Malonaldehyde, hydrogen transfer

One of the most well-known examples of intramolecular tunneling is the isomerization of malonaldehyde consisting in hydrogen transfer in the fragment OH O ... 

Figure 6.4. Contour plot, MEP, and in-stanton trajectory for hydrogen transfer in malonaldehyde. (From Benderskii et al. [1993].)...

Liittschwager NOB, Wassermann TN, Coussan S, Suhm MA (2013) Vibrational tuning of the hydrogen transfer in malonaldehyde—a combined FTIR and raman jet study. Phys Chem Chem Phys 14 2211... 

Carrington, T., Jr., Miller, W. H., 1986, Reaction Surface Description of Intramolecular Hydrogen Atom Transfer in Malonaldehyde , J. Chem. Phys., 84, 4364. 

Malonaldehyde, CH2(CHO)2, exists as an intramolecularly hydrogen-bonded enol (86) in the vapour phase. Molecular dynamics calculations suggest that while a short 0—0 distance favours proton transfer to an (identical) tautomer, such proximity is neither a sufficient nor a necessary condition. 

Figure 3. Hydrogen inversion of ammonia(a) and proton transfer in malonaldehyde (b)...

In this paper I have not reviewed the various chemical applications that have utilized the reaction path model. These include work in my research group on the unimolecular isomerization of hydrogen isocyanide (HNC HCN), the unimolecular decomposition of formaldehyde (HpCO H2 + CO), the vinylidene-acetylene rearrangement (H2C=C HCsCHT, and hydrogen atom transfer in malonaldehyde,... 

The previous studies of concerted hydrogen atom and proton transfer in hydrogen-bonded systems have been limited to studies of reaction pathways for simple model systems [4-8] with simple, reduced dimensionality methods for including quantum tunneling [13,14,34,35]. The applicability of modem computational methods to such systems is exemplified by more recent studies of the energetics of intramolecular hydrogen atom transfer in molecules such as malonaldehyde [36-39] and models of... 

Yagi K, Taketsugu T, Hiiao K (2001) Generation of full-dimensional potential eneigy surface of intramolecular hydrogen atom transfer in malonaldehyde and tunneling dynamics. J Chem Phys 115 10647... 

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... 

The instanton theory of tunneling splittings in hydrogen-bonded systems and decay of metastable states in polyatomic molecules was studied by Nakamura et al. [182, 192, 195, 201-204, 216] They formulated a rigorous solution of the multidimensional Hamiltonian-Jacobi and transport equations, developed numerical methods to construct a multidimensional tunneling instanton path, and applied this method to HO [201], malonaldehyde [192, 195], vinyl radical [203], and formic acid dimer [202]. Coupled electron and proton transfer reactions were recently reviewed by Hammes-Schiffer and Stuchebrukhov [209]. 

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