Metal complexes of sulfur-nitrogen chelating agents. Part 12. The chemistry of nickel(II), palladium(II), cobalt(II) and copper(II) complexes of N2S2 and N3S2 donor systems

Summary Nickel(II), palladium(II), cobalt(II) and copper(II) complexes of the ligandN,N-1,2-propane-bis(methyl 2-amino-cyclopent-1-ene-dithiocarboxylate) (H₂L¹),N,N-1,3-propane-bis(methyl 2-aminocyclopent-1-ene-dithiocarboxylate) (H₂L²) andN,N-[bis(methyl 2-aminocyclopent-1-ene-dithiocarboxylate)] diethylenetriamine (H₂L³) have been synthesised. Both H₂L¹ and H₂L² form complexes of the type ML, and all but the copper(II) complexes, are square planar. In the copper(II) complexes tetrahedral distortion is significantly more with CuL². From H₂L³ square planar complexes of the type [M(HL³)X] (M=Ni, X=Cl, Br, I or SCN; M=Pd, X=Cl or Br) have been obtained in which the donor unit involved is N₂SX. The composition of the cobalt(II) and copper(II) complexes is [M(H₂L³)X₂] (X=Cl or Br) which contain the chromophore [MN₃X₂].     

Composition and stability of copper(II), nickel(II), and cobalt(II) complexes with mono- and bis(2-carboxy)-2-pycolylamine

Complexation of N-(2-pyridyl)methyl-3-aminopropionic (HL¹) and N-(2-pyridyl)methyliminodipropionic (H₂L²) acids with copper(II), nickel(II), and cobalt(II) ions is studied. The composition of complexes is determined using the Starik–Barbanel relative yield method. The acid dissociation constants of HL¹ and H₂L² are determined potentiometrically; the stability constants of HL¹ and H₂L² complexes with metal ions are calculated.     

Synthesis and characterization of 2,3-bis(hydroxyimino)-1,2,3,4-tetrahydro-pyrido[2,3-b]pyrazine and its nickel(II), cobalt(II), copper(II), palladium(II), cadmium(II) and cobalt(III) complexes

Summary 2,3-Bis(hydroxyimino)-1,2,3,4-tetrahydro-pyrido[2,3-b]pyrazine (H₂L), prepared from 2,3-diaminopyridine and cyanogen-di-N-oxide has been converted into nickel(II), palladium(II), copper(II), cobalt(II), and cobalt(III) complexes (H₂L) with a 12 metal:ligand ratio. The ligands coordinate through the two N atoms, as do most vicinal dioximes. [(LH)Cl(H₂O)Cd], contains a six-membered chelate ring. [Co(HL)₂(L)Cl] has also been prepared using triphenylphosphine, triphenylarsine, thiophene and chloride as axial ligands. The structure of thevic-dioxime and its complexes are proposed on the basis of elemental analysis, i.r.,¹H-n.m.r. and uv-visible measurements.     

Synthesis and X-ray structural characterization of cobalt(II), copper(II), and silver(I) complexes of triphenylphosphoniopropionate

Four transition-metal carboxylate-like complexes have been synthesized from the reaction of the tertiary phosphine betaine triphenylphosphoniopropionate, Ph₃P⁺(CH₂)₂CO ₂ ^– , with Co(ClO₄)₂· 6H₂O, Cu(ClO₄)₂·6H₂O, Cu(BF₄)₂·xH₂O, and AgClO₄, respectively, and fully characterized by single-crystal X-ray analysis. [CoPh₃P(CH₂)₂CO_{2 4}(H₂O)₂](ClO₄)₂·2H₂O, 1, space groupP¯ l witha=9.195(2),b=13.000(2),c=18.795(3) Å,=102.52(1),=90.12(1),=109.28(2)° andZ=1; [CuPh₃P(CH₂)₂CO_{2 4}][Cu₂ -Ph₃P(CH₂)₂CO₂ -O,O ₄(H₂O)₂] (ClO₄)₆· 4H₂O, 2, space groupP2_l/c witha=14.225(3),b=24.624(6),c=24.297(5) Å,=94.18(1)°, andZ=2; [CuPh₃,P(CH₂)₂CO₂Me₂N(CH₂)₂NMe₂(H₂O)₂](BF₄)₂,3, space groupP2_l/c witha=17.668(2),b=13.454(3),c=15.876(2) Å,=116.45(1)°, andZ=4; [Ag₂Ph₃P(CH₂)₂CO_{2 2}(ClO₄)]₂(ClO₄)₂,4, space groupP¯ l witha=10.925(2),b=13.110(3),c=18.795(3) Å,=82.93(3),=87.45(3),=67.49(3)°, andZ=2. In complex1, the cobalt(II) atom is located in an inversion center and coordinated by four unidentate betaine ligands and a pair oftrans aqua ligands, and strong hydrogen bonds are formed between the aqua ligands and the pendant oxygen atoms of the betaine ligands. In complex2, mononuclear and dinuclear cations coexist in the asymmetric unit. In the mixed-ligand complex3 the betaine ligand acts in the unidentate coordination mode andN,N,N,N-tetramethylethylenediamine (tmen) in the chelate mode. Complex4 contains a discrete centrosymmetric tetranuclear cations in which one pair of betaine ligands act in the bidentate bridging mode and the other in both bidentate and one-atom bridging modes.     

Mixed-ligand cobalt(III) complexes derived from bis(dehydroacetato)ethylenediimine

Summary A hydroxocobalt(III) complex (1a), has been obtained by reaction of bis(dehydroacetato)ethylenediimine (H₂dhaen) with cobalt(II) hydroxide or acetate in the presence of air. Addition of a second complexing agent leads to the formation of a series of mixed-ligand complexes (2)-(26) having either the trans- or cis- configuration. In the cis- complexes, the quadridentate ligand dhaen adopts a nonplanar conformation. Configurations are distinguishable from characteristic differences in the electronic and n.m.r. spectra.     

Preparation and structure of cobalt(II), nickel(II), copper(II) and zinc(II) complexes with 3-amino-5-(α/β)pyridyl-1, 2, 4-triazoles

Summary Complexes of bidentate 3-amino-5-()-pyridyl-1,2,4-triazole (L¹) and 3-amino-5-()-pyridyl-1, 2, 4-triazole (L²) of composition [ML¹Cl₂·H₂O], [ML²Cl₂·H₂O], [ML ₃ ^2/1 Cl₂] and [ML ₃ ^2/2 Cl₂] [M=Co^II, Ni^II, Cu^II, M=Zn^II] have been prepared and characterized by elemental analyses, i.r., u.v./visible, e.s.r. spectra, magnetic moments and molar conductances.     

Synthesis and spectral studies of chromium(III), cobalt(II) and nickel(II) complexes with phenylhydrazonoamidoxime

Summary Mononuclear complexes of chromium(III), nickel(II) and cobalt(II) derived from 3-oxo-2-phenylhydrazonobutane1-carbamidoxime (OPCA) were prepared and characterized by elemental analysis, molar conductance, magnetic susceptibility measurements and electronic and i.r. studies. The chromium(III) and nickel(II) ions form 1:2 complexes, whereas cobalt(II) forms a 1:1 complex in which the ligand chelates through the nitrogen of the amidoxime and the carbonyl oxygen. An octahedral structure is assigned to these complexes and the ligand field parameters such as Dq, B and were calculated. The nephelexautic parameter, , has values of 0.68, 0.84 and 0.78 for the chromium(III), cobalt(II) and nickel(II) complexes, respectively, suggesting the presence of covalent metal-ligand -bonds.     

Copper(II), nickel(II) and cobalt(II) complexes of 5,5-dimethylcyclohexane-1,2,3-trione-2-arylhydrazones

Summary Copper(II), nickel(II) and cobalt(II) perchlorate complexes of 5,5-dimethylcyclohexane-1,2,3-trione-2-(p-nitrophenyl-hydrazone) (HL¹), 5,5-dimethyl-cyclohexane-1,2,3-trione-2-(p-chlorophenylhydrazone) (HL²), 5,5-dimethylcyclohexane-1,2,3-trione-2-(o-chlorophenylhydrazone) (HL⁴), 5,5-dimethylcyclohexane-1,2,3-trione-2-(o-methylphenyl-hydrazone) (HL⁵) and 5,5-dimethylcyclohexane-1,2,3-trione-2-(m-methylphenylhydrazone) (HL⁶) have been prepared, and characterized using analytical, spectral and magnetic measurements. The data reveal that the reaction of Cu(ClO₄)₂ (1 mol) in EtOH, with all ligands, produces complexes of the type CuL(ClO₄)(H₂O).nH₂O. Nickel(II) and cobalt(II) perchlorates react only with HL¹ and HL² to produce the complexes ML(ClO₄)(H₂O)₃ (where M = Ni^II, L = L^– and L², M = Co^II, L = L¹) and Co(HL₂)₂-(ClO₄)₂.2H₂O. The spectral data show that the ligands behave as monobasic bidentate in their azo forms, except HL² which reacts with cobalt(II) as a neutral bidentate ligand in its hydrazone form.     

Complex formation between glycine and magnesium (II), calcium(II), and iron(II) at 25 °C in 3.00M NaClO4

Equilibria occurring between glycine (L) and magnesium(II) and calcium(II) were studied by measuring at 25 °C the electromotive force (e.m.f.) of the cell: (–) Pt, H₂/SolutionS/R.E. (+) where R.E. is the reference electrode described in the text.Equilibria taking place in solutions containing iron(II) and glycine were investigated by means of the cell: (–) R.E./SolutionS/G.E. (+) where G.E. is the glass electrode. The general composition of solutionS was in both cases the following: B M inM ²⁺;H M in H⁺;A M inL; 3.00M in ClO ₄ ^– ; (3-H-2B)M in Na⁺.Experimental data were explained by assuming the existence of the species:: MgL(log _1,0,1=1.53±0.05); MgL ₂(log _2,0,1=2.26±0.05); CaL(log _1,0,1==0.75±0.03); FeL(log _1,0,1=4.20±0.04).Protonation constants of aminoacetate, not known in the experimental conditions selected, were determined by means of e.m.f. measurements carried out with a H₂ electrode.

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Komplexbildung zwischen Glycin und Magnesium(II), Calcium(II), bzw. Eisen(II) bei 25 °C in 3,00M NaClO₄

Zusammenfassung Die Gleichgewichte zwischen Glycin (L) und Magnesium(II) bzw. Calcium(II) wurden bei 25 °C durch E.M.K. Messungen der folgenden Meßkette untersucht: (–) Pt, H₂/ProbenlösungS/R.E. (+) wobei R.E. Referenz-Elektrode bedeutet (siehe Text).Zum Studium der Reaktion zwischen Eisen(II) und Glycin bei 25 °C wurde folgende Meßkette benutzt: (–) R.E./ProbenlösungS/G.E. (+) wobei G.E. Glas-Elektrode bedeutet.Alle Meßproben hatten die folgende allgemeine Zusammensetzung:B M inM ²⁺;H M in H⁺;A M inL; 3,00M in ClO ₄ ^– ; (3-H-2B)M in Na⁺.Die experimentellen Daten konnten unter Annahme folgender Komplexe erklärt werden: MgL(log _1,0,1=1,53±0,05); MgL ₂(log _2,0,1=2,26±0,05); CaL(log _1,0,1=0,75±0,03); FeL(log _1,0,1=4,20±0,04). Die Protonierungskonstanten von Aminoacetat, die bei den gewählten experimentellen Bedingungen nicht bekannt sind, wurden mittels E.M.K. Messungen (mit Wasserstoff-Elektrode) bestimmt.

     

Etude des complexes sulfosalicylate de cuivre(III), nickel(II), cobalt(II) et uranyle(II) a l'aide d'une resine echangeuse de cations: Study of the sulphosalicylate complexes ofcopper(II), nickel(II), cobalt(II) and uranyl(II) by means of cation-exchange resins.

Study of the sulphosalicylate complexes of copper(II), nickel(II), cobalt(II) and uranyl(II) by means of cation-exchange resins.The conditional stability constants of the 1:1 complexes of the sulphosalicylate ions (L^3-) with copper(II), nickel(II), cobalt(II) and uranyl ions have been determined in a sodium perchlorate solution (0.1 M) and at various pH values by a cation-exchange method based on Schubert's procedure. The limits of application of the method are discussed. The variation with pH of the conditional stability constants can be explained by the existence of the complexes: CuH₂L, CuHL, CuL^-; NiH₂L⁺, NiHL, NiL^-; CoHL, CoL^-; UO₂H₂L⁺, UO₂HL, UO₂L^-, UO₂LOH^2-. The stability constants of these complexes are reported. Distribution diagrams of the various complexes of each element with pH and total concentration of sulphosalicylate parameters are given.     

Synthetic and kinetic studies on copper(II), nickel(II) and cobalt(III) complexes of 1,4,7,10,13-pentaazacyclohexadecane ([16]aneN5)

Summary The pentadentate macrocycle 1,4,7,10,13-penta-azacyclo-hexadecane [16]aneN₅=(3)=L} has been prepared and a variety of copper(II), nickel(II) and cobalt(III) complexes of the ligand characterised. The copper complex [CuL](ClO₄)₂, on the basis of its d-d spectrum, appears to be square pyramidal, while [NiL(H₂O)](ClO₄)₂ is octahedral. The copper(II) and nickel(II) complexes dissociate readily in acidic solution and these reactions have been studied kinetically. For the copper(II) complex, rate=k_H[complex][H⁺]² with k_H =4.8 dm⁶ mol^–2s^–1 at 25 °C and I=1.0 mol dm^–3 (NaClO₄) with H=43 kJ mol^–1 and S ₂₉₈ =–89 JK^–1 mol^–1. Dissociation rates of the copper(II) complexes increase with ring size in the order: [15]aneN₅ < [16]aneN₅ < [17]aneN₅. For the dissociation of the nickel(II) complex, rate=k_H[Complex][H⁺] with k_H=9.4×10^–3 dm³mol^–1 s^–1 at 25 °C and I =1.0 mol dm^–3 (NaClO₄) with H=71 kJ mol^–1 and S ₂₉₈ =–47 JK^–1mol^–1.The cobalt(III) complexes, [CoLCl](ClO₄)₂, [CoL(H₂O)]-(ClO₄)₃, [CoL(NO₂)](ClO₄)₂, [CoL(DMF)](ClO₄)₃ (DMF=dimethylformamide) and [CoL(O₂CH)](ClO₄)₂ have been characterised. The chloropentamine [CoCl([16]aneN₅)]²⁺ undergoes rapid base hydrolysis with k_OH=1.1× 10⁵dm³ mol^–1s^–1 at 25°C and I=0.1 mol dm^–3 (H=73 kJ mol^–1 and S ₂₉₈ =98 JK^–1 mol^–1). Rapid base hydrolysis of [CoL(NO₂)]²⁺ is also observed and the origins of these effects are considered in detail.     

Synthesis and characterization of cobalt(II), nickel(II), copper(II) and zinc(II) complexes with acetylacetone bis-benzoylhydrazone and acetylacetone bis-isonicotinoylhydrazone

Summary Acetylacetone bis-benzoylhydrazone (PhCONHN=CMe)₂ CH₂(LH₂) and acetylacetone bis-isonicotinoylhydrazone (NC₅H₄CONHN=CMe)₂CH₂(LH₂) complexes of the types [ML] and [ML] (M = Co^II, Ni^II, Cu^II or Zn^II) have been prepared and characterized. All the complexes are non-electrolytes and the cobalt(II) complexes are lowspin, the nickel(II) complexes are diamagnetic and the copper(II) complexes are paramagnetic. The ligands chelate via two C=N groups and two deprotonated enolate groups. The e.s.r. spectra of the copper(II) complexes indicate a tetragonally distorted dimeric structure. The X-ray diffraction parameters for [CoL] and [NiL] correspond to a tetragonal crystal lattice.     

Solvent extraction of lanthanide ions with 1-phenyl-3-methyl-4-benzoyl-pyrazolone-5 (HPMBP), II. Extraction of erbium(III), ytterbium(III) and lutetium(III) by HPMBP from aqueous-methanol solutions

The solvent extraction of lanthanides(III) (Ln=Er, Yb, Lu) by 1-phenyl-3-methyl-4-benzoylpyrazolone-5 (HL) in carbon tetrachloride from aqueous-methanol phase was investigated. The equilibrium constants for the extraction from aqueous –50% (v/v) methanol phase (K _ex ), two-phase stability constants of the complexesLnL ₃ ( ₃ ^* ) and stability constants of complexesLnL ²⁺,LnL ₂ ⁺ ,LnL ₃ ( _n ) (Ln=Yb, Lu) were calculated. It was confirmed that the addition of methanol to the aqueous phase causes a synergistic effect. The influence of methanol on the dissociation constant of HPMBP (K _a ) and the distribution constant of HPMBP (p _HL ) between carbon tetrachloride and water-methanol solutions was investigated.

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Extraktion von Seltenerdmetall-Ionen mit 1-Phenyl-3-methyl-4-benzoyl-pyrazolon-5 (HPMBP), II. Extraktion von Er(III), Yb(III) und Lu(III) aus Wasser-Methanol-Lösungen

Zusammenfassung Die Extraktion von Lanthaniden (Ln=Er, Yb, Lu) mittels 1-Phenyl-3-methyl-4-benzoyl-pyrazolon-5 (HL) in Kohlenstofftetrachlorid aus Wasser-Methanol Phase wurde untersucht. Die Werte der Gleichgewichtskonstante für Extraktion aus Wasser –50% (v/v) Methanol-Phase (K _ex ), der zweiphasigen Beständigkeitskonstante für die KomplexeLnL ₃ ( ₃ ^* ), sowie der Stabilitätskonstante des KomplexesLnL ²⁺,LnL ₂ ⁺ undLnL ₃ ( _n ) (Ln=Yb, Lu), wurden berechnet. Es wurde festgestellt, daß die Zugabe von Methanol zur wäßrigen Phase einen synergistischen Effekt hat. Der Einfluß von Methanol auf die Dissoziationskonstante von HPMBP (K _a ) und die Verteilungskonstante des HPMBP (p _HL zwischen organischer und wäßrig-methanolischer Phase wurde untersucht.

     

Violurato complexes of nickel(II). Formation equilibria. Deprotonation equilibria of the coordinated ligands and related stereochemical changes

Summary The formation equilibria of nickel(II) violurato-complexes in water and dimethylsulphoxide-water (8020) as well as deprotonation of the coordinated ligands and related stereochemical changes are reported. The stability constants of the Ni²⁺-H₂V^– complexes log₁=5.06, Iog₂=9.38, log₃=12.98 as well as the acidity constants of the [Ni(H₂V)₃]^– complex, log_j1= 8.37, log_j2=15.76, log_j3=22.37 are determined at 25 °C and 0.1M NaClO₄. A new violurato-complex of Ni²⁺, Na₄[Ni(HV)₃]5H₂O, is isolated and characterized.     

Synthesis,structures, and urease inhibition of nickel(II), zinc(II), and cobalt(II) complexes with similar hydroxy-rich Schiff bases

Four new nickel(II), zinc(II), and cobalt(II) complexes, [Zn(L¹)₂]?·?H₂O (1), [Ni(L¹)₂]?·?H₂O (2), [Ni(L²)₂] (3), and [Co(L³)₂]?·?H₂O (4), derived from hydroxy-rich Schiff bases 2-{[1-(5-chloro-2-hydroxyphenyl)methylidene]amino}-2-methylpropane-1,3-diol (HL¹), 2-{[1-(2-hydroxy-3-methoxyphenyl)methylidene]amino}-2-ethylpropane-1,3-diol (HL²), and 2-{[1-(5-bromo-2-hydroxyphenyl)methylidene]amino}-2-methylpropane-1,3-diol (HL³) have been synthesized and characterized by elemental analyses, infrared spectroscopy, and single-crystal X-ray determination. Each metal in the complexes is six-coordinate in a distorted octahedral coordination. The Schiff bases coordinate to the metal atoms through the imino N, phenolate O, and one hydroxyl O. In the crystal structures of HL¹ and the complexes, molecules are linked through intermolecular O–H···O hydrogen bonds, forming 1-D chains. The urease inhibitory activities of the compounds were evaluated and molecular docking study of the compounds with the Helicobacter pylori urease was performed.     

Preparation and x-ray crystal structure of a seven-coordinate cobalt(II) complex with 2,6-diacetylpyridine bis(2-picolinoylhydrazone)

Summary A new seven-coordinate cobalt(II) complex has been synthesized with 2,6-diacetylpyridine bis(2-picolinoylhydrazone) (H₂dappc) and its crystal and molecular structure has been determined by x-ray diffraction methods from counter data and refined toR 0.0449 for 2128 observed reflections. The complex crystallizes in a triclinic cell, space group P¯1, with dimensions:a=13.759(8),b=7.685(3),c=13.816(7) Å, =86.50(5), =66.48(5), =85.28(5)° andZ=2. The complete structure consists of [Co(H₂dappc)(OH₂)₂] cations, chloride anions and solvating H₂O molecules, interlinked by hydrogen bonds. The geometry around the cobalt is that of a distorted pentagonal bipyramid with the H₂dappc ligand forming the equatorial plane and two H₂O molecules occupying the axial positions.     

Synthesis and crystal structures of cobalt(III) and zinc(II) complexes with Schiff bases

Two new cobalt(III) and zinc(II) complexes, [Co(L¹)₂ (H₂O)] · ClO₄ (I) and [Ni(L²)₂ (H₂O)₂] · 2ClO₄ (II), where L¹ is the deprotonated form of 5-methoxy-2-[(2-morpholin-4-ylethylimino)methyl]phenol, and L² is the zwitterionic form of 2-[(2-isopropylaminoethylimino)methyl]-5-methoxyphenol, were synthesized and structurally characterized by elemental analyses, IR spectra, and single-crystal X-ray diffraction. The crystal of I is monoclinic: space group P2₁/c, a = 11.1512(4), b = 28.2424(11), c = 10.9655(4) Å, β = 95.746(2)°, V = 3436.1(2) ų, Z = 4. The crystal of II is triclinic: space group P2₁/c, a = 8.1441(2), b = 10.4531(3), c = 10.8849(3) Å, α = 84.0240(10)°, β = 76.9800(10)°, γ = 74.2280(10)°, V = 867.92(4) ų, Z = 1. Complex I consists of a mononuclear cobalt(III) complex cation and a perchlorate anion. Complex II consists of a crystallographic centrosymmetric mononuclear nickel(II) complex cation and two perchlorate anions. Each metal atom in the complexes is in an octahedral coordination.     

Komplexe von Cu(II), Zn(II), Ni(II) und Mn(II) mit N-m-Tolyl-p-methylbenzhydroxamsäure

The thermodynamic proton ligand and metal ligand stability constants of N-m-tolyl-p-methylbenzohydroxamic acid with Cu(II), Zn(II), Ni(II), and Mn(II) have been determined at 25° and 35° in several dioxane-water media. The pK _a and logK ₁ (logK ₂ or log ₂) varies linearly with the mole fraction of dioxane at a given temperature but not linearly with the reciprocal of dielectric constants of the medium. Values of G ^o, H ^o, and S ^o are tubulated. The stabilities of the complexes mostly follow the order of electron affinities of the metal ions. An attempt has been made to calculate the ligand field stabilization energy of the complexes.

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Mit 2 Abbildungen     

Solvent extraction of lanthanide ions with 1-phenyl-3-methyl-4-benzoyl-pyrazolone-5 (HPMBP), III: Extraction of gadolinium(III), terbium(III), dysprosium(III), holimum(III), and thulium(III) byHPMBP from aqueous solutions

Summary The solvent extraction behaviour of Gd(III), Tb(III), Dy(III), Ho(III), and Tm(III) has been investigated using 1-phenyl-3-methyl-4-benzoyl-pyrazolone-5 (HPMBP or HL) in carbon tetrachloride as the extractant. Depending on the concentration ofHPMBP in the organic phase the chelatesLnL ₃ [Ln(III)=Gd, Tb, Dy, Ho, Tm] and adductsLnL ₃ · HL [Ln(III)=Gd, Tb, Dy, Ho] were extracted. The extraction equilibrium constants (K _ex3 orK _ex4) for the formation ofLnL ₃ orLnL ₃ · HL and the two-phase stability constants of the chelates or adducts ( ₃ ^x , ₄ ^x ) have been evaluated.

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Extraktion von Seltenerdmetall-Ionen mit 1-Phenyl-3-methyl-4-benzoyl-prazolon-5(HPMBP), 3. Mitt.: Extraktion von Gd(III), Tb(III), Dy(III), Ho(III), und Tm(III) aus wäßrigen Lösungen

Zusammenfassung Die Extraktion von Gd(III), Tb(III), Dy(III), Ho(III), und Tm(III) mittels 1-Phenyl-3-methyl-4-benzoyl-pyrazolon-5 (HPMBP oderHL) in Kohlenstofftetrachlorid wurde untersucht. In Abhängigkeit von der Konzentration anHPMBP in der organischen Phase bildeten sich Chelate vom TypLnL ₃ [Ln(III)=Gd, Tb, Dy, Ho, Tm] and Addukte vom TypLnL ₃ · HL [Ln(III)=Gd, Tb, Dy, Ho]. Die Werte der Extraktions-Gleichgewichtskonstanten (K _ex3 oderK _ex4) fürLnL ₃ oderLnL ₃ · HL, sowie die Zweiphasen-Beständigkeitskonstanten ( ₃ ^x , ₄ ^x ) der Chelate oder Addukte wurden berechnet.

     

Complexation of cobalt(II) perchlorate with crown ethers. Synthesis,properties and structure of complexes of cobalt(II) perchlorate with 16-crown-5 and its lariat derivatives

Complexes of cobalt(II) perchlorate with 16-crown-5 (L¹) and its two lariat derivatives, 15,15-dimethyl-16-crown-5 (L²) and 15-(2,5-dioxahexyl)-15-methyl-16-crown-5 (L³), have been prepared and characterized. The crystal structure of [Co(L³)H₂O)](ClO₄)_{_2} has been determined by X-ray crystallography. The cobalt(II) ion is heptacoordinated with five crown ether oxygen atoms at the equatorial plane, a side arm oxygen atom and a water molecule at the apical position. The coordination polyhedron of cobalt is a distorted pentagonal bipyramid with the average Co-O(crown) distance of 2.20(2)Å.