| Autor: |
Moya HD; Institute de Química, Vniversidade de São Pauto, Caixa Postal 26077, CEP 05599-970, São Paulo, Brazil., Neves EA, Vázquez Suárez-Iha ME, Coichev N |
| Jazyk: |
angličtina |
| Zdroj: |
Talanta [Talanta] 1996 Jan; Vol. 43 (1), pp. 67-72. |
| DOI: |
10.1016/0039-9140(95)01716-X |
| Abstrakt: |
The complex formation between Mn(II) cations and N(3)(-) anions was studied in aqueous medium at 25 degrees C and ionic strength 2.0 M (NaClO(4)). Data of average ligand number, n (Bjerrum's function), were obtained from pH measurements on the Mn(II)/N(3)(-)/HN(3) system followed by integration to obtain Leden's function, F(0)(L). Graphical treatment of data and a matrix solution of simultaneous equations have given the following overall formation constants of mononuclear stepwise complexes: beta(1)=4.15+/-0.02 M(-1), beta(2)=6.61+/-0.04 M(-2), beta(3)=3.33+/-0.02 M(-3), beta(4)=0.63+/-0.01 M(-4). A linear plot of log K(n) vs. (n-1) shows no change in the configuration during complex formation. Slow spontaneous oxidation of solutions to Mn(III) occurs when the N(3)(-) concentration is greater than 1.0 M. |
| Databáze: |
MEDLINE |
| Externí odkaz: |
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