Scheme 2.
The diagram shows three main states labeled as C1, Ci, and O. The transitions between these states are indicated by arrows. The transition from C1 to Ci and vice versa is shown with bidirectional arrows. Similarly, Ci transitions to O and back with bidirectional arrows. Additionally, there are transitions from O to I LTI and from O to IF, each with its respective bidirectional arrows. The diagram also includes rate constants (k values), indicating the kinetics of the reactions.