Tetraethylenepentamine, complex

Kinetics and mechanisms of complex formation have been reviewed, with particular attention to the inherent Fe +aq + L vs. FeOH +aq + HL proton ambiguity. Table 11 contains a selection of rate constants and activation volumes for complex formation reactions from Fe " "aq and from FeOH +aq, illustrating the mechanistic difference between 4 for the former and 4 for the latter. Further kinetic details and discussion may be obtained from earlier publications and from those on reaction with azide, with cysteine, " with octane-and nonane-2,4-diones, with 2-acetylcyclopentanone, with fulvic acid, and with acethydroxamate and with desferrioxamine. For the last two systems the various component forward and reverse reactions were studied, with values given for k and K A/7 and A5, A/7° and A5 ° AF and AF°. Activation volumes are reported and consequences of the proton ambiguity discussed in relation to the reaction with azide. For the reactions of FeOH " aq with the salicylate and oxalate complexes d5-[Co(en)2(NH3)(sal)] ", [Co(tetraen)(sal)] " (tetraen = tetraethylenepentamine), and [Co(NH3)5(C204H)] both formation and dissociation are retarded in anionic micelles. 

C7H704Rh, Rhodium(I), dicarbonyl(2,4-pentanedionato)-, 34 128 C7HgN4, Bis(l-pyrazolyl)methane, bpm, complex with nickel(ll), 34 139 CgH5FeKN20, Ferrate(ll), carbonyldicyano-(cyclopentadienyl)-, potassium, 34 172 CgH23Ns, Tetraethylenepentamine, tetren, complex with nickel(ll), 34 147, 148 CgH24B2N4, Diborane(4), tetrakis(dimethyl-amino)-, 34 1... 

The kinetic effects of C02 in the base catalyzed hydrolysis of some carboxylato amine cobalt(III) complexes have been reported (80-82). In the base catalyzed hydrolysis of oxalatopentaammine-cobalt(III) (80), C02 retarded the reaction due to the formation of a virtually unreactive ion-pair, f (N H .) r, 2 2 COi ]. The equilibrium constant for formation of carbonate ion-pairs with (glycinato-O) (tetraethylene-pentamine)cobalt(III), (81) and (o-methoxybenzoato) (tetraethylenepentamine)cobalt(III) (82) were, however, much smaller than for the oxalatopentamminecobat(III) and a very weak rate retardation and virtually no effect was observed in the base catalyzed hydrolysis of the latter two complexes. 

Tetraazaporphyrin, octaphenyl-metallation, 858 Tetraazaporphyrins synthesis, 857 Tetraethylenepentamine metal complexes, 56 Tetraglycine metal complexes, 764 Tetraketones metal complexes, 399 1,3,5,7-Tetraketones metal complexes, 400 Tetramines cyclic... 

Fig. 46a, b. Time dependence of the complexation. (a) conformational changes of the polymer components in the complexes Poly(L-glutamic acid) (PGA)-tetraethylenepentamine, O PGA-pentaethylenehexamine (b) pH change of the complex solutions Poly(acrylic acid) (PAA)-integral-type polycation (10,10-ionene) O PAA-poly(N-vinyl-2-pyrrolidone) (PVPo)... 

Ethylenediamine (en), diethylenetriamine (dien), triethylene-tetramine (trien), and tetraethylenepentamine (tetren) form well characterized complexes with M(ii) ions. Such complexes have been the subjects of a number of NMR exchange studies. (299-303) studies have established the identities of [Cu(en)(H20)4], [Cu(en)2-(HjOjj], and complexes involving both en and sulphosalicylic acid ligands. (299-301) NMR studies have been made on aqueous solutions of [Ni(dien)(H20)3], [Ni(tren)(H20)2], and... 

Similar results were obtained when tetraethylenepentamine was replaced with triethylenetetramine. However, in this case the ligand does not deprotonate. The sixth octahedral position was occupied by hydroxide, and the complex was isolated as the perchlorate, [FeL(OH)] (0104)2. Somewhat related reactions have been carried out in which triethylenetetramine complexes of copper(II) or nickel(II) were treated with acetone (57, 38). 

Iron(II) forms stable complexes with a range of polyethyleneamine and related polydentate amines. There has been considerable research effort devoted to the measurement of the thermodynamics of formation of these complexes in aqueous solution. Thus, for example, ethyl-enediamine forms mono, bis and tris complexes in aqueous media with successive enthalpies of reaction being 21,1,43.5 and 66.3 kJ mol respectively. Similar thermochemical measurements have been made on a number of other polydentate amines, for example diethylenetriamine, 2,2, 2"-tria-minotriethylamine, triethylenetetramine, tetraethylenepentamine and N,N,N, N -tetm(2-aminoethyl)ethylenediamine. ... 

The skeleton types for linear and branched chain Nj polyamine ligands are shown in (87)-(90). Commerically available technical tetraethylenepentamine is a mixture of linear tetren, branched chain trenen and other unidentified materials. Thus it is not surprising, in hindsight, that five-coordinate Cu" complexes of trenen and octahedral Co " complexes of tetren (e.g. CoCKtetren) " ) have been isolated from the technical polyamine. Both Fe " and Cr" also give complexes with the linear tetren, rather than the branched chain isomer. 

Spermine and its analogs are toxic and are used as tumor biomarkers. They are also widely distributed in nature and industry. Therefore, the de-teetion of spermine is necessary. WPS can form stable complexation with spermine with a high association constant. When different diamine compounds (10 M), such as spermine, ursol, tetraethylenepentamine, triethylenetetramine, ethanediamine, 1,12-dodecylamine and 1,6-hexa-methylenediamine, are added to an aqueous solution of WP5-stabilized silver nanopartieles, respeetively, the yellow color of the solution containing spermine and its analogs (spermine, tetraethylenepentamine, and triethylenetetramine) becomes black, accompanied by a great decrease of the absorbance peak at 400 nm. However, other diamine compounds have little influence on the color and absorption peaks. All the experimental facts can be ascribed to the seleetive response of WP5-stabilized silver nanopartieles... 

Rapid scan spectrophotometry has been used to study the base hydrolysis of ajS5-(salicylato)(tetraethylenepentamine) cobalt(III) (17). The instantaneous color change observed on addition of base to the complex has been attributed to formation of the phenoxide species and this point has been confirmed. Subsequent aquation and base hydrolysis of the phenoxide species then occurs with = 0.116 s and /cqh = 3.32 M s at 25"C. 

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