Hydrogen bond exchange

The Stahl-Jencks treatment assumes that hydrogen bond formation between A-H and B is really hydrogen bond exchange ... 

Even within the limits of maintaining chemically similar atoms, care is needed when one is invoking transferability. IMPT calculations on amide-amide and amide-water systems indicated that the change in the intermolecular interaction energy associated with the hydrogen bond exchange process... 

Figure 6.43 Conformational isomerism, hydrogen bond exchange and HH-transfer in N,N -di-(p-F-phenyl)amidine (DFFA) dissolved in tetrahydrofuran (S) according to Ref [24cj.

Fig. 2-5 Carbonyl/amide association and hydrogen bond exchange with water.

For a relaxation process in which the mechanism is constant but the energy states between which exchange occurs can have different values of Cole-Cole analysis is appropriate This type of analysis applies to relaxation in polymer molecules and hydrogen bond exchange... 

M. Quack and M. A. Suhm,/. Chem. Phys., 95, 28 (1991). Quasiadiabatic Channels and Effective Transition-State Barriers for the Disrotatory In-Plane Hydrogen-Bond Exchange Motion in (HF)2. 

S. Park, M. Odelius, K.J. Gaffney, Ultrafast dynamics of hydrogen bond exchange in aqueous ionic solutions. J. Phys. Chem. B 113(22), 7825-7835 (2009)... 

By contrast, this process is slow as compared to hydrogen bond exchange. In other words, in each tautomerization another base molecule always carries the same proton back and forth without intermolecular proton exchange. 27 is stable only at low temperatures, but dissociates at higher temperatures. Thus at low... 

Complexes of 2,4,6-trimethylpyridine (collidine) with HF dissolved in CDF3/CDF2CI down to 100 K are depicted in Figure 14.26. The different complexes 41-44 formed could be characterized in the slow hydrogen bond exchange... 

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