Synthesis and structure of (pyridine) bis(acetylacetonato) (1-methyl-1-phenylethylperoxo) cobalt (III)

Synthesis and structure of (pyridine) bis(acetylacetonato) (1-methyl-1-phenylethylperoxo) cobalt(III) complex are described.

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() () (III).

     

Ammonium bis(tetraethylammonium) hexacyanidoferrate(III) trihydrate

In the structure of the title salt, (NH₄)(C₈H₂₀N)₂[Fe(CN)₆]·3H₂O, the O atom of one of the water molecules shares its crystallographic site with the N atom of the ammonium cation in a 1:1 ratio. The second O atom from the two crystallographically independent water molecules is disordered over two positions separated by 0.551 (1) Å. The water molecules and ammonium cations form tetrameric hydrogen‐bonded units that, along with the complex anion, form the hydrophilic part of the structure. The hydrophobic part of the structure, represented by the tetraethylammonium cation, is located in cube‐like cavities of the hydrophilic framework.     

Synthesis and Properties of Tetraamminebis(1-methyl-5-aminotetrazole-N3,N4)cobalt(III) Perchlorate

Physicochemical and explosive properties of tetraamminebis(1-methyl-5-aminotetrazole-N ³,N ⁴) cobalt(III) perchlorate were studied. The possibility of using this compound as priming charge was demonstrated.     

Effect of solvent on reactions of coordination complexes. Part 12: Kinetics and mechanism of chloride substitution reactions ofcis-(chloro)(2-aminoethanol)bis(ethylenediamine) cobalt(III) andcis-(chloro)(1-aminopropan-2-ol)-bis(ethylenediamine) cobalt(III) ions in acidic and basic ethylene glycol-water media

Summary The loss of chloride ion from the title complexes resulted in the predominant formation of the chelated amino-alcohol productscis-[Co(en)₂(NH₂CH₂CH(X)O/H)]^2+/3+ (X=H or Me). The kinetics of chloride release were investigated in aqueous ethylene glycol (EG) media (0 to 80% by wt of EG) at 40°–65°C in acidic media and at 20°–35°C in basic media. The rate constants decreased linearly with increasing mol fraction of the cosolvent. The plots of log kversus D _s ^–1 (S_s=bulk dielectric constant, k=first order or second order rate constants) were essentially linear with negative slopes for the reactions in an acidic medium, and tended to be curved for the base catalysed reactions. The activation enthalpies and entropiesversus X_EG (X_EG=mol fraction of EG) plots indicated extrema which might be associated with the effects of the solvent structural changes on these thermodynamic parameters. The observed solvent isotope effect at 50°C, [HClO₄]=0.010 mol dm^–3 for Cl^– release was lower than the value for the aquation ofcis-[Co(en)₂(alkylamine)Cl]²⁺ complexes reported in the literature. This is consistent with the lack of direct solvent molecule participation in the actual act of substitution at the cobalt(III) centre, as expected for a true intramolecular reaction.Part-11: A. C. Dash and J. Pradhan,Ind. J. Chem.,29A, 167 (1990).     

Kinetics and mechanism of acid and base hydrolysis ofcis-chloro-(benzotriazole)bis(ethylenediamine)cobalt(III) andcis-chloro-(N-methylbenzotriazole)bis(ethylenediamine)cobalt(III) cations

Summary The kinetics of acid hydrolysis ofcis-[CoCl(btzH)(en)₂]²⁺ andcis-[CoCl(btzMe)(en)₂]²⁺ complexes (where btzH = benzotriazole, btzMe =N-methylbenzotriazole and en = ethylenediamine) have been investigated in HClO₄ at ionic strength 1 = 0.25 mol dm^–3 in the 30–40° range. In the 1.0 x 10^–1 to 1.0 X 10^–3 mol dm^–3 acid strength range, the rate of aquation of the [CoCl(btzH)(en)₂]²⁺ cation follows the relationship:-d ln[complex]/dt = k₁ + k₂K_NH[^H+]^–1, where k₁ and k₂ are aquation rate constants of the acid independent and acid dependent steps respectively, and K_NH is the acid dissociation constant of the coordinated benzotriazole.cis-[CoCl(btzMe)-(en)₂]²⁺ undergoes acid independent hydrolysis presumably due to the absence of a labile N-H proton. The base hydrolysis could be followed for thecis-[CoCl(btzMe)(en)₂]²⁺ complex only by measuring hydrolysis rates at 0°.