Beitrag zum problem der bandenverschiebungen in den ir-spektren von dialkyldithiocarbamidaten: Teil V. Pyrroldithiocarboxylate. Der bereich von 500—32 cm-1

The far i-r. spectra of the pyrroledithiocarboxylates of Ni, Cu, Zn, Cd, Hg(II) and Pb are described. Evaluation of the spectra by means of the relative absorptions of the bands below 400 cm^-1 allows these chelates to be classified in terms of the coordination of the central metal atom. The characteristic value used for classification (the quotient of the absorption at the M-S frequency and the absorption at the strongest remaining band in the far i.r.) covers the range 0.6–2.1 for tetrahedrally coordinated chelates, and 8.7–10 for planar chelates. The characteristic values for the pyrroledithiocarboxylates, diethyl-and tetramethylene-dithiocarbamates and cupferronates, are compared.     

The infrared spectra (3500—150 cm-1) of aniline complexes of cobalt(II), nickel(II), copper(II) and zinc(II) halides

The IR spectra (3500—150 cm^?1) of the complexes [M(aniline)₂,X₂ (M = Co, Ni, Cu, Zn; X = Cl, Br), [Zn(aniline)₂I₂] are discussed. Assignments of the internal ligand vibrations are based on the band shifts which result from ¹⁵N-labelling of the amino group. The metal—ligand stretching frequencies, ν(M—N) and ν(M—X), are assigned on the basis of the band shifts which occur on ¹⁵N-labelling and metal ion and halogen substitution. Two bands within the range 350–450 cm^?1 are assigned to ν(M—N) while the ν(M—X) bands occur within the range 170–320 cm^?1. The effects of structure and coordination number on ν(M—N) and ν(M—X) are discussed. The spectra of two ethanol adducts, [M(aniline)₂-(ethanol)₂Cl₂] (M = Co, Ni) compared with those of the unsolvated species [M(aniline)₂-Cl₂], exhibit a unique band near 480 cm^?1 which is insensitive to ¹⁵N-labelling and is assigned to ν(M—O).     

The infrared spectra (600-140 cm−1 of the imidazole,pyrazine and pyrimidine adducts of cobalt(II), nickel(II) and zinc(II) acetylacetonates

Summary The complexes M(acac)₂(imidazole)₂ (M = Co or NO and [M(acac)₂B]_n (M = Co, Ni or Zn; B = pyrazine or pyrimidine) have been prepared and their i.r. spectra determined over the 600–140 cm^–1. range. The metal-oxygen and metal-nitrogen stretching frequencies, (M-O) and v(M-N), are assigned on the basis of the band shifts induced by deuteriation of the adducted base and by substitution of the metal ion. Three or fourv(M-O) bands are observed within the 600-200 cm^–1 range. The twov(M-O) bands of higher frequency are considered to the coupled with internal ligand modes. TwovM-N) bands are observed within the 280–170 cm^–1. range. The metal-ligand stretching frequencies are in good agreement with the values previously established for these vibrations in the [M(imidazole)₆]²⁺ and Ni(acac)₂(pyridine)₂ complexes.     

Dimeric tetrahedral complexes of manganese(II) and iron(II) with benzoyl hydrazones

Summary Dimeric manganese(II)and iron(II)complexes, (ML)₂, derived from benzoyl hydrazones ofo-hydroxyaryl aldehydes and ketones arc described and characterised by elemental analyses and by conductance, molecular weight, magnetic, electronic and i.r. spectral measurements. The dimeric nature of the complexes is revealed by i.r. spectra which show bands atca. 885 Mn²⁺ and 820 cm^–1 Fe²⁺, characteristic of ring vibrations. The i.r. spectra reveal the terdentate nature of the ligands. The electronic spectra in dimethylformamide are consistent with the tetrahedral nature of the complexes. The appreciable lowering in _eff is attributed to the presence of exchange interactions between two paramagnetic atomsvia oxygen bridges.Reprints of this article are not available.     

Metal Complexes with Novel Ambidentate Ligands: β-Enaminovinylketones with Annelated 1,2-Benzothiazine-1,1-Dioxide Fragment and Antipyrine Substituent

The data on competitive binding of ligands in metal complexes with ambidentate ligands (Schiff bases and -aminovinylketones) were summarized. Special attention is given to chemical and electrochemical syntheses and structural study of novel chelates of heterocyclic enaminoketones with antipyrine substituent that form tetrahedral (Cu²⁺, Zn²⁺) or octahedral (Co²⁺, Ni²⁺) structures.     

The infrared spectra (3500-140 cm−1) of the 2,2'-bipyridine, 2-aminomethylpyridine and ethylenediamine adducts and the sodium tris-compounds of cobalt(II), nickel(II) and zinc(II) acetylacetonates

Summary The M(acac)₂B and NaM(acac)₃ complexes (M = Coll, Ni^ll orZn^ll; acac=acetylacetonateanion; B=2,2=bipyridine, 2-aminomethylpyridine or ethylenediamine) have been prepared and their i.r. spectra determined over the 3500-140 cm^–1 range. Complete band assignments have been made on a comparative basis, with the effects of ligand substitution and metal ion substitution being considered. Bands in the i.r. spectra of the complexes which are associated with 2,2-bipyridine, 2-aminomethylpyridine and ethylenediamine arc in excellent agreement with values previously established for these ligand and metal-ligand vibrations, in related complexes. Band assignments for acetylacetonate anion and metal-acetylacetonate vibrations substantiate those made in certain of the previously published papers. The method of assignment adopted has allowed the complete assignment of bands in the i.r. spectra of the metal complexes.     

Darstellung und spektroskopische Eigenschaften der gemischtvalenten Di(phthalocyaninato)lanthanide(III)

Synthesis and Spectroscopical Properties of the Mixed-Valent Di(phthalocyaninato)lanthanides(III) Green di(phthalocyaninato)lanthanide(III), [M(Pc)₂] (M = rare earth metal ion: La‥(-Ce, Pm)‥Lu) is prepared by anodic oxidation of (ⁿBu₄N)[M(Pc^2?)₂] dissolved in CH₂Cl₂/(ⁿBu₄N)ClO₄. The UV-Vis-NIR spectra show intense π-π* transitions at ? 15000 cm^?1 and 31000 cm^?1, typical for Pc^2? ligands. Bands at ? 11000 cm^?1 and 22000 cm^?1 indicate the equal presence of a Pc^? π-radical. The metal dependent NIR band between 4000 and 9000 cm^?1 is characteristic for these mixed-valent complexes and assigned to an intervalence transition (b₁ → a₂; D_4d symmetry). Most bands are shifted linearly with the M^III radius. In the IR and resonance Raman (r.r.) spectra the typical vibrations of the Pc^? π-radical are dominant. These are essentially metal independent excepting the C? C and C? N vibrations of the inner (CN)₈ ring. The sym. M? N stretching vibration between 141 (La) and 168 cm^?1 (Lu) is selectively r.r.-enhanced when excited with 1064 nm.     

Mononuclear and binuclear chelates of biacetylmonoxime picolinoylhydrazone

Mononuclear and binuclear chelates of biacetylmonoxime picolinoylhydrazone (H₂BMPcH) with Cr^III, Fe^III, Co^II, Ni^II, Cu^II, Zn^II, Cd^II, Pd^II and UO₂ ²⁺ have been prepared. Elemental analyses, molar conductivities, spectral (u.v., visible, i.r., n.m.r., e.s.r.), thermal (t.g., d.t.g., d.t.a.) and magnetic susceptibility measurements have been used to characterize the chelates. The i.r. spectral data indicate that H₂BMPcH behaves in a bidentate, tridentate and/or tetradentate manner and the hydrazonic azomethine nitrogen constituents the chelating backbone in all chelates. Based on magnetic and spectroscopic data, the structures for the chelates are proposed as follows: tetrahedral for [Co(HBMPcH)(H₂O)]Cl, octahedral for [Co(HBMPcH)₂], [Cr(HBMPcH)Cl(H₂O)]₂Cl₂, [Fe(HBMPcH)Cl-(H₂O)]₂Cl2, [Ni(BMPcH)(H2O)2], square-planar for (Ni(HBMPcH)Cl], [Pd(HBMPcH)Cl], [Cu(HBMPcH)(H2O)]Cl and tetragonally distorted octahedral for [Cu(BMPcH)(H2O)2]2 chelates. Generally, the solid metal acetate complexes have a unique decomposition exotherm profile which can be used as a rapid and sensitive tool for the detection of acetate-containing complexes.     

Die Chelate von Co(II), Ni(II), Cu(II), Zn(II) und Cd(II) mit Malonsäurehydrazid und dessen Arylidenderivaten

The metal chelates formed by the reaction of Co²⁺, Cu²⁺, Ni²⁺, Zn²⁺, and Cd²⁺ with malonic hydrazide and its arylidene derivatives are investigated. The i.r.-absorption spectra of the solid compounds supported the tetradentate character of these compounds; they also show that the ligand still attained the keto form. The shift of the C=O, C=N bands is utilized in determining the coordination bond length. The stoichiometry of the metal complexes, as studied by spectrophotometric and conductometric methods, is found to be metal ion: ligand =11. The apparent formation constants of the malonic hydrazide complexes are also determined.

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Metal chelates of 1-acetylpyridinium chloride-4-phenyl-3-thiosemicarbazide

The metal chelates of 1-acetylpyridinium chloride-4-phenyl-3-thiosemicarbazide [(APTS)]⁺Cl^? of the type [M(APTS)X₂]⁺ Cl^? (M = Co(II), Ni(II), Cu(II), Zn(II) or Cd(II); X = Cl, Br or $\text{1}\text{2}$SO₄) have been prepared and characterized on the basis of elemental analysis, molar conductance, IR, electronic spectra and magnetic studies. IR spectral studies showed that the ligand coordinates via thioketo and NLH groups. Magnetic and spectral studies suggest a tetrahedral structure for Ni(II), pseudo-tetrahedral for Co(II) and square planar and/or distorted tetrahedral for Cu(II) chelates.     

Resacetophenone-furfural polymers

Poly(resacetophenone-furfural) was prepared by condensing resacetophenone with furfural in the presence of the optimum concentrations of various acidic catalysts. The polymer samples were characterized by elemental analyses, i.r. spectra and TGA. The number-average molecular weights were determined both by vapour pressure osmometry and non-aqueous titration. Intrinsic viscosities of the polymers were measured in DMF. Polymeric metal chelates of Cu²⁺, Fe³⁺, Co²⁺, Zn²⁺, Mn²⁺, Ni²⁺ were prepared and characterized.     

The far infrared spectra of metal chloride complexes of pyridine in relation to their structures

The infrared spectra of the complexes [M(py)₂Cl₂] (py = pyridine; M = Mn, Fe, Co, Ni, Cu, Zn) have been determined within the range 650–150 cm^?1. Assignments of the metal—nitrogen and metal—halogen stretching frequencies (vM—N and vM—Cl) are made on the basis of the band shifts induced by deuteration of the pyridine ring and by varying the coordinated metal ion. If the band of lowest frequency is assigned to a bending mode, the number of vM—N and vM—Cl bands observed agrees with the number required by symmetry considerations based on the known structures of the complexes. On the basis of this work, some earlier assignments have been revised.     

Spectroscopic investigation of the cobalt(II), nickel(II), copper(II) and zinc(II) tetrahalometallates of theN-ethylmorpholinum cation

Summary Tetrahalometallates of the type (Etmorphl1)21MX4 (M = Co¹¹, Ni¹¹ or Zn¹¹ and with X = Cl, Br or l; M = Cu^II with X = CI or Br) and mixed tetrahalocuprates, Etmorphll)₂[CUX_mY_4–m] (X = Cl; N' = 13r; m = 1,2,3) of theN-ethylmorpholinium cation were prepared and investigated by means of spectroscopic and magnetic measurements. While the cobalt(II), nickel(II) and zinc(II) complexes appear to be essentially, tetrahedral, the copper(II) complexes are discussed on the basis of a distorted ('flattened') tetrahedral symmetry. The electronic spectra of the complexes are assigned on this basis. The far i.r. spectra of the complexes show bands which are unambiguously assignable to the metal-halogen stretching modes. The effects of the counter cation on the geometry around the metal ion, compared with that of the morpholinium and piperidinium cations, are discussed in relation to the pK_a of the amine.     

Structure of NR<Subscript>4</Subscript>BR-H<Subscript>2</Subscript>O and CoBr<Subscript>2</Subscript>-NR<Subscript>4</Subscript>BR-H<Subscript>2</Subscript>O solutions according to electronic and IR spectroscopy data

Absorption spectra of NR₄Br-H₂O and CoBr₂-NR₄Br-H₂O (R = Et, Bu) aqueous solutions were measured within the range of 1000–25000 cm⁻¹, and the influence of tetraalkylammonium cations on the equilibrium between cobalt octahedral and tetrahedral complexes was revealed. The specificity of hydration interactions in solutions under study in various concentration ranges and resulting from them difference in spectral characteristics were analyzed. Variously directed changes in positions of bands in the region of stretching vibrations, a composite frequency of 5200 cm⁻¹, and the first water overtone occurring due to the concentration variation were found.     

Complexes of 8-Aminoouinoline. II. The Infrared Spectra of the Bisand Mono(Aminoquinoline) Complexes of Metal(II) Halides

Abstract

The infrared spectra of the complexes M(aq)₂(H₂O)₂X₂ (M = Fe, Co, Ni, Cu; aq = 8-aminoquinoline; X =Cl, Br) have been determined over the range 4000-50 cm^?1. Absence of vM-X bands indicates that the halide is not coordinated to the metal ion and the complexes are correctly formulated [M(aq)₂-(H₂O)₂]X₂. Deuteration of the amino group and the effects of metal ion substitution enable assignment of the vM-NH₂, vM-N and vM-OH₂ modes as well as the amino group vibrations. ¹⁸ O-Labelling assists in identifying the vO-H, vO-H……X and δO-H bands. The spectra are consistent with trans-octahedral coordination and axial bonding of the water molecules. The far infrared spectra of the mono(aminoquinoline) complexes [M(aq)X₂]_n (M = Cu, Zn; X = Cl, Br) are consistent with the proposed structure of polymeric octahedral coordination involving both bridging and terminal M-X bonds. The vM-NH₂, vM-N, vM-X(terminal) and vM-X(bridging) bands are assigned by studying the effects of amino group deuteration, metal ion substitution and halide substitution.     

Behaviour of Li+ and Cu2+ in heated montmorillonite: Evidence from far-, mid-, and near-IR regions

Infrared spectroscopy in the far (FIR), mid (MIR), and near (NIR) regions was used to study the structural changes of a thermally treated clay mineral montmorillonite saturated with Li⁺ or Cu²⁺ cations (Li-JP and Cu-JP samples). Cation exchange capacity (CEC) values decreased by 89 and 64% in Li- and Cu-samples, respectively, heated at 300 °C. The IR spectra confirm that the charge of exchangeable cations significantly affect their final position after fixation upon heating. No absorption bands related to the vibrations of interlayer cations were observed in the FIR spectra of unheated or heated samples; however, different modification of the complex vibrational mode involving motion of octahedral aluminium relative to the tetrahedral sheet was observed near 197 cm⁻¹. The vibrations of OH groups in both MIR (ν_OH, 3630–3670 cm⁻¹) and NIR (2ν_OH, 7070–7170 cm⁻¹) regions proved that the Li⁺ migrated into the octahedral vacancies, thus creating local trioctahedral domains, such as AlMgLiOH. Though Cu²⁺ has similar ionic radius as Li⁺, no spectral features indicating its presence in the octahedral positions have been found even in the sample heated at 300 °C. Fixed Cu(II) is supposed to be located deep in the ditrigonal cavities of the tetrahedral sheets of Cu-JP. The NIR spectra of heated Cu-JP samples show new components near 7045 and 5170 cm⁻¹. These modes are believed to correspond to overtone bands associated with hydrated Cu²⁺ ions tightly bound in close proximity to the ditrigonal cavities of the basal surface (O_basalCu²⁺H₂O). The NIR spectra confirm that in Cu-JP heated at 200 °C, then saturated with Li⁺ and Cu²⁺ and heated again at 300 °C small Li⁺ ions migrate into the vacant octahedral sites even though Cu(II) have been trapped in the hexagonal cavities of the tetrahedral sheets in the course of previous heat treatment.     

Complexes of divalent oxovanadium,manganese, iron,cobalt, nickel and copper with the ligand derived from the reaction of 2-aminopyridine and acetylacetone

Summary 2-Aminopyridine reacts with acetylacetone in the presence of VO^II, Mn^II, Fe^II, Co^II, Ni^II, and Cu^II metal salts to give complexes of the type [VO(Ap₂ac)₂X]X and [M(Ap₂ac)₂X₂] where (Ap₂ac) is the ligand formedin situ. The complexes are characterised as distorted octahedral by analyses, conductance, molecular weight, magnetic, electronic and i.r. spectral studies. The i.r. studies reveal that two molecules of aminopyridine are joined by a molecule of acetylacetone through a three carbon atom bridge and that the ligand coordinates through the azomethine and imino nitrogen atoms, whereas pyridine does not take part in coordination. The electronic spectra have been interpreted and tentative assignments are made. In the far i.r. spectra, various metal ligand vibrations are observed and discussed. Attempts to carry out electrophilic substitutions in the complexes failed.     

Vibrational spectra of tellurates with the garnet structure

The IR and Raman spectra of tellurates Ln₃Te₂Li₃O₁₂ (Ln=Pr…Lu, Y), Ca₃Te₂Zn₃O₁₂ and Na₃Te₂M³⁺₃O₁₂ (M³⁺ = Al, Ga, Fe) with the garnet structure are presented and discussed on the basis of a group theoretical analysis, and of ⁶Li—⁷Li isotopic frequency shifts. The assignment of the high-frequency bands to stretching vibrations of the TeO₆ octahedra is only an approximation whose validity depends on the nature of the tetrahedral cation (Li, Zn or M³⁺) and of the symmetry properties of the vibrations: cationic mass effects play an important role in the antisymmetric, IR-active vibrations, whereas the bonding forces are the determining factor in the totally symmetric, Raman active vibrations. For the Na₃Te₂M³⁺₃O₁₂ garnets, the (TeO₆) internal modes approximation is unacceptable since the stretching frequencies of the TeO₆ and M³⁺O₄ groups are of the same order of magnitude. No detailed assignments are available for the medium-frequency bands: they are due in part to the bending vibrations of the TeO₆ octahedra, but the contribution of the tetrahedral cation Zn²⁺ or M³⁺ to this region of the spectrum remains largely unknown. The translational frequencies of the dodecahedral Ln³⁺ cations have been identified in the low frequency region (below 250 cm⁻¹) by comparison of the frequencies of the Ln and Y garnets.     

Coordination compounds of hydrazine derivatives with transition metals. Part 26. Coordination properties of α-diketone and α-ketoaldehyde bishydrazones derived from hydrazine-S-methylcarbodithioate

Summary Metal(II) chelates with -diketone and -ketoaldehyde bishydrazones derived from hydrazine-S-methylcarbodithioate with the general formula M[-dik(hydth)₂-2H] (M=Zn^II, Cd^II, Ni^II, Cu and Pd^II) were prepared and characterized by i.r., electronic and mass spectra as well as magnetic properties. The Ni^II, Zn^II and Cd^II chelates are most probably pentacoordinated dimers whereas the Cu^II chelates are polymeric through Cu-S linkages. The Pd^II chelates are square planar monomers.     

Infrared Spectra of α-Thenoyl-trifluoroacetonates of Metal Ions of the First Transition Series

The IR. spectra of α-thenoyl-trifluoroacetone (HTTA) and seventeen of its chelates with metal(II) and -(III) ions of the first transition series have been determined. Three series of complexes are represented: the anhydrous metal(II) species, [M(TTA)₂]_n (M ? Ca, Mn, Co, Ni, Cu, Zn); metal(II) dihydrates, [M(TTA)₂(H₂O)₂] (M ? Mn, Fe, Co, Ni, Zn); and the metal(III) chelates, [M(TTA)₃] (M ? Sc, V, Cr, Mn, Fe, Ga). For each metal(II) complex, the spectra of the anhydrous and hydrated compounds are practically identical, suggesting that the anhydrous complexes have the polynuclear octahedral structure established for the corresponding acetylacetonates. Magnetic moment determinations reveal that complexes of the 3d⁴?3d⁷ ions all have spin-free configuration. Several vibrational bands with frequencies < 700 cm^?1 are found to exhibit a frequency variation with d-orbital population which is consistent with the order of crystal field stabilization energies and hence with their assignment as coupled metal-oxygen stretching modes. Unique features of the spectra of [Cu(TTA)₂] and [Mn(TTA)₃] are ascribed to structural differences arising from Jahn-Teller distortion. Tentative assignments for the majority of the ligand vibrations are given.