Figure 10.

Two-step hopping map for electron tunneling through Re^I-modified azurin. Colored contours reflect electron-transport time scales as functions of the driving force for the first tunneling step (ordinate, Int→*ML) and the overall electron-transfer process (abscissa, Cu^I →*ML). The heavy black lines enclose the region in which two-step hopping is faster than single-step tunneling. The dashed black line indicates the driving force for *Re^II(CO)₃(dmp^•−)(His124)|(Trp122)|AzCu^I → Re^I(CO)₃(dmp^•−)(His124)| (Trp122)^•+|AzCu^I ET; the black dot corresponds to *Re^II(CO)₃(dmp^•−)(His124)| (Trp122)|AzCu^I → Re^I(CO)₃(dmp^•−)(His124)|(Trp122)^•+|AzCu^I → Re^I(CO)₃(dmp^•−)(His124)|(Trp122)|AzCu^II hopping. (Reproduced from ref 152 with permission from AAAS.)