James F. Wishart, Henry Taube, Kenneth J. Breslauer and Stephan S. Isied
Inorg. Chem. 23, 2997-3001 (1984)
Abstract:
Enthalpies have been obtained for substitution in aquopentaammineruthenium(II) by acetonitrile, imidazole, pyridine, thiodiethanol, pentaammine(pyrazine)ruthenium(II) ion, isonicotinamide, pyrazine, N-methylpyrazinium ion, dimethyl sulfoxide, and carbon monoxide, by using a batch microcalorimeter. The values are -9.2, -9.3, -12.7, -13.7, -13.8, -15.3, -16.8, -18.0, -19.2, and -38.3 kcal mol-1, respectively. Enthalpies were also obtained for the protonation of pentaammine(pyrazine)ruthenium(II) ion (-4.9 kcal mol-1) and for the comproportionation of [((NH3)5Ru)2pyr]5+ (-3.9 kcal mol-1). The enthalpies for the association of pentaammine(pyrazine)ruthenium(II) ion with H+ and aquopentaammineruthenium(II) are compared with published values for Ni2+(aq), Cu2+(aq), and Zn2+(aq).