Neue Reineckesalzanaloge Verbindungen mit tertiären aromatischen Aminen

Substitution reactions of anhydrous K₃[Cr(NCS)₆] with tertiary aromatic monoamines such as N,N-dimethylaniline and N,N-diethylaniline were carried out in the absence of solvents. The tertiary amines readily form compounds analogous to Reinecke salts,amine ₂H[Cr(NCS)₄(N,N-dimethylaniline)₂] andamine ₂H[Cr(NCS)₄(N,N-Diethylaniline)₂] respectively. The formula of the new complex anions was established by a series of double decomposition reactions with the hydrochlorides of some heterocyclic N-bases, alcaloids and cobalt(III)-ammine complexes. Some structural problems were resolved by UV and IR spectroscopic studies.     

Neue Tetrathiocyanato-diamin-Chromiate mit aliphatischen Monoaminen

New Tetrathiocyanato-diamine-chromiates with Aliphatic Monoamines Two new Reinecke salt like compounds were obtained by a substitution reaction of anhydrous K₃[Cr(NCS)₆] with aliphatic monoamines (n-propylamine and n-butylamine) in the molten state. The formulae of the [Cr(CNS)₄(n-propylamine)₂]^? and [Cr(NCS)₄(n-butylamine)₂]^? were proved by a series of double decomposition reactions with the hydrochlorides of heterocyclic N-bases and alkaloids and with cobalt(III)-amine bases, respectively. From spectroscopical investigations (u.v. and i.r.) some structural problems are resolved and discussed.     

Thermal studies on the decomposition of aquopentamminecobalt(III) hexathiocyanatochromate(III)

The decomposition of [Co(NH₃)₅H₂O] [Cr(NCS)₆] has been studied using DSC and TG. The first step involves the loss of H₂O and NH₃ in a first-order process to produce [(NH₃)₅Co(SCN)₃Cr(NCS)₃]. A second step involves the loss of HSCN. Activation energies are presented and the mechanisms of the reactions are discussed in comparison to analogous cyanide complexes.     

Kinetic analysis of thermogravimetric data. XXIII. Thermal decomposition of some [Co(pyridine)4(NCX)2] type complexes

A derivatographic study of the thermal decomposition of [Co(py)₄(NCX)₂] type complexes (X = O, S, Se) shows the first two decomposition stages to be the release of the four pyridine molecules. Co(NCS)₂ is a relatively stable intermediate, but the others immediately undergo the further decomposition reactions: Co(NCO)₂ → Co(CN)₂ → Co₃O₄ and Co(NCSe)₂ → Co₂(SeO₃)₃ → Co₃O₄, respectively. Even the Co(NCS)₂ is oxidized at higher temperatures, presumably giving a mixture of sulphate and oxide. From the TG curves kinetic parameters are derived for the deamination reactions. These parameters depend on the working conditions. A kinetic compensation effect is observed and discussed.     

Kinetic analysis of thermogravimetric data. XVIII. Thermal decomposition of some [Co(AMINE)2 (NCS)2] type complexes

[Co(p-toluidine)₂(NCS)₂] (I), [Co(m-toluidine)₂(NCS)₂] (II) and [Co(aniline)₂(NCS)₂] (III) have been synthesized. Kinetic parameters n, E and Z (apparent reaction order, activation energy and pre-exponential factor) have been derived from the TG curves recorded under 12 different working conditions. The influence of the sample weight (m_o) and of the heating rate (q) upon the kinetic parameters as well as upon the decomposition temperature and the amount of amine liberated in the first decomposition stage are discussed. Mean values of the activation energy and of the decomposition temperature are discussed in terms of the Co—amine bond strength and molecular structure based on IR evidence.     

Kinetic analysis of the decomposition of piperidinium hexathiocyanoatochromate(III)

Summary The decomposition of piperidinium hexathiocyanatochromate(III), (pipH)₃[Cr(NCS)₆](s), into Cr(NCS)₃(s) and pipHSCN(g) has been studied isothermally and nonisothermally using t.g.a. Data from isothermal studies were analysed according to 17 different kinetic models and the (, T) data from nonisothermal experiments were analysed using 12 rate laws by the procedure of Reich and Stivala. It was found that while a first-order rate law gave the best fit to the data obtained from isothermal and nonisothermal experiments most frequently, considerable variation exists for both types of experiments. Using the first order model, the activation energy was found to be 77.2 ±4.4kJ mol^–1.     

Neue Substitutionsprodukte von K3[Cr(NCS)6] mit einigen heterocyclischen N-Basen

Substitution reactions of K₃[Cr(NCS)₆] with pyridine and alkyl-pyridine derivatives was studied. The formulas of three complex anions, [Cr(NCS)₄(pyridine)₂]^?, [Cr(NCS)₄(β-picoline)₂]^? and [Cr(NCS)₄(γ-picoline)₂]^?, was established by preparation. 33 new complex compounds of these types have been prepared from the hydrochlorides of aromatic and heterocyclic amines. Their thermal behaviour and the mechanism of pyrolysis of these salts was studied by TGA. From UV and IR spectra some structural problems are resolved and discussed.     

Neue Substitutions-Verbindungen des K3[Cr(NCS)6] mit tertiären Phosphinen

New Substitution Compounds of K₃[Cr(NCS)₆] with Tertiary Phosphines . New substitution reactions of K₃[Cr(NCS)₆] with mixed tertiary phophines in n-butanol were carried out. The formulae of the new anions: [Cr(NCS)₄(diethyl-phenylphosphine)₂]^? and [Cr(NCS)₄(diethyl-p-tolyl-phosphine)₂]^? were established by preparation of 30 new derivatives with the hydrochlorides of some organic N-bases, metals, and metal(III) ammines. Electronic and i.r. spectral data are communicated.     

Time-resolved fluorescence spectra using time-correlated photon counting: Picosecond fluorescence in aqueous solutions of Cr(III) complexes at room temperature

A new procedure for measuring time-resolved emission spectra has been implemented. This technique has subnanosecond time resolution combined with the sensitivity and dynamic range needed to cope with extremely weak luminescence. Using this method the emissions of Cr(NH₃)₂ (NCS)₄^? and Cr(NCS)₆^3- in aqueous solution at room temperature have each been analyzed into two components. The fast component has a broad spectrum and is assigned to prompt fluorescence with lifetime below 100 ps. The slow component is dominated by phosphorescence but may include some delayed fluorescence. The phosphorescence lifetime is 5.5 ± 0.5 ns in Cr(NH₃)₂ (NCS)₄^? and 1.65 ± 0.1 ns in Cr(NCS)₆^3-. Order of magnitude estimates have been derived for other photophysical parameters.     

Heterogeneous reactions of solid nickel(II) complexes XXIV

The Stoichiometry of thermal decomposition was studied for the following compounds: Ni(NCS)₂(pip)₄ (I), (pip=piperidine), Ni(NCS)₂(pip)₂py·H₂O (II), (py=piridine), Ni(NCS)₂(4-Mepip)₃ (III), Ni(NCS)₂(3-Mepip)₃ (IV) and Ni(NCS)₂(3.5-Me₂pip)₃ (V). In complexes I, II, III and IV the loss of the volatile ligands (on the TG curve to 300 °C) occurs in three steps and in complex V in two steps. The loss of the last molecules of volatile ligands is accompanied by the decomposition of NCS groups. Spectral data and magnetic moment values for the initial complexes I and II (together with the defined intermediates) indicated pseudooctahedral configuration while pentacoordination for complexes III, IV and V. Structural changes of the complexes studied in thermal decomposition reactions are discussed.     

Kobalt(III)ammin-derivate einiger Reineckesalz-Analoga mit Xylidinen

Zusammenfassung Es wurden 34 neue Komplexsalze durch doppelte Umsetzung aus wäßr.-alkohol. Lösungen der folgenden Reineckeat-Analoga: [Cr(NCS)₄(m-xylidin)₂]^–, [Cr(NCS)₄(p-xyl)₂]^– und Hexammin-, Monoacido-pentammin- und Diacido-tetramminkobalt(III)-komplexsalze erhalten. Es wurden in einigen Fällen Unterschiede in physiko-chemischen Eigenschaften, wie Farbtönung, Kristallform, Löslichkeit und papierchromatographischeR _f-Werte, bei den stellungsisomeren Salzen vom Typus: Kation · [Cr(NCS)₄(xyl)₂] und auch bei den Koordinationsisomerpaaren: [Co(DH)₂(m-xyl)₂] [Cr(NCS)₄(p-xyl)₂] und [Co(DH)₂(p-xyl)₂] [Cr(NCS)₄(m-xyl)₂] usw. beobachtet.

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Cobalt(III)ammine derivatives of some reineckate analogues with xylidines

34 new complex salts were prepared by double conversion of the reineckate analogues [Cr(NCS)₄(m-xylidine)₂]^–, [Cr(NCS)₄(p-xyl)₂]^–, with the hexammine-, monoacido-pentammine- and diacidotetrammine-complexes of Co(III). In some of the position and coordination isomeres differences of the standard physico-chemical properties, i.e. color, crystal form, solubility and paper chromatographyR _f-values were observed.

     

Study of a Mn–Cr/TiO2 mixed oxide nanocatalyst prepared via an inorganic precursor complex for high-temperature water–gas shift reaction

The influence of three preparation methods on the properties and reaction performances of a titania-supported Mn–Cr bimetallic nanocatalyst for high-temperature water–gas shift reaction has been studied. Impregnation, co-precipitation and thermal decomposition of the [Mn(H₂O)₆]₃[Cr(NCS)₆]₂·H₂O/TiO₂ precursor as an inorganic precursor complex were utilized for the preparation of the Mn–Cr/TiO₂ catalysts. The calcined catalyst and the precursor that were used for its preparation were characterized by powder X-ray diffraction, scanning electron microscopy, Brunauer–Emmett–Teller specific surface area measurements, thermal gravimetric analysis, differential scanning calorimetry and Fourier transform–infrared spectroscopy. The high-temperature water–gas shift activity was appraised in the temperature range from 280 to 420 °C. The results showed that thermal decomposition of inorganic precursor complexes is more advantageous than impregnation and co-precipitation methods for the preparation of Mn–Cr/TiO₂ catalysts for high-temperature water–gas shift reaction.     

Kobalt(III) ammin-derivate einiger Reineckesalz-Analoga mit Toluidinen

Zusammenfassung Es wurden 39 neue Komplexsalze durch doppelte Umsetzung aus wäßrig-alkohol. Lösungen der folgenden Reineckeat-Analoga: [Cr(NCS)₄(o-Toluidin)₂]^–, [Cr(NCS)₄(m-Toluidin)₂]^– und [Cr(NCS)₄(p-Toluidin)₂]^– und Hexammin-, Monoacido-pentammin-und Diacido-tetrammin-kobalt(III)-komplexsalze erhalten.Es wurden in einigen Fällen Abweichungen in physikochemischen Eigenschaften, wie Farbtönung, Kristallform, Löslichkeit und papierchromatographischeR _F-Werte, bei den stellungsisomeren Salzen vom Typus: Kation·[Cr(NCS)₄(Toluidin)₂] und auch bei den Koordinationsisomerpaaren: [Co(DH)₂(o-Toluidin)₂][Cr(NCS)₄(p-Toluidin)₂] und [Co(DH)₂(p-Toluidin)₂] [Cr(NCS)₄(o-Toluidin)₂], usw. beobachtet.

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Cobalt(III) ammine derivatives of some reineckate analogues with toluidines

39 new complex salts were prepared by double conversion of the reineckate analogues [Cr(SCN)₄(o-toluidine)₂]^–, [Cr(SCN)₄(m-toluidine)₂]^–, and [Cr(SCN)₄(p-toluidine)₂]^– with the hexammine, monoacido-pentammine and diacido-tetrammine complexes of Co(III). In some of the position and coordination isomers deviations from the standard physico-chemical properties, i.e. color, crystal form, solubility and paper chromatographyR _f-values were observed.

     

Synthesis and physicochemical properties of [{Cd(?-C6H11NO)5}2Cr(NCS)6][Cd(?-C6H11NO)4Cr(NCS)6]

A new complex [{Cd(?-Cpl)₅}₂Cr(NCS)₆][Cd(?-Cpl)₄Cr(NCS)₆] was synthesized, and its crystal structure was solved. The complex was studied by chemical analysis and IR spectroscopy.     

Neue stellungsisomere Reineckesalzanaloga mit Meta- und Para-Toluylendiamin

New Position Isomeric Analoga of Reinecke Salt with m- and p-Tolylenediamine Two position isomeric Reinecke salt analogous complexes, [Cr(NCS)₄(m-TolyIenediamine)₂]^? and [Cr(NCS)₄(p-Tolylenediamine)₂]^?, were obtained by means of substitution reactions of anhydrous K₃[Cr(NCS)₆] with meta and para tolylenediamine, respectively, without solvent. The formulae of the new complex anions were established by preparation of 18 new derivatives with the hydrochlorides of some alksloides, and cobalt(III) amine bases. From electronic and IR spectral data some structural problems are solved. The thermal stability of some complexes was discussed on the basis of derivatographic analysis.     

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     

Heterogeneous reactions of solid nickel(II) complexes,VI

The kinetics of the thermal decomposition of square-planar complexes of the type Ni(NCS)₂L₂ (L=α-picoline; 2,6-lutidine and quinoline) was studied by following the loss of weight and using the isothermal method, in the temperature range of 72–147°. The reaction order found wasn=2/3; this together with macroscopic observations indicates that it is the proper chemical process which is the controlling factor of the total decomposition rate. The values of the activation energies decrease in the following order: Ni(NCS)₂ Q₂ > Ni(NCS)₂(2,6-lut)₂ > Ni(NCS)₂(α-pic)₂; this points to the reaction course according to the associative activation. Except for Ni(NCS)₂Q₂,ΔH was found to be >E _a. This experimental result may be explained by a multi-step mechanism. Possible intermediates are discussed.     

Darstellung,Isolierung und Charakterisierung Gemischter Cyanothiocyanatoäthylendiamin-Chrom(III)-Komplexe

Preparation, Isolation and Characterisation of Mixed Cyanothiocyanato-ethylenediamine-Chromium(III) Complexes The complex salts K[Cr(CN)(NCS)₃(en)] and [Cr(CN)(NCS)(en)₂]SCN are prepared for the first time. After the preparative isolation by column chromatography on alumima, they are characterized by the chromium content and the spectra.     

The first heterometallic Cu(II)/Cr(III) complex with an open-chain Schiff-base ligand self-assembled from copper powder,Reineckes salt,ethylendiamine and acetone

A novel supramolecular assembly [{Cu(enac)}₂Cr(NCS)₄(NH₃)₂][Cr(NCS)₄(NH₃)₂]₃ · 4(CH₃)₂CO (enac = 4,6,6-trimethyl-3,7-diazanon-3-ene-1,9-diamine), the first example of a Cu/Cr heterometallic compound containing a Schiff-base ligand such as enac, and an anion of Reineckes salt, Cr(NCS)₄(NH₃)₂⁻, as a building block, was obtained by the self-assembly reaction of copper powder and Reineckes salt in an acetone/methanol (1:4) solution of ethylenediamine in the open air. An X-ray study shows that the complex includes a trinuclear Cu₂Cr cation, constructed from two Cu(enac)²⁺ moieties and a trans-[Cr(NCS)₄(NH₃)₂]⁻ block as a two-linking bridging ligand. The metal–metal separations within the cation are Cu?Cr = 6.393(31) Å and Cu?Cu = 12.786(63) Å. The supramolecular architecture of the complex involves two types of H-bonded chains, the first chain is generated by trinuclear cations [{Cu(enac)}₂Cr(NCS)₄(NH₃)₂]²⁺, [Cr(NCS)₄(NH₃)₂]⁻ anions and (CH₃)₂CO molecules, while the second by crystallographically different anions of Reineckes salt and (CH₃)₂CO. Variable-temperature (1.8–300 K) magnetic susceptibilities show a slight change of the μ_B value at low temperature, indicative of weak antiferromagnetic interactions (J_CuCr = −0.9 cm⁻¹) between the paramagnetic centers.     

Heterogene Reactionen fester Nickel(II)-Komplexe. XXI. Thermische Zersetzung und Stereochemie der Thiocyanato-Nickel(II)-Komplexe mit Pyridin-N-Oxid und Methylsubstituierten Pyridin-N-Oxiden

Heterogeneous Reactions of Solid Nickel(II) Complexes. XXI. Thermal Decomposition and Sterochemistry of Thiocyanato-Nickel(II) Complexes with Pyridine N-Oxide and Methylsubstituted Pyridine N-Oxides The thermal decomposition was studied for the complexes: Ni(NCS)₂(pyNO)₃ · H₂O (I), (pyNO = pyridine N-oxide), Ni(NCS)₂(2-MepyNO)₃ (II) Me = Methyl, Ni(NCS)₂(3-MepyNO)₂ · C₂H₅OH (III) and Ni(NCS)₂(4-MepyNO)₂ · H₂O (IV). On heating the solvent molecules bonded escape and then the decomposition of heterocyclic ligands sets in. The spectral and magnetic data indicate a pseudooctahedral configuration of the starting complexes as also of Ni(NCS)₂(pyNO)₃ (V), Ni(NCS)₂(3-MepyNO)₂ (VI) and Ni(NCS)₂(4-MepyNO)₂ (VII), i. e. of the initial complexes without the solvent molecules. For complexes of the type of [Ni(NCS)₂L₃] · xH₂O (L = pyNO, x = 0, 1; L = 2-MepyNO and x = 0) a dimeric structure is assumed, while for those of the type of [Ni(NCS)₂L₂] · xH₂O (C₂H₅OH) (L = 3-MepyNO and 4-MepyNO, x = 0 or 1) a polymeric structure is supposed.