Über Reaktionen oxygenierter Kobalt(II)-Komplexe. IX. Oxydative Eigenschaften von Tetrakis(äthylendiamin)-μ-peroxo-μ-hydroxo-dikobalt(III)

Reactions of oxygenated cobalt(II) complexes. IX. Oxidative properties of tetrakis(ethylenediamine)-μ-peroxo-μ-hydroxo-dicobalt(III)

1 VIII s. [1].

[(en)₂Co(O₂, OH)Co(en)₂]³⁺ ( a ) reacts with I^? in acidic aqueous solution according to: Co^III(O₂, OH)Co^III + 21^? + 5H⁺ ? 2Co^III + 3H₂O + I₂. Using I^? in excess first order rate constants are obtained which, to a first approximation, are independent of [I^?]. Comparison with kinetic data of deoxygenation of [(en)₂Co(O₂, OH)Co(en)₂]³⁺ under analogous conditions suggests that both reactions have the same rate determining step. The singly bridged species [(en)₂(H₂O)CoO₂Co(H₂O) (en)₂]⁴⁺ is shown to be the reactive intermediate in the iodide oxidation (Schema 2).     

Mehrkernige Kobaltkomplexe. V. Präparative Herstellung von Tetrakis (äthylendiamin)-μ-peroxo-μ-amido- und μ-peroxo-μ-thiocyanatodikobalt (III)-Komplexen ausgehend von Tetrakis (äthylendiamin)bis-(ammin)-μ-peroxo-dikobalt (III)-tetraperchlorat

Polynuclear Cobalt Complexes. V. Preparation of tetrakis (ethylenediamine)-μ-peroxo-μ-amido and μ-peroxo-μ-thiocyanato-dicobalt (III) complexes starting from tetrakis (ethylenediamine)bis-(ammine)-μ-peroxo-dicobalt (III)-tetraperchlorate Racemic tetrakis (ethylenediamine)-μ-peroxo-μ-amido-dicobalt (III) thiocyanate and its corresponding hydroperoxo- and superoxo-complexes have been isolated from [(en)₂(NH₃)Co(O₂)(NH₃)(en)₂](ClO₄)₄. A new binuclear peroxo complex containing thiocyanate as bridging ligand was prepared by the same method. The stretching frequencies of the CN- and CS-group as well as the NCS-bending frequence in the IR. spectrum of [(en)₂Co(O₂, SCN)Co(en)₂](NO₃)₃ suggest that the μ-thiocyanato group is N-bonded (2050, 750, 475 cm^?1). A comparison of IR. spectra of known singly and doubly bridged μ-peroxo complexes is made. Characteristic absorption bands, assignable to ν(O? O) and ν(Co? O) are given.     

Über Reaktionen oxygenierter Kobalt(II)-Chelate. II. Konfigurationsisomere Oxygenierungsprodukte von Tetraäthylenpentaminkobalt(II)

On oxygenation of alcoholic solutions of tetraethylenepentamine cobalt(II) two isomeric forms of [(tetren)CoO₂Co(tetren)]⁴⁺ are obtained in which the configuration of the pentadentate ligand is either α or β. The binuclear complex can be crystallized as thiocyanate or as perchlorate. Oxygenation at 35° produces the pure α isomer. At lower temperature a mixture of α and β is obtained. The isomers differ slightly in their absorption spectra and their reactivity. The ligand configuration has been elucidated by transforming the perchlorates into the [ZnCl₄]^2? salts of the corresponding mononuclear chelates [Co(tetren)Cl]²⁺. The latter have also been prepared starting from a compound of known configuration according to the literature. The IR. spectra of the α and β forms differ characteristically in the NH stretch bands.     

Präparative Darstellung von μ-Disauerstoff-bis-kobalt(II)-Chelaten

Binuclear cobalt chelates with O₂ as bridging ligand have been prepared, using ethylenediamine, triethylenetetramine, tetraethylenepentamine and tris-(2-aminoethyl)-amine as chelating agents and SCN^? and ClO₄^? as anions. They form well characterized crystals which give off molecular oxygen spontaneously in acid solution and, except in the case of the cobalt tetra-ethylenepentamine chelate, reveal the general composition [(Z)Co · μ(O₂, OH) · Co(Z)]X₃, where Z represents the polydentate complexing agents and X the anion. In the presence of ammonia different complexes are produced, in which NH₃ occupies one coordination site of each cobalt, replacing the hydroxo bridge.     

Über Reaktionen oxygenierter Kobalt(II)-Chelate. VII. Zur Stabilität einfach und doppelt verbrückter μ-Peroxo-dikobalt(III)-Komplexe

On reactions of oxygenated Cobalt(II) Chelates. VII. Stability of mono and doubly bridged μ-Peroxo-dicobalt(III) Complexes. The oxygen carrier properties of the cobalt(II) chelates of symmetrical diethylenetriamine-4-acetic acid (dtma) and unsymmetrical ethylenediamine-1,1-diacetic acid (edda) have been investigated by O₂ equilibrium measurements in alkaline solution. Maximum O₂ uptake is at pH = pK_H (4), indicating that μ-peroxo-μ-hydroxodicobalt(III) ion is the only oxygenated species formed in aqueous solution. Relationships between stability and structural factors are discussed.     

Über Reaktionen oxygenierter Kobalt (II)-Chelate. Zur Stereochemie binuclearer Oxygenierungsprodukte von Triäthylentetraminkobalt (II)

⁵⁹Co- and ¹H-NMR. spectra as well as preparative work have shown that oxygenation of solutions of triethylenetetramine cobalt(II) leads to a mixture of isomeric forms of [Co₂(trien)₂μ (O₂, OH)]³⁺. Using a new preparative method, starting from mononuclear cobalt(III)-chelates, a binuclear μ-peroxo-cobalt(III) complex has been obtained in two different forms, where the chelate configuration is predominantly either α-cis or β-cis in both centres. The two configurations can be distinguished by IR. spectroscopy.     

Über Reaktionen oxygenierter Kobalt(II)-Komplexe. V. Reaktivität diastereoisomerer μ-Peroxo-μ-hydroxo-dikobalt(III)-Ionen

On Reactions of oxygenated Cobalt(II) Complexes. V. Reactivity of diastereoisomeric μ-peroxo-μ-hydroxo-dicobalt(III) Ions The kinetics of dissociation of μ-peroxo-μ-hydroxo-dicobalt(III) chelates have been reinvestigated using a stopped flow technique. The binuclear cations [(trien)Co(O₂, OH) Co(trien)]³⁺, [(tren)Co(O₂, OH)Co(tren)]³⁺ and [(en)₂Co(O₂, OH)Co(en)₂]³⁺ dissociate on acidifying to Co²⁺ and the protonated ligand and up to 100% of the bound O₂ is evolved. The dissociation is H⁺-catalyzed and first order in complex. The observed rate constants at pH 2 are in the range of 10^?3 to 10^?1 s^?1 (20°). They depend not only on the nature of the ligand and on ligand configuration but also on the diastereoisomeric structure of the binuclear cation. In the case of trien there are 8 possible chemically different isomers. On oxygenation of Co(trien)²⁺ in dilute solution 3 of those isomers seem to be formed preferentially. Their rate constants are separated over a factor of 50. For [(en)₂ Co(O₂, OH)Co(en)₂]³⁺ there exist a meso form and a chiral structure. On oxygenation of Co(en)₂²⁺ in dilute solution the meso form and the racemate are formed to about equal amounts. The racemate dissociates about 5 times slower. Of the 3 possible achiral isomers of [(tren)Co(O₂, OH)Co(tren)]³⁺ one is formed stereoselectively by oxygenation in solution.     

Zur Kenntnis von Dinitrito-kobalt(III)-Komplexen. I Darstellung und Absorptions-Spektren der Dinitrito-di(äthylendiamin)-kobalt(III)-perchlorate

On Dinitrito Cobalt(III) Complexes. I. Preparation and Absorption Spectra of Di(ethylenediamine) Cobalt(III) Perchlorates Cis and trans dinitrito diethylenediamine cobalt perchlorates could be prepared starting with carbonato and trans dichloro ethylenediamine cobalt perchlorate. Spectroscopic data are reported and compared with those of the corresponding dinitro complexes.     

Reaktion oxygenierter Kobalt (II)-Komplexe. XII. Über einen binuclearen μ-Peroxodikobalt (III)-Komplex mit makrocyclischem Brückenring

Reactions of oxygenated cobalt(II) complexes. XII. A binuclear μ-peroxodicobalt(III) complex with a macrocyclic bridging ring

1 XI: siehe [1].

Singly bridged [(tren) (NH₃) CoO₂(NH₃) (tren)]⁴⁺ reacts with excess tren by replacement of NH₃ in cis-position to the peroxo group and formation of a new type of doubly bridged μ-peroxo complex. An X-ray structure determination of [(tren)-Co(O₂, tren)Co(tren)] (ClO₄)₄ · 2 H₂O showed that the additional tren forms a macrocyclic bridging ring. The conformation of the CoOOCo group is transoid with a dihedral angle of 20°. The crystals are monoclinic with space group P2₁/c. The lattice constants are a = 9,798, b = 26,385, c = 16,385 Å, β = 110,2° with four formula units in the cell. The final R value is 0,124. ClO anions are disordered. The reactions of [(tren)Co(O₂, tren)Co(tren)]⁴⁺ in aqueous solution are compared with those of [(tren) (NH₃) CoO₂Co (NH₃tren)]⁴⁺. In acidic solution the new complex mainly decomposes to Co^II and O₂. In alcaline medium the bridging tren is replaced by an OH bridge, forming the well characterized doubly bridged [(tren)-Co(O₂, OH)Co(tren)]³⁺. Differing from the singly bridged bis (ammino) complex, the reactions of which show no pH dependency at all, the decomposition of the tren bridged complex is H⁺-catalyzed. The kinetic data have been interpreted as (i) preceding fast protonation step which is followed by a conformational change of the bridging ring, (ii) acid hydrolysis of a Co-μ-tren bond and (iii) fast cleavage of the Co-OO bond which is labilized by coordinated H₂O.     

Kobalt-Komplexe mit O2-Brücken: Die Struktur der Kationen μ-Hydroxo-μ-peroxo-bis[bis(äthylendiamin) kobalt(III)]3+ und μ-Hydroxo-μ-superoxo-bis[bis (äthylendiamin)kobalt(III)]4+

Cobalt Complexes with O₂ Bridges: The Structure of the Cations μ-Hydroxo-μ-peroxo-bis[bis(ethylenediamine) cobalt (III)]³⁺and μ-Hydroxo-μ-superoxo-bis [bis (ethylenediamine) cobalt (III)]⁴⁺ X-ray structure determinations of one salt of each of the two chemically and structurally closely related dinuclear cobalt cations [(en)₂Co · μ(OH, O₂) · Co(en)₂]³⁺ 1a and [(en)₂Co · μ(OH, O₂) · Co(en)₂]⁴⁺ 1b have been performed. In both cases the cations exist as racemic mixtures of ΔΔ and ΔΔ isomers. The O–O distance in the μ-peroxo cation 1a is 1.465 Å and the Co–O–O–Co torsion angle is 60.7°. The corresponding values for the μ-superoxo cation 1b are 1.339 Å and 22.0°.     

Über Reaktionen von Antimonhalogeniden. II. Die Reaktion von SbCl5 mit Oxalsäure-bis-(methylamid)

Reactions of Antimony Halides. II. The Reaction of SbCl₅ with Oxalic Acid Bis(methylamide) The reaction of antimony pentachloride with the dimethylamide of oxalic acid results in the formation of a five-ring heterocyclic compound C₄H₇Cl₄N₂O₂Sb(I), in which the ring components are Sb, N, C and O. It's synthesis and properties are discussed. Results of the mass spectrum see Table 1, a fraction scheme is given.     

Die Kristallstruktur von Bis(äthylendiamin)kupfer(II)-tris(brenzcatechino)silicat

The Crystal Structure of Bis(ethylenediamine)copper(II)-tris(pyrocatecholo) silicate From an equilibrium solution of silicic acid and pyrocatechol the violet, insoluble salt Cu(C₂H₈N₂)₂²⁺Si(C₆H₄O₂)₃^2? is precipitated by Cu(en)₂²⁺ ions. The triclinic crystal structure was determined. The distribution of the cations and anions resembles the BN type.     

Über die Darstellung von Di(i-propyl)thiosulfonium-Salzen

On the Preparation of Di(i-propyl)thiosulfonium Salts [1] The preparation of the mercaptosulfonium salts (i-C₃H₇)₂SSX⁺SbCl₆^? (X = H, D) and of the chlorothiosulfonium salts (i-C₃H₇)₂SSCl⁺MF₆^? (M = As, Sb) and (i-C₃H₇)₂SSSCl⁺SbCl₆^? is reported. They are formed by reaction of chlorinated or protonated (i-C₃H₇)₂S with excess H₂S or SCl₂ and S₂Cl₂. The thiosulfonium compounds are characterized by vibrational and NMR spectroscopic methods.     

Über Chalkogenolate. 91. Untersuchungen über N-Dicyandithiocarbamidsäure 4. Darstellung und Eigenschaften von Metall (I,II)-N-dicyandithiocarbamaten

On Chalcogenolates. 91. Studies on N-Dicyandithiocarbamic Acid. 4. Preparation and Properties of Metal (I,II) N-Dicyandithiocarbamates The prepared N-dicyandithiocarbamates M[S₂C-N(CN)₂] with M = Cu, Tl as well as M[S₂C-N(CN) ₂]₂ with M = Ba, Pb, Cd, Hg, Co have been investigated by different methods.     

Salze von Halogenophosphorsäuren. XIII. Über Darstellung und Reaktionen von Dihalogenodithiophosphaten

Salts of Halogenophosphoric Acids. XIII. Preparation and Properties of Dihalogeno Dithiophosphates The reaction of the dithiophosphoric acid chloride betaine Py · PS₂Cl (Py = pyridine) with hydrogen halides leads to the corresponding dihalogeno dithiophosphates. Difluorodithiophosphate is formed by the reaction of Py · PS₂Cl with saturated aqueous fluoride (40% yield). Some properties and reactions of the isolated dihalogeno dithiophosphates are reported.     

Zur Kenntnis von Dinitrito-kobalt(III)-Komplexen. II Kinetik der Isomerisierung und der Umsetzung von cis- und trans-Dinitrito-di(äthylendiamin)-kobalt(III)-perchloraten mit Stickstoffwasserstoffsäure

On Dinitrito Cobalt(III) Complexes. II. Kinetics of Isomerisation and Reaction of Cis and Trans Dinitrito Di(ethylenediamine) Cobalt(III) Perchlorates with Hydrazoic Acid After a reinvestigation of the kinetic data of the nitrito-nitro isomerisation of cis and trans dinitrito-di(ethylenediamine) cobaltic perchlorate, the kinetics of the reactions between both coordination compounds and hydrazoic acid, to yield the diaquo compounds, nitrogen and dinitrogen oxide, has been studied by gasvolumetric measurements in the temperature range from 1 to 15°C. In azide buffer solutions both reactions proceed independently of pH, in two stages bimolecular with regard to the complex ion and hydrazoicacid. In both cases the first stage velocity constant is five times greater than the second constant. The cis-compounds react approximately three times faster than the trans-compounds. Possible reasons for the observed facts are discussed.