Figure 5.

(A) Pump-probe transient of the nonreactive dimer at 1,200 torr. It can be seen from the lack of a fast decay that proton transfer is not occurring in this species. (B) Pump-probe transient of the nonreactive dimer with one water clustered to it. It can be seen here that an attached water molecule actually facilitates the occurrence of the proton transfer in an otherwise nonreactive species. (C) Pump-probe transient of the nonreactive dimer with two waters clustered to it. The second step of the proton transfer can be seen to occur even more quickly with two waters present.