The 14N nuclear relaxation times of acetonitrile (CH3CN) solutions of manganese(II) perchlorate have been studied as a function of temperature. Saturation studies have shown that a scalar coupling mechanism controls the relaxation of the 14N nucleus in the coordination sphere of the Mn(II) ion. A determination of the kinetic parameters for the exchange of CH3CN from the first coordination sphere of Mn(II) yielded a first-order rate constant, k1, at 25° of (1.2 ± 0.3) × 107 sec-1, a ΔH≠ for exchange of 7.25 ± 0.25 kcal/mol, and a ΔS≠ for exchange of -1.8 ± 0.8 eu. The value determined for the scalar coupling constant, A/h, was 3.2 × 106 Hz.
ASJC Scopus subject areas
- Physical and Theoretical Chemistry
- Inorganic Chemistry