LLLL L X and Complexes

A study of the acid hydrolysis [equations (1)—(3)] of the a- and j8-[Co(edda)COs] ons at high acidity extends a previous study between pH 1 and 5.  

At the higher pH values the rate-determining step is ring-opening (Ato i) but as the acidity inoreases a limiting rate k is eventually attained. Rate constants and activation parameters associated with Ato, ki, and k, are collected in Table 8. A 

Two more studies have appeared concerned with the effects of macrocyclic ligands upon the rates of aquation of cobalt(in) complexes. The complexes irons-[Co(L)(X)N3] have been prepared [L = (16), X = Cl or Br L = (17), X = Cl, Br, Ns, or HsO] and the rates of aquation studied and compared with data for the analogous complexes of cyclam [L = (18)]. The rates of aquation of corresponding complexes vary in the order (18) (16) (I7) at 298.1 K relative rates are 1 440 2400 and 1 58 260 for X = Cl and Br respectively. The relative rates of 

The only report involving a complex of a quinquedentate ligand is for the a-[Co(tetren)Cl] + ion. The rate constant for hydrolysis is given by A =Ara+A b[OH ] as expected.  

Dioximato-complexes. References to studies of complexes of the type trans-[Co-(dioxime)a(L)X] + are collected in Table 10. When L is an S -bonded sulphinato-ligand, RSOa (R = Me or p-MeC6H4), the trans effect is greater than that of iodide 

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