Showing papers on "Ethylenediamine published in 1978"
50 citations
48 citations
TL;DR: Chromatographic separations of the optical isomers of cobalt(III) complexes have been examined with potassium antimony d -tartrate as eluent, and adjusted retention volumes, separation factors and induced circular dichroism spectra have been determined as discussed by the authors.
46 citations
44 citations
TL;DR: The M(acac)2B and NaM(ac)3 complexes have been prepared and their i.r. spectra determined over the 3500-140 cm−1 range as discussed by the authors.
Abstract: The M(acac)2B and NaM(acac)3 complexes (M = Coll, Nill orZnll; 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.
44 citations
41 citations
TL;DR: The structure of the complex formed between molybdate and the diamine functional group of N-β-aminoethyl-γ-aminopropylsilane (Dow Corning 2-6020) immobilized on a silica substrate is determined and compared with the analogous complex precipitated from solution.
36 citations
TL;DR: In this paper, a new ligand, referred to as H 4 aapen, has been prepared; it is the ethylenediamine Schiff base derivative of o -acetoacetylphenol and has one site with two nitrogen and two oxygen atoms (N 2 O 2 ) and a second site with four oxygens being common to both sites.
35 citations
34 citations
TL;DR: In this paper, the stability constants of parent complexes of CuII NiII and ZnII with histamine and histidine, and of the mixed-ligand complexes of these with, glycine, ethylenediamine, 4,5-dihydroxybenzene-1,3-disulphonate, and 2,2′-bipyridyl were determined by pH titrimetry.
Abstract: Equilibrium studies have been carried out by pH titrimetry to determine the stability constants of the parent complexes of CuII NiII and ZnII with histamine and histidine, and of the mixed-ligand complexes of these with, glycine, ethylenediamine, 4,5-dihydroxybenzene-1,3-disulphonate, and 2,2′-bipyridyl. From titrations in an alkaline medium it is concluded that nickel(II) and zinc(II) ions do not affect the ionization of the pyrrole hydrogen significantly compared to the free ligand, but CuII decreases the relevant pKvalues in the parent complexes by about three orders of magnitude. As a consequence of charge-transfer processes, the deprotonation can also be in-fluenced significantly by the formation of mixed-ligand complexes.
32 citations
Patent•
05 Dec 1978
TL;DR: In this article, an active element in the transition metals family uniformly combined with a refractory porous structure with a specific surface of between 10 and 300 m2 /g and with a pore diameter less than 5000 A. The catalyst and the process are applicable to the ethanolamine-ammonia reaction with a view to producing ethylenediamine, piperazine, and useful byproducts.
Abstract: A catalyst for implementing a process for manufacturing amines from alcoh is composed of an active element in the transition metals family uniformly combined with a refractory porous structure with a specific surface of between 10 and 300 m2 /g and with a pore diameter less than 5000 A. A stabilizer in the form of a sodium-based compound with a sodium content of 0.15 to 20% by weight relative to the weight of the catalyst, and a promoter in the form of a rhodium-based compound with a maximum rhodium content of 0.1% by weight relative to the weight of the catalyst, may be associated with the active metal. The catalyst and the process are applicable to the ethanolamine-ammonia reaction with a view to producing ethylenediamine, piperazine, and useful byproducts.
TL;DR: In this article, the electrochemistry of nine monomeric molybdenum(V)-oxo complexes in dimethylformamide has been investigated by cyclic voltammetry and controlled-potential coulometry at a platinum electrode.
Abstract: The electrochemistry of nine monomeric molybdenum(V)-oxo complexes in dimethylformamide has been investigated by cyclic voltammetry and controlled-potential coulometry at a platinum electrode. MoOC13L (L = o-phenanthroline, ol,a'-bipyridyl), MoOClL2 (L = 8-hydroxyquinoline, 8-mercaptoquinoline), and MoOClL (L = disalicylaldehyde ophenylenediimine, N,N'-dimethyl-N,N'-bis(2-mercaptoethyl)ethylenediamine, N,N'-bis(2-mercapto-2-methylpropyl)ethylenediamine) are facilely reduced by one-electron reductions to Mo(1V) species. (C2H5)4NMoOC12(salicylaldehyde o-hydroxyanil) is reduced in a two-electron step to an Mo(1II) species. None of the complexes are oxidizable in the voltage range used (+OS0 to -2.50 V vs. SCE) to Mo(V1) complexes. Comparison with reduction peaks for molybdenum(V1)-dioxo complexes indicates the Mo(V) monomers are not obtainable by electrochemical reduction of the Mo(V1) complexes, and are, in some cases, thermodynamically unstable to disproportionation into Mo(1V) and Mo(V1). Implications for redox states in molybdenum enzymes are discussed.
TL;DR: In this article, a modified ethylenediamine condensation method is described in which catecholamines dissolved in a borate buffer are convertedd into fluorescent products by oxidation with hexacyanoferrate(III) in the presence of ethylensiamine under alkaline conditions.
TL;DR: In this paper, the thermodynamic stability of the copper+ethylenediamine complex is determined in montmorillonite and a macroreticular sulphonic acid resin using ion exchange data and the complex formation function.
Abstract: The thermodynamic stability of the copper+ethylenediamine complex is determined in montmorillonite and a macroreticular sulphonic acid resin using ion exchange data and the complex formation function. Both methods are in excellent agreement and correspond to an increase in the overall stability constant of 103 for montmorillonite and 101·3 for the resin. The stepwise formation constants text-decoration:overlineK1text-decoration:overlineK2 of the ion exchanged complex are 1011·6 and 1011·5 for montmorillonite and 1011·65 and 109·7 for the resin, as compared with values of 1010·7 and 109·3 for the bulk solution. Some tentative interpretation is offered in terms of a decreased ligand solvation in the ion exchanger.
TL;DR: In this article, the acid-catalyzed decarboxylation of the carbonatotetrakis(pyridine)cobalt(III) complex ion showed there was a rate acceleration in D/sub 2/O solvent consistent with a proton-preequilibration mechanism.
Abstract: A recent study of the acid-catalyzed decarboxylation of the carbonatotetrakis(pyridine)cobalt(III) complex ion showed there to be rate acceleration in D/sub 2/O solvent, consistent with a proton-preequilibration mechanism. This observation directly contradicts the results of a similar study made some years ago of the analogous ion, carbonatobis(ethylenediamine)cobalt(III), for which there appeared to be deceleration in D/sub 2/O solvent. A reinvestigation of the latter reaction over a much wider acidity range has now shown the earlier work to be in error. The previously proposed generalized mechanism for aquation of chelated carbonato complex ions of the form CoN/sub 4/CO/sub 3//sup +/ (N/sub 4/ identical with various tetramine ligand groupings of uni-, bi-, or quadridentate type) has thus been revised to include a proton equilibration step. An unexpected complication arises in the interpretation of the data for the bis(ethylenediamine) complex ion in the acidity range 0.1 < (H/sup +/) < 1.0. Within these limits, the pseudo-first-order rate constant for carbonato chelate ring opening, which includes a (H/sup +/) term, overtakes and exceeds the true first-order rate constant for CO/sub 2/ release. The interesting implications of this unusual first-order successive reaction system are fully explored in the context of the present study.
TL;DR: An isotope shift of 5 ppm per deuterium atom has been observed for the 59Co resonance of tris(ethylenediamine)cobalt(III) chloride ([Co(en)3]Cl3) and hexaammine cobalt-III chloride([Co(NH3)6]CL3] as discussed by the authors.
Abstract: An isotope shift of 5 ppm per deuterium atom has been observed for the 59Co resonance of tris(ethylenediamine)cobalt(III) chloride ([Co(en)3]Cl3) and hexaamminecobalt(III) chloride([Co(NH3)6]Cl3) after exchange of hydrogen for deuterium. The upfield direction of the shift can be readily understood as changes in the ligand-field strength causing changes in the nuclear paramagnetic screening.
TL;DR: The role of the imidazole moiety as a sigma donor and sulfhydryl sulfur as a pi acceptor is observed in VO(AA)2 and VO(ox)(AA) complexes.
TL;DR: In this article, the authors performed a first-order dependence on hydroxide ion activity all over the pH range studied indicating that the contribution of the anionic species of the intermediate is negligible under the experimental conditions.
Abstract: The alkaline hydrolysis of 1,2-diphenyl-3-methylimidazolinium iodide (1) affords N-benzoyl-N-phenyl-N′-methylethylenediamine (2). An intermediate of the reaction, probably 1,2-diphenyl-2-hydroxy-3-methylimidazolidine (8), was isolated by thick layer chromatography. Compound (2) in neutral or alkaline media undergoes intramolecular aminolysis affording N-benzoyl-N-methyl-N′-phenylethylenediamine (3) by benzoyl transfer. Kinetic studies were performed on this reaction over the pH range 11.65–12.80. Compound (2) appears to rearrange by a mechanism which involves the formation and catalysed decomposition of a tetrahedral addition intermediate. This intermediate is the same as that isolated by alkaline hydrolysis of (1). Pseudo-first-order rate constants show a first-order dependence on hydroxide ion activity all over the pH range studied indicating that the contribution of the anionic species of the intermediate is negligible under the experimental conditions. The alkaline hydrolysis of the 1,2-diphenyl-1,4,5,6-tetrahydropyrimidinium iodide (9) allowed the isolation of only the rearranged product N-benzoyl-N-methyl-N′-phenyltrimethylenediamine (10).
TL;DR: In this article, the reactions of [Pd(en)(OH2)2]2 + 2H2O (en = ethylenediamine) with the amino-acids glycine, L-alanine, sarcosine, NN-dimethyl glycine, leucine, phenylalanine and S-methyl-L-cysteine have been studied by potentiometric titrations.
Abstract: The reactions of [Pd(en)(OH2)2]2+(en = ethylenediamine) with the amino-acids glycine, L-alanine, sarcosine, NN-dimethylglycine, L-leucine, L-phenylalanine, L- proline, L-tryptophan, L-methionine, and S-methyl-L-cysteine have been studied by potentiometric titrations. For L-methionine and S-methyl-L-cysteine, equilibria (i) and (ii)[Pd(en)(OH2)2]2++ L–[graphics omitted] [Pd(en)L]++ 2H2O (i), [Pd(en)(OH2)2]2++ HL[graphics omitted] [Pd(en)(HL)]2++ 2H2O (ii) hold in solution, where L–= MeS[CH2]nCH(NH2)CO2–(n= 1 or 2). For the remaining amino-acids only equilibrium (i) is significant.
TL;DR: In this paper, the trans-aquasulphito complex with a first-order rate constant consistent with the equation k = 4.9×10-4[H+]+1.
Abstract: Equilibrium constants K and rate constants kf have been measured, at 25°C and ionic strength of 1.0, for the substitution of the labile water molecule in trans-[aquabis(ethylenediamine)sulphito-cobalt(III)] ion by thiosulphate ion (K = 1.8×102 mol-1 1., kf = 1.27×103 mol-1 1. s-1), thiocyanate ion (2.5×103, 2.75×102), nitrite ion (1.0×103, 2.06×102), azide ion (2.9×102, 2.4×102) ferricyanide ion (-, 1.72×103), hydrogen azide (< 1.2,1.4×10), ammonia (3.0, 6.7) and imidazole (2.6×102, 5.2). The correlation of these rate constants with charge on the incoming ligand, as well as a decrease in the apparent second-order rate constants observed at high concentrations of the anionic ligands, requires a rapid outer-sphere pre-equilibrium step followed by a rate- determining dissociative interchange of the incoming ligand with the bound water molecule. The activation energy of the thiocyanate substitution was found to be 48 kJ mol-1. Aquation of cis- [azidobis(ethylenediamine)-sulphitocobalt(III)] ion, in the range of hydrogen ion concentration between 10-2 and 0.2 M, was found to give the trans-aquasulphito complex with a first-order rate constant consistent with the equation k = 4.9×10-4[H+]+1.0×10-5 s-1 at 25°C and ionic strength 1.0.
TL;DR: In this paper, the interaction between B-form DNA in dilute aqueous solution and [Pt(ethylenediamine) (2,2′ -dipyridine)]2+ (I) and [Cu(2, 2′-dipy)x]2+, x = 1 (II) and 2 (III), by means of linear dichroism (LD) and circular dichroisms (CD).
TL;DR: In this paper, a new equation relating the Ps formation I(o-Ps) to the inhibitor concentration was deduced, which allows to advance some predictions, inter alia the behaviour of the positronium inhibition in solvent mixtures can be inferred.
TL;DR: In this paper, the coordination of metal chelates to tin involves two triply bonded oxygen atoms giving rise to an octahedral environment around SnIV and phenyltin(IV) chlorides.
Abstract: Binuclear complexes of phenyltin(IV) chlorides with transition metal chelates of tetradentate Schiff bases derived from acetylacetone, benzoylacetone oro-hydroxyacetophenone and ethylenediamine or propylenediamine, of the general formula PhnSnCl4-nML (where n = 1 or 2, M = Ni11 or Cu11 and L2−= the Schiff base dianion), have been synthesised and characterized through elemental analysis, conductance and i.r. spectroscopic data. The coordination of metal chelates to tin involves two triply bonded oxygen atoms giving rise to an octahedral environment around SnIV. The molar conductance of the complexes in nitrobenzene shows the presence of the uncoordinated ML and phenyltin(IV) chloride moieties in solution.