Quantum coherence, hydrogen bonds

A H(detected)- C shift correlation spectrum (conmion acronym HMQC, for heteronuclear multiple quantum coherence, but sometimes also called COSY) is a rapid way to assign peaks from protonated carbons, once the hydrogen peaks are identified. With changes in pulse timings, this can also become the HMBC (l eteronuclear multiple bond coimectivity) experiment, where the correlations are made via the... [Pg.1461]

Here, we present the example of the trans hydrogen bond coupling between the C of the acceptor and the N of the donor h/(N, C ) that is measured by excitation of double-quantum and zero-quantum coherence between the HN and the C nuclei [12] in a protein. Thus, the double-quantum coherence is split by h /(N, C )+ /(N, H) while the zero-quantum coher-... [Pg.151]

VI. Quantum Coherent Phenomena in Structures with Hydrogen Bonds... [Pg.352]

VI. QUANTUM COHERENT PHENOMENA IN STRUCTURES WITH HYDROGEN BONDS... [Pg.469]

In such a way we have reduced our consideration to the problem of one-domain ferromagnetic particle with anisotropy energy described by equations (457) or (460). The problem of the macroscopic and mesoscopic quantum coherence which correspond to the tunnel switching of the magnetic moment between the two equilibrium directions was studied by Garg and Kim [332] in detail. This means that we may apply their results to calculate the tunneling frequency in the case of the hydrogen-bonded chain. Thus the Euclidean action SPe becomes... [Pg.480]

Big Chemical Encyclopedia