Proton ordering, hydrogen bonds systems

Experimentally, this pathway has been well established from IR spectra of the [CpRuH(C0)(PCy3)]/(CF3)30H system in CH2CI2, where large variations in hydride/alcohol ratios did not affect slow transformation of the H H complexes to hydrogen-bonded ion pairs with k values between 1.4 X 10 and 1.6 X 10 s [25]. Activation parameters for this step (Table 10.3) have been determined in hexane [6]. It is probable that a similar mechanism operates for protonation of the hydrides [ReH2(NO)(CO)(PR3)2] with CF3COOH (Table 10.3) in CD2CI2, where the reaction corresponds to first-order kinetics on the acid at hydride/acid ratios > 1 [7]. 

---