Coordination compounds of N-(2-aminophenyl)- and N-(3-aminophenyl)pyridine-2′-carboxamide with cobalt(II) and cobalt(III). The nature of amide deprotonation induced by cobalt(III) in acidicpH

New complexes of the general formulae CoL ₂ X·nH₂O (X=Cl, Br, I, NCS, NO₃ andn=0, 1, 2 or 3), Co₂ L ₂ X ₃·EtOH (X=Cl, Br, I, NCS), Co(DH)X ₂ (X=NCS, NO₃) and Co(DH)₂ X ₂ (X=NCS, I) have been prepared, whereLH=N-(2-aminophenyl)pyridine-2-carboxamide andDH=N-(3-aminophenyl)pyridine-2-carboxamide. The compounds were characterized by X-ray powder patterns, conductivity measurements, thermogravimetric analysis, magnetic properties as well as by IR, ligand field and¹H-NMR spectroscopy. In the presence of oxygen,LH undergoes a cobalt(III) ion promoted amide hydrogen ionization in thepH region 4–6.

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Koordinationsverbindungen von N-(2-aminophenyl)- und N-(3-aminophenyl)pyridin-2-carboxamid mit Cobalt(II) und Cobalt(III). Die Natur der Deprotonierung von Amiden induziert von Cobalt(III) in saurem Medium

Zusammenfassung Neue Komplexe der allgemeinen Formeln CoL ₂ X·nH₂O (X=Cl, Br, I, NCS, NO₃ undn=0, 1, 2, 3), Co₂ L ₂ X ₃·EtOH (X=Cl, Br, I, NCS), Co(DH)X ₂ (X=NCS, NO₃) und Co(DH)₂ X ₂ (X=NCS, I) wurden dargestellt mit LH=N-(2-aminophenyl)pyridin-2-carboxamid undDH=N-(3-aminophenyl)pyridin-2-carboxamid. Die Verbindungen wurden mittels Röntgenstrukturanalyse, Leitfähigkeitsmessungen, thermogravimetrischen Analysen, magnetischen Eigenschaften sowie mit IR-, Ligandenfeld- und¹H-NMR-Spektroskopie charakterisiert. In Gegenwart von Sauerstoff unterliegtLH einer Cobalt(III)ion-induzierten Amidwasserstoffionisierung impH-Bereich 4–6.

     

Chemische Effekte des isomeren Überganges von Brom-80m in Pentamminkobalt(III)-und Bisäthylendiaminkobalt(III)-bromiden

Zusammenfassung Die chemischen Effekte des isomeren Überganges von^80mBr wurden bei Temperaturen von–78° C und–196° C an mit^80mBr markierten Proben von [Co(NH₃)₅ X]Br_3.2 nH₂O und [Co(en)₂ X _2']Br_3.1 nH₂O untersucht (X=NH₃, NCS, NO₂, OH₂, ONO, ONO₂, F, Cl, Br, I, undX'=en, NH₃, NCS, Cl, Br). Es zeigte sich, daß die Ligandenausbeute an⁸⁰Br, in den Komplexen mit abnehmender Frequenz des Maximums in der ersten Absorptionsbande des [Co(NH₃)₅ X] und des [Co(en)₂ X _2'] zunimmt. Mit anderen Worten, weniger stabile, Liganden werden leichter von Radiobrom ersetzt als Folge des isomeren Überganges in festen Komplexen.

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Chemical effects of the isomeric transition of^80mBr in pentammincobalt(III) and bisethylenediaminecobalt(III) bromides

The chemical effects of the isomeric transition of^80mBr were investigated at temperatures of–78° C and–196° C with^80mBr-labeled samples of [Co(NH₃)₅ X]Br_3.2 nH₂O and [Co(en)₂ X _2']Br_3.1 nH₂O (X=NH₃, NCS, NO₂, OH₂, ONO, ONO₂, F, Cl, Br, I, andX'=en, NH₃, NCS, Cl, Br). The ligand yield of⁸⁰Br in the complexes was found to increase with the decrease in the frequency of the maximum in the first absorption band of [Co(NH₃)₅ X] and [Co(en)₂ X _2']. In other words, less stable ligands were more easily replaced by radiobromine as a consequence of isomeric transition in solid complexes.

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Mit 1 Abbildung

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Herrn Prof. Dr.E. Broda zum 60. Geburtstag gewidmet.     

Synthesis,spectral and thermal characterization of 6-hydroxymethyl pyridine-2-carboxylic acid methyl ester and its complexes

New pincer ligand, 6-hydroxymethylpyridine-2-carboxylic acid methyl ester, HL, and its bipositive, tripositive and uranyl metal complexes have been synthesized and characterized by elemental and thermal analyses, IR, diffuse reflectance and ¹H NMR spectra, molar conductance and magnetic moment measurements. The downfield shift of the aliphatic OH signal (from 3.87 vs. 2.96 ppm in the ligand) upon complexation indicates the coordination by protonated aliphatic OH group. Zn(II) and UO2(II) complexes are found to be diamagnetic as expected. The low molar conductance values indicate that Ni(II) and Zn(II) complexes are non electrolytes; Fe(II), Co(II), Cu(II) and UO₂(II) complexes are 1:2  electrolytes while Fe(III) complex is a 1:3 electrolyte. The general compositions of the complexes are found to be [M(HL)X₂]·nH₂O where M=Ni(II) (X=Cl, n=1) and Zn(II) (X=Br, n=0); and [M(HL)₂]X_m·nH₂O where M=Fe(II) (X=Cl, m=2, n=0), Fe(III) (X=Cl, m=3, n=4), Co(II) (X=Cl, m=2, n=0), Cu(II) (X=Cl, m=2, n=0) and UO₂(II) (X=NO₃, m=2, n=0). The thermal behaviour of the complexes has been studied and different thermodynamic parameters are calculated using Coats-Redfern method.     

Thermal decomposition of octahedral Ni(II) complexes with acetone 1-naphthoylhydrazone

The thermal decompositions of acetone 1-naphthoylhydrazone (L) and its octahedral complexes with Ni(II), with the general formula NiL₂X₂ (X=Cl, Br, NO₃ and NCS), were studied in air and nitrogen atmospheres. It was established that the organic ligand is decomposed in an exothermic processes, which is followed by oxidation of the decomposition fragments by atmospheric oxygen. At temperatures below 640°, all the complexes decompose completely, yielding NiO as the final product, which was confirmed by its X-ray analysis. From the difference between the enthalpy changes for the decompositions of the complexes and of the ligand itself, the nature of the final oxide, and the crystal field splitting parameters obtained from optical measurements, the corresponding stabilization energies were determined.

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Zusammenfassung In Luft- und Stickstoffatmosphäre wurde die thermische Zersetzung von Azeton-1-naphthoylhydrazon (L) und seinen oktaedrischen Komplexen mit Ni(II) mit der allgemeinen Formel NiL₂X₂ (mit X=Cl, Br, NO₃ und NCS) untersucht. Es wurde festgestellt, daß der organische Ligand in einem exothemen Prozeß einer Zersetzung und einer anschließenden Oxydation der Zersetzungsprodukte durch Luftsauerstoff unterliegt. Unterhalb 640° zerfällen alle Komplexe vollständig und liefern NiO als Endprodukt, welches mittels Röntgendiffraktionsanalyse identifiziert wurde. Aus dem Unterschied zwischen Enthalpieänderungen für die Zersetzung der Komplexe und des Liganden selbst, aus der Art der erhaltenen Oxide und aus den Parametern der durch optische Messungen bestimmten Kristallfeldaufspaltung wurden die entsprechenden Stabilisierungsenergien bestimmt.

     

Thermal behaviour of platinum(II) complexes of diethyl and monoethyl 2-quinolylmethylphosphonates

Summary Thermal study of the molecular and ionic platinum(II) complexes of diethyl (2-dqmp) and monoethyl (2-Hmqmp) ester of 2­quinolylmethylphosphonic acid: dihalide adducts trans-PtL₂X₂ (L=2-dqmp, X=Cl, Br; L=2-Hmqmp, X=Cl), methylquinolinium tetrahaloplatinates [LH⁺]₂[PtX₄^2-] (L=2-dqmp, X=Cl, Br; L=2­Hmqmp, X=Cl, Br), methylquinolinium hexahalodiplatinates [LH⁺]₂[Pt₂X₆^2-](L=2-Hmqmp, X=Cl, Br) and chelate complex Pt(2­mqmp)₂·2H₂O, has been carried out using TG-DTA techniques and the infrared spectroscopic study. There are great differences in the thermal behaviour between various types of complexes, especially between the molecular and the ion-pair salt complexes.     

Transition metal chemistry of oxime containing ligands,VII

Complexes of pyridine-2-aldoxime (Hpox) with iron(II) and chromium(III) of type, [Fe(Hpox)₂ X ₂] (X=Cl, Br, I or NCS); [Cr(Hpox)₃]Cl₃·3 H₂O; [Cr(Hpox)₂ X ₂]ClO₄ (X=F, Cl or Br) and [Cr(Hpox)₂(H₂O)₂]Br₃·H₂O were prepared and characterized by analytical X-ray powder diffraction, magnetism, vibrational (conventional and far-infrared) and electronic spectroscopy techniques. X-ray and electronic spectral data indicate that all the complexes except [Cr(Hpox)₃]Cl₃·3 H₂O havetrans-pseudo-octahedral microsymmetry around the metal ion. Infrared spectral data indicate that the ligand, Hpox, behaves like a neutral ligand and coordinates to the metal ion through pyridine nitrogen atom and oxime nitrogen atom in all these complexes. The magnetic susceptibilities of chromium(III) complexes, measured over a temperature range 300–78 K, are independent of temperature whereas the magnetic moments of iron(II) complexes over a temperature range 300–20 K are dependent of temperature. The observed temperature dependence of magnetic moments of iron(II) complexes was used to evaluate the magnitude of orbital reduction factor,k, the low-symmetry distortion parameter, , and the extent of reduction in spin-orbital coupling, . In all these iron(II) complexes the magnetic results indicate the presence of an orbitally non-degenerate,⁵B_2g, ground state. Magnetically unperturbed and perturbedMössbauer spectra of iron(II) complexes at various temperatures have also been reported. Magnetically perturbedMössbauer spectra of iron(II) complexes at 4.2 K in an axial field of 60kGauss indicate that the principal component of electric field gradient tensor is positive and consistent with⁵B_2g ground electronic state in a tetragonal (D _4h) local site symmetry.

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Übergangsmetallkomplexe mit Oxim-enthaltenden Liganden, VII. Elektronische und strukturelle Eigenschaften vonFe(II)-undCr(III)-Komplexen mit Pyridin-2-aldoxim

Zusammenfassung Es wurden Komplexe von Pyridin-2-aldoxim (Hpox) mit Fe(II) und Cr(III) vom Typ [Fe(Hpox)₂ X ₂] (X=Cl, Br, I, NCS), [Cr(Hpox)₃]Cl₃·3 H₂O, [Cr(Hpox)₂ X ₂]ClO₄ (X=F, Cl, Br) und [Cr(Hpox)₂(H₂O)₂]Br₃·H₂O hergestellt. Charakterisierung und Diskussion von Geometrie und Bindungsverhalten in den Komplexen erfolgte auf Grund von analytischen Daten, Röntgen-Pulveraufnahmen, Elektronenanregungsspektroskopie, Infrarotspektroskopie, magnetischen Messungen undMössbauer-Spektroskopie.

     

Synthesis and characterization of cobalt(II) and iron(III) complexes with the Schiff bases:N-(p-methylbenzylidene)-2-aminobenzimidazole andN-(benzylidene)-2-(2′-aminophenyl)-benzimidazole

Summary Reactions of CoX₂ (X=Cl, Br or NCS) and FeCl₃ with the Schiff bases:N-(p-methylbenzylidene)-2-aminobenzimidazole (pmbabi) andN-(benzylidene)-2-(2-aminophenyl) benzimidazole (bapbi) yield complexes of general formula CoL₂X₂ [except for Co(bapbi)(NCS)₂] and FeLCl₃. All complexes have been characterized by elemental analyses, i.r. spectroscopy conductivity and magnetic measurements at different temperatures; solid state and solution electronic spectra are reported for cobalt(II) complexes. The results show that the latter are pseudotetrahedral, the ligand acting as monodentate, except for Co(bapbi) (NCS)₂. On the other hand, the iron compounds probably contain pentacoordinated metal.     

Thermal deamination of some complexes of the type [CO(Diox·H)2 (Amine)2]X

The thermal deamination of [Co(diox·H)₂(amine)₂]X type complexes were studied in dynamic temperature conditions (diox·H₂ stands for 1,2-cycloheptanedione dioxime (heptoxime, heptox·H₂) and 1,2-cyclo-octanedione dioxime (octoxime, octox·H₂), amine for aniline and pyridine,X for Br, I and NCS). Kinetic parametersn, E and logZ have been derived for some derivatives by means of two computerized integral methods. The influence of the sample weight, heating rate and chemical constitution upon the kinetic parameters, as well as the kinetic compensation effect are discussed.

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Thermische Desaminierung einiger Komplexe des Typs [Co(Diox·H) ₂ (Amin₂]X. Über -Dioximinkomplexe der Übergangsmetalle, LXIV.

Zusammenfassung Die thermische Desaminierung einiger Komplexe des Typs [Co (Diox·H)₂(Amin)₂]X wurde bei dynamischen Temperaturbedingungen untersucht [Diox·H₂ bedeutet 1,2-Cycloheptandiondioxim, (Heptoxim, Heptox·H₂) und 1,2-Cyclooctandiondioxim (Octoxim, Octox·H₂), Amin bedeutet Anilin und Pyridin,X bedeutet Br, I, bzw. NCS]. Die kinetische Parametern, E und logZ wurden mit Hilfe von zwei computergeeigneten Integralmethoden bestimmt. Der Einfluß des Gewichtes der Proben, der Heizungsgeschwindigkeit und der chemischen Zusammensetzung auf die kinetischen Parameter, bzw. der kinetische Kompensationseffekt werden diskutiert.

     

The relationship between the structures of Cu(ii) coordination compounds and their thermal decomposition

A study was made of the influence of the composition of the Cu(II) coordination sphere on the course of the thermal decomposition of the complexes Cu₄O(X+Y)₆L₄, whereX andY were Cl and Br, andL was piperidine or morpholine. The tetrahedral unit Cu₄O with the oxygen atom in its centre was found to be the thermally weakest part of the complex. The decomposition temperatures of the complexes were strongly influenced by the anionsX andY and by the ligandL. The temperature at which decomposition started was found to be the lower, the more chloride anions were substituted by bromide anions. The complexes containing piperidine as ligandL exhibited higher decomposition temperatures than those with morpholine as ligand. The decompositions of all the studied complexes were accompanied by redox reactions. The only compounds identified among the decomposition intermediates by X-ray diffraction were copper(I) halides. Copper(I) bromide underwent oxidation on further heating and a mixture of CuO and CuBr was obtained as the final decomposition product.

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Zusammenfassung Bei der thermischen Zersetzung von Komplexen der Formel Cu₄O(X+Y)₆L₄ mitX,Y=Cl bzw. Br undL= Piperidin oder Morpholin wurde der Einfluß der Zusammensetzung der Cu(II)-Koordinationssphäre auf den Verlauf der thermischen Zersetzung untersucht. Als thermisch schwächstes Glied des Komplexes wurde die tetraedrische Einheit Cu₄O mit dem Sauerstoffatom im Zentrum befunden. Die Zersetzungstemperaturen der Komplexe werden durch die AnionenX undY sowie durch die LigandenL wesentlich beeinflußt. Die Temperatur, bei der die Zersetzung einsetzt liegt um so niedriger, je mehr Chloridanionen durch Bromidanionen ersetzt werden. Komplexe mit Piperidin als Ligand zeigen höhere Zersetzungstemperaturen als mit dem Ligand Morpholin. Die Zersetzung aller Komplexe ist von Redoxreaktionen begleitet. Die einzigen Verbindungen, die unter den Zersetzungsprodukten mittels Röntgendiffraktion identifiziert wurden, waren Kupfer(I)-halogenide. Kupfer(I)-bromid unterliegt bei weiterem Erhitzen einer Oxidation und man erhält letztendlich ein Gemisch aus CuO und CuBr als Zersetzungsprodukt.

     

Dinuclear trivalent chromium,manganese, iron and cobalt complexes bridged by aromatic diamines

Summary Trivalent chromium, manganese, iron and cobalt salts react withm-phenylenediamine and acetylacetone to give complexes of the type [M(C₁₆H₁₈N₂O₂)X]: X = Cl, Br, NO₃ or NCS for M = chromium(III) and iron(III); X = Cl, Br, OAc or NCS for manganese(III); and X = OH for cobalt(III). Conductance measurements show the complexes to be nonelectrolytes. Molecular weights determined cryoscopically, show the iron complexes to be dinuclear. Magnetic measurements above 85 K reveal the presence of slight antiferromagnetic interactions. The complexes are dimeric five-coordinate square-pyramidal withm-phenylenediamine residues acting as bridges. The electronic spectra are interpreted in terms of the Normalised Spherical Harmonic Hamiltonian Theory and the DT/DQ values which indicate that chromium complexes are slightly distorted, whereas those of manganese are severely distorted.     

Transition metal chemistry of oxime-containing ligands,IX

The vibrational (conventional and far-infrared) and diffuse-reflectance spectra in conjunction with magnetic susceptibility measurements over a temperature range down to liquid nitrogen temperature are reported and discussed for the complexes; [Mn(HPOX)₂ X ₂]; [Mn(HMPX)₂ X ₂]; [Fe(HPOX)(POX) X ₂] and [Fe(HMPX)(MPX) X ₂](whereHPOX=pyridine-2-aldoxime (C₆H₆N₂O);POX=C₆H₅N₂O;HMPX=6-Methylpyridine-2-aldoxime (C₇H₈N₂O);MPX=C₇H₇N₂O;X=Cl, Br, I, NO₃, NCS, or OA c andX ₂=SO₄). On the basis of these physical studies a six-coordinated structure is suggested for the manganese(II) and iron(III) complexes.Mössbauer spectra, measured at room-temperature and liquid nitrogen temperature also indicated a six-coordinate geometry for iron(III) complexes.

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Übergangsmetallkomplexe mit Oxim-enthaltenden Liganden, IX. Spektroskopische und magnetische Untersuchungen von Mn(II)- und Fe(II)-Komplexen mit Pyridin-2-aldoxim und 6-Methylpyridin-2-aldoxim

Zusammenfassung Es wurden Komplexe von Pyridin-2-aldoxim (HPOX) und 6-Methylpyridin-2-aldoxim (HMPX) vom Typ [Mn(HPOX)₂ X ₂], [Mn(HMPX)₂ X ₂], [Fe(HPOX)(POX)X ₂] und [Fe(HMPX)(MPX)X ₂] (X=Cl, Br, I, NO₃, NCS, OA c;X ₂=SO₄) dargestellt. Die Diskussion erfolgt basierend auf Infrarot-spektroskopie (inklusive fernes IR), Messungen der magnetischen Suszeptibilität (Temp. bis zu fl. N₂) undMössbauer-Spektroskopie.

     

Complexes of metal ions with phosphorus or arsenic containing ligands,part XX. Chelates ofo-phenylenebis(diarylarsines) with palladium(II) and platinum(II) halides,pseudohalides and perchlorates

Summary Two ditertiaryarsines,o-phenylenebis(diphenylarsine), (pdpa) ando-phenylenebis(di-p-tolylarsine), (pdta) yield some new complexes of palladium(II) and platinum(II). These are: square planar M(pdta)X₂ · nCH₂Cl₂, [M = Pd, X = Cl, Br or NCS; M = Pt, X = Cl]; [Pt(A-A)₂] X₂ · nCH₂Cl₂, [(A-A) = pdta, X = Cl, NCS or ClO₄; (A-A) = pdpa, X=ClO₄] and [M₂(A-A)₂(NCS)₂] (ClO₄)₂ · nCH₂Cl₂, [M = Pd, (A-A) = pdta; M = Pt, (A-A) = pdpa]; distorted octahedral M(pdta)₂-X₂nCH₂Cl₂, [M = Pd, X = I; M = Pt, X = Br or I] and [Pd(pdta)₂(H₂O)₂](ClO₄)₂, and five coordinate [M(A-A)₂X] ClO₄ · nCH₂Cl₂, [M = Pd, Pt, (A-A) = pdta, X = I; M = Pt, (A-A) = pdpa, X = Br or I]. The [M₂(A-A)₂(NCS)₂] (ClO₄)₂ · nCH₂Cl₂ complexes are novel in the sense that they contain bridging thiocyanate together with ionic perchlorate. The stereochemical assignments have been made on the basis of i.r. and u.v. spectra as well as conductance data.     

Synthesis and Thermal Studies of 2,4'-bipyridyl Complexes of Manganese(II) Salts

2,4'-Bipyridyl (2,4'-bipy or L) complexes of Mn(II) with the formulae MnL₂X₂·2H₂O (X_–=Cl, Br, NCS, NO₃), MnLSO₄·5H₂O and MnL₄(ClO₄)₂·2H₂O were synthesized and characterized via the IR spectra and magnetic, and conductivity measurements. The nature of the Mn(II)-ligand coordination is discussed. The thermal decompositions of these compounds were studied in air atmosphere. The mode of decomposition depends on the anion present, but the final product in all cases is Mn₃O₄. Some of the intermediates (MnL₂Cl₂, MnLCl₂, MnL₂Br₂, MnL₂(NCS)₂ and MnLSO₄) formed during the pyrolysis are isomeric with 2,2'-bipy and 4,4'-bipy complexes.This revised version was published online in November 2005 with corrections to the Cover Date.     

Co-ordination compounds of diacetyldihydrazone and diacetylbis(monomethylhydrazone)

Summary Diacetyldihydrazone (DADH) forms only six-coordinate complexes with iron(II), cobalt(II), nickel(II) and zinc(II). In M(DADH)₂X₂ (M=Fe, X=Br or I; M=Co, X=I; M=Ni, X=Cl, Br or NCS) the ligand is chelating in the [M(DADH)₃]²⁺ cations, while in M(DADH)₂X₂ (M=Co, X=Cl or Br; M=Ni, X=Cl or Br) the ligand is probably bridging and bidentate. Diacetylbismonomethylhydrazone (DAMH), by contrast, forms predominantly tetrahedral complexes M(DAMH)X₂ (M=Fe or Co, X=Cl or Br; M=Ni, X=Br; M=Co, X=NCS; M=Zn, X=Cl, Br or NCS) and some octahedral complexes M(DAMH)₂X₂ (M=Co, X=NCS; M=Ni, X=Br). The i.r. spectra, electronic spectra and magnetic moments of the complexes are discussed.     

Copper(II) complexes of 2-amino-1,3,4-thiadiazole and 2-ethylamino-1,3,4-thiadiazole

Summary Some copper(II) complexes of 2-amino-1,3,4-thiadiazole (atz) and 2-ethylamino-1,3,4-thiadiazole (eatz) have been prepared and studied by electronic, i.r. and e.p.r. spectra and by magnetochemical and conductometric methods. The CuX₂ · atz (X=Cl, Br) and CuCl₂ · eatz complexes are presumably six-coordinate with bridging ligand molecules and asymmetrically bridging halide ions, while the CuX₂ · 2 atz (X=Cl, Br) complexes probably have a flattened tetrahedral N₂X₂ moiety with apical interactions. The CuBr₂ · 5/3 eatz · 2/3 MeOH and Cu(OAc)₂ · L (L=atz or eatz) complexes have subnormal magnetic moments (1.53-1.40 B.M.). The acetato-complexes have a dimeric structure with bridging acetato-groups, copper-copper interactions and apical ligand molecules. The ligands bond principally through the amine nitrogen atom and, when bridging, also through one ring-nitrogen.     

Coordination compounds of hydrazine derivatives with transition metals,XXIII cobalt(II) chelates of bis(N-salicylidene)dicarboxylic acid dihydrazides

The reaction of bis(N-salicylidene)dicarboxylic acid dihydrazides (H₄ Lig) with cobalt(II) salts was investigated. Chelates of the types Co(H₃ Lig)X ·nH₂O, Co₂(H₂ Lig)X ₂, Co₃(H₃ Lig)₂ X ₄, Co(H₂ Lig) ·nH₂O and Co(H₃ Lig)₂ ·nH₂O (X=Cl, Br, I or SCN) were isolated and characterized by their infrared and electronic spectra as well as their magnetic properties.

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Koordinationsverbindungen von Hydrazinderivaten mit Übergangsmetallen, 23. Mitt.: Kobalt(II)-Chelate von Bis(N-salicyliden)dicarbonsäuredihydraziden

Zusammenfassung Die Reaktion von Bis(N-salicyliden)dicarbonsäuredihydraziden (H₄ Lig) mit Kobalt(II)-Salzen ergab Chelate vom Typ Co(H₃ Lig)X ·nH₂O, Co₂(H₂ Lig)X ₂, Co₃(H₃ Lig)₂ X ₄, Co(H₂ Lig) ·nH₂O and Co(H₃ Lig)₂ ·nH₂O (X=Cl, Br, I oder SCN). Die Charakterisierung erfolgte mittels IR, Elektronenspektren und magnetischer Eigenschaften.

     

Cobalt(II), nickel(II), copper(II) and copper(I) complexes of 2-mercapto-5-methyl-1,3,4-thiadiazole and 2,5-bis(methylmercapto)-1,3,4-thiadiazole

Summary Some cobalt(II), nickel(II), copper(II) and copper(I) complexes of 2-mercapto-5-methyl-1,3,4-thiadiazole (mttz) and 2,5-bis(methylmercapto)-1,3,4-thiadiazole (bmttz) have been prepared and studied by conductometric and magnetochemical methods and by electronic and i. r. spectroscopy. The complexes CoX₂ · 2L (L=mttz, X=Cl, Br or I; L=bmttz, X=Br or I), CoCl₂ · bmttz are pseudotetrahedral, and the complexes NiX₂ · mttz (X=Cl or Br), NiCl₂ · 1.3 bmttz, NiBr₂ · 1.5 bmttz are pseudooctahedral. The complex Co₃(OAc)₂ · 4(mttz-H) · 2H₂O has an undefinite constitution. The polynuclear complexes CuCl₂ · 1.3 mttz and CuBr₂ · 1.2 mttz contain presumably pseudotetrahedral chromophores, the chloride having a subnormal magnetic moment. The CuX₂ · 2 bmttz (X=Cl, Br or NO₃) complexes have a six coordination with bridging ligand molecules. In the CuX · 2 mttz (X=Cl, Br or ClO₄) complexes the anions are coordinated, while in the CuClO₄ · 2 bmttz complex the perchlorate anion is ionically bonded.     

Synthesis and spectroscopic, diffractometric, and magnetic analysis of lanthanide compounds with thiocyanate and hexamethylenetetramine

Summary New complex salts of lanthanide thiocyanates with hexamethylenetetramine of the general formulaLn(NCS)₃·2[N₄(CH₂)₆·nH₂O, whereLn=La,Pr,Nd,Sm,Gd,Dy,Er andn=0–10, have been analyzed. IR spectra have been obtained in the range of 200–4000 cm^–1, frequencies of vibrations of low and high hydration state compounds have been analyzed, and differences between the structures of the coordination speheres of these salts are demonstrated. Diffractometric examinations and measurements of the magnetic susceptibility of several salts have been performed.

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Synthese und spektroskopische, diffraktometrische und magnetische Untersuchungen von Verbindungen der Lanthaniden mit Rhodanid und Hexamethylentetramin

Zusammenfassung Neue Komplexsalze der Lanthaniden mit Rhodanid und Hexamethylentetramin mit der allgemeinen FormelLn(NCS)₃·2[N₄(CH₂)₆]·nH₂O (Ln=La,Pr,Nd,Sm,Gd,Dy,Er;n=0–10) wurden untersucht. Die IR-Spektren der Verbindungen im Bereich von 200–4000 cm^–1 wurden aufgenommen. Die Schwingungsfrequenzen hoch- und niederhydrierter Verbindungen wurden analysiert und die Unterschiede in der Struktur der Koordinationssphäre bestimmt. An einigen Komplexen wurden diffraktometrische Untersuchungen und Messungen der magnetischen Suzaptibilität durchgeführt.

     

Neue stellungsisomere reineckesalzähnliche Verbindungen mit Toluidinen

Zusammenfassung Es wurden eine Reihe von Substitutionsreaktionen mit entwässertem K₃[Cr(NCS)₆] und aromatischen Aminen, ohne Verwendung von Lösungsmitteln, durchgeführt. Es wurde beobachtet, da die sehr schwachen Basen mit p_K-Werten 14–16, wie die isomeren Mono- und Dinitro-aniline, die Anthranil- und Sulfanilsäuren, für diese Substitutionsreaktionen ungeeignet sind. Die Alkyl-anilinderivate, wie daso-, m- undp-Toluidin (p_K=10–11) bilden dagegen leicht reineckesalzähnliche Verbindungen: Amin· H[Cr(Toluidin)₂(NCS)₄]. Die Zusammensetzung der neuen Komplexanionen wurde bei einer Reihe von doppelten Umsetzungsreaktionen mit den Chlorhydraten einiger heterocyclischen Aminen festgestellt.Für die Klärung einiger Strukturfragen wurden spektrophotometrische Untersuchungen im UV und IR durchgeführt und die thermische Stabilität bzw. der Mechanismus des Pyrolysenvorganges auf thermogravimetrischem Wege verfolgt.

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Substitution reactions of anhydrous K₃[Cr(NCS)₆] with aromatic amines without applying of solvents were studied.It was observed, that the very weak bases (pK-values 14–16, e.g. isomeric mono- and dinitro-anilines, the anthranilic and sulfanilic acids) are unsuitable for substitution reactions. The alkylaniline derivates e.g.o-, m- andp-toluidine (pK=10–11) form easily reineckesalt analogous compounds: Amin· ·H[Cr(toluidine)₂(NCS)₄]·The formula of the 3 new complex anions: [Cr(toluidine)₂ (NCS)₄]- was established by preparative methods, with a series of double decomposition reactions, using chlorohydrates of some heterocyclic amines for this purpose. From spectroscopical investigations (UV and IR) some structural problems are resolved and discussed.The thermal stability and the mechanism of pyrolysis of these salts was studied by thermogravimetric analysis.

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Mit 8 Abbildungen     

Neue Isocyanato- und Isothiocyanatoderivate des Siliciums

The preparation of the new silanes HSi(NCO)₃ and HSi(NCS)₃ from trihalosilanes and silver halogenoides is described. Based on vibrational and nmr spectroscopic arguments the inductive effect of the NCO- and NCS-groups is discussed. The mixed compounds HSiX ₂(NCO) (X=Cl, Br, I), HSiX(NCO)₂ (X=Cl, Br, I), H₂SiCl(NCO), HSiX ₂(NCS) (X=Cl, Br) and HSiCl(NCS)₂ are prepared by halogen/halogenoid exchange reactions and are characterized spectroscopically.