Slow chemical exchange in an eight-coordinated bicentered ruthenium complex studied by one-dimensional methods. Data fitting and error analysis

Threefold carbonyl rotation in Ru-2(CO)(6)(mu(2) - PPh(2))(mu(2) - eta(1):eta(2) - C=C - i - Pr) provides an excellent system for studying slow chemical exchange, One-dimensional relaxation-type experiments, in which spin-lattice relaxation and exchange compete, are performed to see if the threefold rotation is concerted, or a series of pairwise exchanges, Crucial to this study are the error estimates of the parameters; thus, methods for data fitting and error analysis are presented. The conclusions are that the process is concerted, and the barrier is approximately 46 kJ/mol. As an appendix, a discussion of the principle of detailed balance in complex systems, such as the present, is given, This solves the standard kinetic problem of what is the equilibrium state which results from a general kinetic scheme. (C) 1996 Academic Press, Inc.