Abstract
The review is devoted to studies of the kinetics of fast photochemical processes in liquid solutions. With use of abundant experimental data and results of theoretical simulations, it is shown that a nonequilibrium state of the nuclear subsystem plays a key role in ultrafast charge transfer processes. A comparison of different approaches and theories developed in recent years for a quantitative description of fast chemical processes is performed and influence of spectral characteristics of an exciting pulse, as well as that of dynamic properties of solvents on the kinetics of these processes are analyzed. The methods to control the efficiency of photochemical charge transfer reactions in a nonequilibrium mode are systematized.