Browsing by Author "Hague, D. N."

Filter results by typing the first few letters
Now showing 1 - 3 of 3
  • No Thumbnail Available
    Item
    Kinetics of Ternary Complex Formation between Magnesium Species and 5-Nitrosalicylic Acid
    (Journal of the Chemical Society : Faraday Transaction - I. The Chemical Society, London. 1972, 68 (12), 1972) Cayley, G. R.; Hague, D. N.
    The temperature-jump relaxation method has been used to measure the rate constants and activation parameters for the formation and the dissociation of the 1 : 1 complex between magnesium and 5-nitrosalicylic acid (nsa) and of the ternary complexes between nsa and the magnesium-nitrilo- triacetate, -adenosine-S'-triphosphatc and -polytriphosphate complexes. The results are compared with those of a previous study with 8-hydroxyquinoline (oxine) and it is shown that the complex formation data can be rationalized in terms of the normal dissociative model provided the local charge densities on the metal ion and the coordinating atom of the incoming ligand are considered rather than the overall charges. The Huckcl LCAO method has been used to estimate the net charges on the various atoms of nsa2- and the oxine molecule and monoanion.
  • No Thumbnail Available
    Item
    Kinetics of ternary complex formation between nickel(II) species and pyridine-2-azo-p-dimethylaniline
    (Journal of the Chemical Society : Faraday Transaction - I. The Chemical Society, London. 1972, 68 (5), 1972) Cobb, M. A.; Hague, D. N.
    The stopped-flow and temperature-jump relaxation methods have been used to measure the rate constants and activation parameters for the formation and the dissociation of the 1 : 1 complex between nickel(II) and pyridine-2-azo-p-dimethylaniline (PADA) and of the ternary complexes between PADA and the nickel(II)-polytriphosphate, -iminodiacetate, -N-methyliminodiacetate, -nitrilotriacetate, -diethylenetriamine, -triethylenetetramine and -2,2′,2″-triaminotriethylamine complexes. The rate constants at 25°C for the reaction between the Ni(II) complex of 1,4,8,11-tetra-azaundecane(2,3,2-tet) and NH3 are also reported. The series provides further evidence that the number of binding nitrogen atoms on the first ligand has a larger influence on ternary complex formation than its charge.
  • No Thumbnail Available
    Item
    Role of Metals in Enzymatic Reactions: Part 5. Kinetics of Ternary Complex Formation Between Magnesium and Manganese(II) Species and 8-Hydroxyquinoline
    (Journal of the Chemical Society : Faraday Transaction - I. The Chemical Society, London. 1972, 68 (1), 1972) Hague, D. N.; Martin, S. R.; Zetter, M. S.
    The temperature-jump relaxation method has been used to measure the activation parameters for the formation and dissociation of the 1 : 1 complexes between magnesium and manganese(Il) and 8-hydroxyquinoline (oxine) and of the ternary complexes between oxine and the magnesium and mangancse(II) complexes of nitrilotriacetate, uramil-NN-diacctate, adcnosine-5'-diphosphatc, adcnosinc-5 -triphosphate and polytriphosphatc. The results strengthen the previous conclusion that the first ligand has comparatively little influence on the kinetics of the reaction of magnesium with a second ligand,whereas manganese(II) shows similarities to zinc in the reactivity of its complexes. I he enzymatic behaviour of magnesium and mangancsc(ll) is discussed in the light of these results.