Browsing by Author "Grant, M. W."

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    Kinetics and Thermodynamics of the Complex-formation of Nickel(II) and Cobalt(II) Ions with Ammonia and Pyridine- 2-azodimethylaniline in Water, at Pressures from 1 bar to 2 kbar
    (Journal of the Chemical Society : Faraday Transaction - I. The Chemical Society, London. 1972, 68 (12), 1972) Caldin, E. F.; Grant, M. W.; Hasinoff, B. B.
    Thermodynamic and kinetic measurements have been made at a series of pressures from 1 bar to 2 kbar on the reactions of nickel(IQ and cobalt(II) ions with ammonia and with the large bidentate ligand PADA (pyridine-2-azodimethylaniline) in aqueous solution. The apparatus consisted of a high-pressure cell and a laser temperature-jump apparatus with spectrophotometric detection. A method is described for determining equilibrium constants at high pressures from the amplitude of the optical-density change on reaction. The values found for AK* are all in the region of 4-5 to + 8 cm3 mol-1. The results are consistent with the interpretation that the transition state involves considerable stretching of the cation-water bond, as postulated in the Eigen-Wilkins mechanism.
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    Kinetics and Thermodynamics of the Formation of the Monoglycinate Complexes of Cobalt(II), Nickel(II)5 Copper(II) and Zinc(II) in Water, at Pressures from 1 bar to 3 kbar
    (Journal of the Chemical Society : Faraday Transaction - I. The Chemical Society, London. 1973, 69 (3), 1973) Grant, M. W.
    The volumes of activation for the formation of the monoglycinate complexes of nickel (ll) cobalt(II), copper (H) and zinc(II) are found to be 8±2, 10± 1, 12± 1 and 7± 1 cm3 mol-1, respectively. After allowance has been made for the volume change accompanying outer-sphere complex formation, these values are similar to those found for the reactions of nickel(II) and cobalt(II) with ammonia and pyridine-2-azodimcthylaniline, and are likewise interpreted, in terms of the Eigen mechanism for ligand substitution, as resulting from the stretching of a metal-water bond.