂X₂, Cd(Dietu)₂X₂ (X ? Cl, Br, I) and Hg(Dietu)₂X₂ (X ? Br, I) are tetrahedral species in which intramolecular ? NH …? X interactions have been observed. The 1:1 mercury(II) complexes, Hg(Dietu)X₂ (X ? Cl, Br), appear to have a dimeric tetrahedral halide-bridged structure in the solid state. In all these complexes N,N′-diethylthiourea is sulphur-bonded to the metal.     

Synthesis and structural studies of (2 E ,3 E ,6 R ,9 E ,11 E )-6-isopropenyl-3,6,10-trimethyl-5,8-dioxa-4,9-diazadodeca-3,9-diene-2,11-dione dioxime, ligand and its Mono-, homo, and heterodinuclear copper(II)/nickel(II) complexes

This article describes the synthesis of a new (2E,3E,6R,9E,11E)-6-isopropenyl-3,6,10-trimethyl-5,8-dioxa-4,9-diazadodeca-3,9-diene-2,11-dione dioxime (H₂hmdm), and its mono-, homo, and heterodinuclear copper(II)/nickel(II) complexes. Elemental analyses, stoichiometric and spectroscopic data of the metal complexes indicated that the metal ions are coordinated to the oxime and imine nitrogen atoms (C=N). The Cu(H₂hmdm), molecule coordinates to the second copper(II) ion through the oximate oxygens to afford a binuclear structure doubly bridged by the oximate groups in the cis arrangement. In the dinuclear complexes, in which the first Cu^II ion was complexed with nitrogen atoms of the oxime and imine groups, the second Cu^II ion is ligated with the 1,10-phenanthroline nitrogen atoms. Ligand and its mononuclear copper(II), homo and heterodinuclear copper(II)–nickel(II) complexes of (H₂hmdm) were characterized by elemental analyses, magnetic moments, ¹H-n.m.r. and ¹³C-n.m.r., i.r., and mass spectral studies. The data support the proposed structure of H₂hmdm and its complexes.     

Metall-Pseudohalogenide. XL. Zur Kenntnis anionischer Dicyanamidkomplexe [M{N(CN)2}4]2− des Palladium(II) und Platin(II)

Metal Pseudohalides. XL. Dicyanamido Metallates [M{N(CN)₂}₄]^2? of Palladium(II) and Platinum(II) The synthesis of homologeous tetrakis-(dicyanamido) metallates(II), [M{N(CN)₂}₄]^2? is reported. The coordination type of the ambivalent dicyanamide ligand is discussed on the basis of the i.r. and n.m.r. spectra of the new complexes.     

Spectral,physicochemical and biological characterization of 2,5,11,14,19,20-hexaaza-3,12-dimethyl-4,13-dipropyl-tricyclo [13.3.1.1(6-10)]cosane-1(19),2,4,6(20),7,9,11,13,15,17-decaene and its transition metal complexes

The synthesis of a tetradentate nitrogen donor macrocyclic ligand i.e. 2,5,11,14,19,20-hexaaza-3,12-dimethyl-4,13-dipropyl-tricyclo[13.3.1.1(6-10)]cosane-1(19),2,4,6(20),7,9,11,13,15,17-decaene and its complexes with manganese(II), cobalt(II), nickel(II) and copper(II) have been reported. The complexes were characterized by elemental analyses, molar conductance measurements, magnetic susceptibility measurements, mass, ¹H-n.m.r. (Ligand), i.r., electronic, and e.p.r. spectral studies. On the basis of molar conductance the complexes may be formulated as [M(L)X₂] [where M = Mn(II), Co(II), Ni(II) and Cu(II), and X = Cl⁻ & NO ₃⁻ ] due to their nonelectrolytic nature in dimethylformamide (DMF). All the complexes are of the high spin type and are six coordinated. On the basis of i.r., electronic and e.p.r. spectral studies an octahedral geometry has been deduced for Mn(II), Co(II) and Ni(II) complexes, and tetragonal geometry for Cu(II) complexes. The antimicrobial activities of the ligand and its complexes, as growth inhibiting agents, have been screened in vitro against several species of bacteria and plant pathogenic fungi.     

Spectral and biological investigation of 5-hydroxyl-3-oxopyrazoline 1-carbothiohydrazide and its transition metal complexes

Mononuclear complexes of 5-hydroxyl-3-oxopyrazoline-1-carbothiohydrazide, H₃HOC, with VO²⁺, Co(II), Ni(II), Cu(II) and Cd(II) have been isolated. The elemental analyses, magnetic, spectral [u.v.–vis., i.r., e.s.r. ¹H n.m.r. and mass] with thermal analysis have been used to characterize the isolated complexes. The ligand behaves as a mononegative tridentate with Ni(II) and Co(II) ions and neutral bidentate in [Cu(H₃HOC)(NO₃)₂]0.5 H₂O, [VO(H₃HOC)SO₄] and [Cd(H₃HOC)Cl₂C₂H₅OH]C₂H₅OH complexes. The octahedral structure was suggested for all the isolated complexes except VO²⁺. The TG analyses recorded different decomposition steps started at a temperature, indicating thermally unstable complexes. Screening showed antimicrobial activity for Cd(II) and Ni(II) complexes against the investigated bacteria as well as a significant adverse effects on DNA but a moderate effect is displayed with the other complexes.     

Modern spectroscopic and biological approach in the characterization of a novel 14-membered [N<Subscript>4</Subscript>] macrocyclic ligand and its transition metal complexes

A novel tetradentate nitrogen donor [N₄] macrocyclic ligand, i.e. 1,3,4,8,9,11-hexaaza-2,5,10,12-tetraoxo-7,14-diphenyl-cyclotetradecane (L), has been synthesized. Mn(II), Co(II), Ni(II) and Cu(II) complexes of this ligand have been prepared and subjected to elemental analyses, molar conductance measurements, magnetic susceptibility measurements, mass, ¹H-n.m.r. (Ligand), i.r., electronic, and e.p.r. spectral studies. On the basis of molar conductance the Mn(II), Co(II) and Cu(II) complexes may be formulated as [M(L)X₂] [where X = Cl⁻ & NO ₃ ⁻ ] due to their non-electrolytic nature in dimethylformamide (DMF). Whereas the Ni(II) complexes are 1:2 electrolytes and formulated as [Ni(L)]X₂. All the complexes are of the high spin type and are six/four coordinate. On the basis of i.r., electronic and e.p.r. spectral studies an octahedral geometry has been assigned to Mn(II) and Co(II), square planar for Ni(II) complexes, and tetragonal for Cu(II) complexes. The antimicrobial activities of the ligand and its complexes, as growth inhibiting agents, have been screened in vitro against several species of bacteria and plant pathogenic fungi.     

Untersuchungen und Strukturanalyse von Eisen(II)-, Cobalt(II)- und Nickel(II)-Komplexen nach synergistischer Extraktion

Zusammenfassung Die synergistische Extraktion von Eisen(II)-, Cobalt(II)- und Nickel(II)-Komplexen wird untersucht. Verwendet wurden fluorierte Diketone (A) (Hexafluoroacetylaceton und Derivate des Thenoyltrifluoracetons) und Abkömmlinge des Pyridinal(2)-phenylimins und des Bis-(pyridinal-2-)-diimines (B). Aus den Extraktionskurven nach der Job- und der Molar-Ratio-Methode, der Elementaranalyse und aus Molmassenbestimmungen werden Komplexverbindungen der Zusammensetzung [MA₂B¹], [M₂A₄B²] und [M₃A₆B³] nachgewiesen. Aus den Elektronen- und IR-Spektren und aus magnetischen Messungen wird für die Ni(II)-Komplexe eine octaedrische Struktur vorgeschlagen.

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Investigation and structure analysis of iron(II), cobalt(II) and nickel(II) complexes after synergistic extraction

Summary The synergistic extraction of iron(II), cobalt(II) and nickel(II) complexes was investigated. Fluorinated diketones (A) (hexafluoroacetylacetone and derivatives of thenoyltrifluoracetones) and derivatives of pyridinale(2)-phenylimine and bis(pyridinale-2-)diimine (B) were used. By Job and molar-ratio investigation on the extraction curves, by elementary analysis and molar mass detection complex compounds of the composition [MA₂B¹], [M₂A₄B²] and [M₃A₆B³] could be proved. Electron and infrared spectra and magnetical measurements led to an octahedral structure proposal for the Ni(II)-complexes.

Wir danken Herrn Dr. Bodo Plewinsky, Institut für Anorganische Chemie der FU Berlin, sehr herzlich für die Bestimmung der Molmassen mit der Ultrazentrifuge.     

The i.r. spectra of ethylenediamine complexes—I. The tris(ethylenediamine) complexes of first transition series metal(II) sulphates

The i.r. spectra of the complex [Zn(en)₃]SO₄ and its ⁶⁴Zn-, ⁶⁸Zn-, ¹⁵N-, N₂D₄- and C₂D₄-labelled analogues have been determined over the range 4000-50 cm⁻¹. Band assignments are based on the isotopically induced shifts and also those which result from substitution of Zn(II) by the metal(II) ions of the first transition series: Mn(II), Fe(II), Co(II), Ni(II) and Cu(II). The spectrum of the Cu(II) complex yields evidence of Jahn—Teller distortion.     

Structure and complexation equilibria of metal(II) ions with 4-arylazopyrazoles

Summary Octahedral mononuclear and tetrahedral binuclear 4-arylazo-3,5-diaminopyrazole complexes of copper(II), nickel(II), cobalt(II) and manganese(II) have been prepared and characterized by elemental analysis, conductivity measurements and by i.r., ¹H n.m.r. and electronic spectroscopy. Complexation equilibria, stoichiometry and stability constants were measured in 40% (v/v) EtOH-H₂O medium and I = 0.1 mol dm ⁻³ NaClO₄. In mild acidic media, the ligands behave as neutral NN′ bidentates, while in alkaline media they act as N²N₂′ tetradentate ligands.     

Osmium(II)-Phthalocyanine: Darstellung und Eigenschaften von Di(acido)phthalocyaninatoosmaten(II)

Osmium(II) Phthalocyanines: Preparation and Properties of Di(acido)phthalocyaninatoosmates(II) “H[Os(X)₂Pc^2?]” (X = Br, Cl) reacts in basic medium or in the melt with (ⁿBu₄N)X forming less stable, diamagnetic, darkgreen (ⁿBu₄N)₂[Os(X)₂Pc^2?]. Similar dicyano and diimidazolido(Im) complexes are formed by the reaction of “H[Os(Cl)₂Pc^2?]” with excess ligand in the presence of [BH₄]^?. The cyclic voltammograms show up to three quasireversible redoxprocesses: E_1/2(I) = 0.13 V (X = CN), ?0.03 V (Im), ?0.13 V (Br) resp. ?0.18 V (Cl) is metal directed (Os^II/III), E_1/2(II) = 0.69 V (Cl), 0.71 V (Br), 0.83 V (CN), 1.02 V (Im) is ligand directed (Pc^2?/?) and E_1/2(III) = 1.17 V (Cl) resp. 1.23 V (Br) is again metal directed (Os^III/IV). Between the typical “B” (～16.2 kK) and “Q” (～29.4 kK), “N regions” (～34.1 kK) up to seven strong “extra bands” of the phthalocyanine dianion (Pc^2?) are observed in the uv-vis spectrum. Within the row CN > Im > Br > Cl, most of the bands are shifted slightly, the “extra bands” considerably more to lower energy in correlation with E_1/2(I). The vibrational spectra are typical for the Pc^2? ligand with D_4h symmetry. M.i.r. bands at 514, 909, 1 173 and 1 331 cm^?1 are specific for hexa-coordinated low spin Os^II phthalocyanines. In the resonance Raman (r.r.) spectra polarized, depolarized or anomalously polarized deformation and stretching vibrations of the Pc^2? ligand will be selectively enhanced, if the excitation frequency coincides with “extra bands”. With excitation at ～19.5 kK the intensity of the symmetrical Os? X stretching vibration at 295 cm^?1 (X = Cl), 252 cm^?1 (X = Im) and 181 cm^?1 (X = Br) is r.r. enhanced, too. The asymmetrical Os? X stretching vibration is observed in the f.i.r. spectrum at 345 cm^?1 (X = CN), 274 cm^?1 (X = Cl), 261 cm^?1 (X = Im) and 200 cm^?1 (X = Br).     

Synthesis and spectral characterization of 1-phenylglyoxal bis{N(4)ethylthiosemicarbazone} and its metal complexes

Nickel(II), copper(II), zinc(II), and cadmium(II) complexes of 1-phenylglyoxal bis{N(4)-ethylthiosemicarbazone} have been synthesized and characterized spectroscopically. The bis(thiosemicarbazone) and its diamagnetic complexes have been characterized by their melting points, i.r., electronic, mass and ¹H n.m.r. spectra. The four-coordinate copper(II) complex was also studied by e.s.r. spectroscopy. Upon coordination, the loss of a proton from each thiosemicarbazone moiety occurs, and the bis(thiosemicarbazone) coordinates to nickel(II) and copper(II) as a dianionic, tetradentate N₂S₂ ligand; but for zinc(II) and cadmium(II), mass spectral results suggest the formation of binuclear complexes.     

Synthesis and spectroscopic studies of new binuclear transition metal complexes of Schiff bases derived from 4,6-diacetylresorcinol

Two new series of copper(II), nickel(II), cobalt(II), zinc(II), iron(III), chromium(III), vanadyl(IV) and uranyl(VI) complexes with two bifunctional tridentate Schiff base, H₄L¹ and H₂L² ligands have been prepared. The Schiff base, H₄L¹ and H₂L², ligands were synthesized by the condensation of 4,6-diacetylresorcinol with o-aminophenol or o-phenylenediamine. The ligands are either di- or tetra-basic with two symmetrical sets of either OON or NNO tridentate chelating sites. The ligands and their metal complexes have been characterized by elemental analysis, ¹H-n.m.r., FT-IR, mass, electronic, esr spectra and thermal gravimetric analysis and magnetic susceptibility. With the exception of Co^II ion with H₂L² which afforded a trinuclear complex, a variety of binuclear complexes for the rest of the metal complexes were obtained with the ligands in its di- or tetra-deprotonated forms. The bonding sites are the azomethine and amino nitrogen atoms, and phenolic oxygen atoms. The metal complexes exhibit different geometrical arrangements such as square planar, tetrahedral, square pyramid and octahedral arrangement.     

Mononuclear and binuclear manganese(II) complexes with tridentate bis-benzimidazolyl ligands

Summary Manganese(II) complexes of bis(2-benzimidazolylmethyl) ether (DGB), bis(2-benzimidazolylmethyl) sulphide (TGB) and the n-butyl derivative of DGB (BDGB) were prepared and characterised. The solution e.p.r. spectrum of [Mn(TGB)Cl₂] in DMF at 143 K is commensurate with an axially distorted monomeric manganese(II) complex, room temperature magnetic moment (6.04 B.M.) per manganese(II) atom being in the range found for other d⁵ monomeric manganese(II) complexes. The solution e.p.r. spectrum of [Mn(BDGB)Cl₂]-2H₂O in DMF at 143 K indicates the presence of two equivalent manganese(II) ions coupled by an exchange interaction, fostered by bridging chlorides. Evidence for this is provided by a nearly isotropic 11 line hyperfine structure of ⁵⁵Mn, with a coupling constant 45 ± 5G. Contact-shifted ¹H n.m.r. data also supports an exchange coupled dimeric manganese complex. The room temperature magnetic moment, 5.64 B.M., per manganese(II) indicates quenching of the magnetic moment below that of monomeric manganese(II) ion. The [Mn(DGB)Cl₂]·H₂O complex exhibits a magnetic moment of 6.02 B.M. per manganese, indicating a monomeric manganese complex. E.p.r. data of the complex diluted in an analogous Zn-DGB complex (1∶20) correlates well for D = 0.22cm⁻¹ and λ ∼- 0.267. The [Mn(DGB)-(C1O₄)₂] and [Mn(BDGB)(ClO₄)₂] complexes, diluted in analogous Zn-DGB and Zn-BDGB complexes (1∶20), show a strong single e.p.r. line at g _eff ∼- 2. The complexes have low magnetic moments; 4.44 B.M./Mn and 4.39 B.M./Mn, at room temperature.     

Complexes of divalent transition metal chlorides with the tetradentate Schiff base ligand 1,2-bis(2′-pyridylmethyleneimino)-benzene

Summary Transition metal(II) chloro complexes of the new Schiff base ligand 1,2-bis(2-pyridylmethyleneimino)benzene (L), derived from 2-pyridinecarboxaldehyde and 1,2-phenylenediamine, were prepared. Compounds of [MnLCl₂]-H₂O, [CoLCl₂]·2H₂O, [NiLCl₂] and [Zn₃L₂Cl₄]Cl₂ were prepared. Details are given of the formation of the complex [Cu(L·EtOH)Cl₂], in which one molecule of EtOH adds across only one of the Schiff base {ie531-01} groups to give the coordinated ligand L·EtOH. The rationalization of this type of reaction by considering the steric requirements of the ligand is given. The complexes were characterized by elemental analyses, conductivity measurements, thermal techniques, mass spectra, magnetic susceptibilities and spectroscopic (i.r., ligand field, e.s.r., ¹H n.m.r.) studies. The nitrogen donor atoms of the tetradentate ligands L and L·EtOH are assumed to adopt an essentially planar arrangement about manganese(II), cobalt(II), nickel(II) and copper(II), with the remaining axial coordination sites occupied by chloro ligands to yield high-spin octahedral molecules. A trinuclear structure, based on tetrahedrally coordinated metal ions, is proposed for the zinc(II) complex.     

4-Cyanoaniline complexes with transition metal(II) halides

Summary Coordination compounds formed by the interaction of manganese(II), cobalt(II), nickel(II) and copper(II) chloride and bromide with 4-cyanoaniline (4-CA) have been prepared and characterized by molar conductance, magnetic susceptibilities, electronic and i.r. spectral measurements down to 200 cm^–1 in the solid state. The isolated complexes are M(4-CA)₂X₂ except for nickel(II) bromide which is NI(4-CA)₄Br₂. I.r. spectra, indicate that 4-CA, though a potentially bidentate ligand, nevertheless acts only as a terminally aniline (NH₂) bonded monodentate ligand in all the complexes. Tentative stereochemistries of the complexes have been suggested in the solid state.     

Synthesis and spectroscopic characterization of transition metal complexes of a 12-membered tetraaza [N<Subscript>4</Subscript>] macrocyclic ligand and their biological activity

Cobalt(II), nickel(II) and copper(II) complexes are synthesized with 1,3,7,9-tetraaza- 4,6,10,12-tetraphenyl-2,8-dithiacyclododecane, a tetradentate ligand (L) and characterized by elemental analysis, molar conductance measurements, magnetic susceptibitity measurements, mass, i.r., electronic and e.p.r. spectral studies. All the complexes are non-electrolytes so they may be formulated as [M(L)X₂] [where, M = Co(II), Ni(II) and Cu(II) and X = Cl⁻ and NO ₃ ⁻ ]. All the complexes are of high spin type. On the basis of i.r., electronic and e.p.r. spectral studies an octahedral geometry has been assigned for Co(II) and Ni(II) complexes and tetragonal geometry for Cu(II) complexes. The antimicrobial activities of the ligand and its complexes, as growth inhibiting agents, have been screened in vitro against two different species of bacteria and plant pathogenic fungi.     

Vier- und achtgliedrige metallhaltige Bor–Stickstoff-Heterocyclen. Bildung und Strukturen in Abhängigkeit von der Raumerfüllung der Substituenten

Four and Eight Membered Metal Containing Boron–Nitrogen-Heterocycles. Formation and Structures in Dependence on the Steric Requirement of their Substituents TripB(NRLi)₂ (Trip = 2,4,6-triisopropylphenyl, R = Me ( II a ), CH₂Me ( II b ), CHMe₂ ( II c ), CMe₃ ( II d ) reacts with dibromo(dimethyl)tin to give eight membered ( III a , III b ) and four membered metallacycles ( IV c and IV d ). If tetrahalides (GeCl₄, SnCl₄) are the reaction partners, the spiro compounds V c and VI d are obtained from II c and II d resp. The compounds are characterized by their m.s. and n.m.r. (¹H, ¹¹B, ¹³C, ¹⁹F, ¹¹⁹Sn) spectra and by elemental analyses. An X-ray structure analysis was performed for III a .     

The vibrational spectra of complexes with planar monothio-oxamides—I. The Ni(II), Pd(II), Pt(II), Cu(II) and Zn(II) complexes of N,N′-dimethylmonothio-oxamide

The new complexes M(LH)₂ (M = Pd,Pt), ML(M = Pd,Cu) and ML · H₂O (M = Ni,Zn), where LH₂ = N,N′-dimethylmonothio-oxamide, have been prepared. The complexes were characterized by metal analyses, thermal methods and spectral (i.r., Raman, u.v.—vis.) studies. The vibrational analyses of the complexes are given using NH/ND, CH₃/CD₃ and metal isotopic substitutions. The Ni(II), Pd(II), Pt(II) and Cu(II) compounds are square planar. The monoanion LH⁻ shows a chelated bidentate S,O-coordination, while the doubly deprotonated L²⁻ acts as a bridging S,N/N,O-tetradentate ligand giving polymeric structures.