Hydrogen dynamics

Electronic properties generally do not depend on mass or lifetime therefore the adiabatic total-energy surfaces and also the electronic structure of muonium should be very similar to that of hydrogen. However, its dynamical behavior (zero-point motion, vibrational frequencies, diffusion,. ..) may differ from that of H because of the difference in mass. Most of the results discussed in this chapter will be applicable to both hydrogen and muonium (although for convenience I will usually refer to hydrogen). Dynamical features that may be distinct for the hydrogen vs. muonium cases will be discussed in Parts VI and VII, respectively. 

The hydrogenation of a-amino ketones was also a key step for the synthesis of three more pharma actives (Fig. 37.25). Roche [95] divulged a pilot process involving the hydrogenation/dynamic kinetic resolution of a cyclic a-amino ketone using an optimized MeO-biphep ligand. The Ru-catalyzed reaction was carried out on a 9-kg scale with excellent enantio- and diastereoselectivities, and very... 

Fig. 37.27 Hydrogenation/dynamic kinetic resolution of a penem intermediate.

Welch, C. (2007). HyDIVE (Hydrogen Dynamic Infrastructure and Vehicle Evolution) model analysis. Hydrogen Analysis Workshop, August 9—10. Washington ... 

SLR time results provide novel information on the temperature dependence and distribution of local RFs and their dynamics. A direct evidence for incoherent phonon-assisted deuteron tunnelling in H-bonded systems has been observed from NMR experiments. The use of quadrupole-perturbed ID 2H NMR spectroscopy and in particular 2D 2H NMR exchange spectroscopy has found to be very promising as regards elucidating the details of the hydrogen dynamics. 

G. Auffermann, G. Barrera, D. Colognesi, G. Corradi, A.J. Ramirez-Cuesta M. Zoppi (2004). J. Phys. C Condens. Matter, 16, 5731-5743. Hydrogen dynamics in heavy alkali metal hydrides obtained through inelastic neutron scattering. 

These INS studies of the alkali metal hydrides provide an excellent example of the careful analysis of INS experimental data. It includes the application of corrections for multiple scattering, neutron absorption and heavy-ion scattering the extraction of quantities related to the hydrogen dynamics (the hydrogen mean square displacement, mean kinetic energy and the hydrogen Einstein frequency) and provided the density of vibrational states for each type of atom, shown individually and ab initio modelling of the full INS spectra. 

The hydrogenation/dynamic kinetic resolution shown in Scheme 32 for the production of a penem antibiotic intermediate is carried out by Takasago [72] on a scale of 50-120 t/year, and recently, it was reported that an optimized segphos ligand [81] can achieve even higher stereoselectivities. Similar results were claimed by Chemi [82] with a Ru/tmbtp catalyst. 

Scheme 32 Hydrogenation/dynamic kinetic resolution for a penem antibiotics intermediate...

Scheme 35 Hydrogenation/dynamic kinetic resolution process for Ro 67-8867 (Roche)...

Yang Y, Meuwly M (2010) A generalized reactive force field for nonlinear hydrogen bonds hydrogen dynamics and transfer in malonaldehyde. J Chem Phys 133 064503... 

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