ISSN:
0018-019X
Keywords:
Chemistry
;
Organic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
The kinetics of the reaction between 1,4,8,11-tetraazacyclotetradecane (Cy) and Ni2+ in the presence of series of ligands L = fluoride, acetate, glycolate, oxalate, malonate, succinate, methanetriacetate, 1,3,5-cyclohexanetriacetate, tricarballylate, picolinate, glycinate, iminodiacetate, nitrilotriacetate. N,N′ -ethylenediiminodiacetate, ammonia, pyridine, ethylenediamine, 1,3-propanediamine and diethylenetriamine were studied by pH-static and spectrophotometric methods at 25° and I = 0.5. By analysis of the log k/log [L] and/or log k/pH profiles the resolved bimolecular rate constants KCyHnNiLm (Table 3) were determined using a non-linear least-square fitting procedure. Practically for all systems the rate constant KCyHNiL, describing the reaction between the 1:1 Ni2+ complex and the monoprotonated form of the macrocycle, was obtained. In some cases, however, also KCyH2NiL and KCyNiL were found. Since the experimental conditions were choosen so that NiL was mainly formed, the reactivity of NiL2 was generally not measurable. The effect of the number of coordinated donor groups in NiL and of the charge of NiL on KCyHNiL is discussed. Both effects seem to indicate that for the reaction between NiL and CyH+ first bond formation is not the rate-determining step.
Additional Material:
3 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/hlca.19840670724
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