A method for simulation of NOESY, ROESY, and off-resonance ROESY spectra

A formalism is proposed for simulation of NOESY, ROESY, and, more specifically, off-resonance ROESY nuclear magnetic resonance spectra. The off-resonance ROESY experiment has several advantages compared to standard NOESY and ROESY experiments. A simplified formalism which allows rapid computer simulation of the development of magnetization, including relaxation, in the presence of an RF field is of general use, in particular in the implementation and interpretation of off-resonance ROESY experiments. The relevant matrix equations can be derived either from the classical Bloch and Solomon equations or from the quantum mechanical homogeneous master equation in the basis of the Cartesian product operators. Examples of simulated spectra and behavior of magnetization during pulse sequences are shown. In addition, we present the full quantum mechanical theory for a two-spin system derived from the homogeneous master equation. The proposed formalism, here applied to off-resonance ROESY, has many potential applications, e.g., in the development and analysis of ROESY and TOCSY mixing sequences, selective pulses, and decoupling in which the complete spin dynamics, including relaxation, is taken into account. (C) 1997 Academic Press.