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Pseudorotation phase angle

The relation between the CCR rates and the pseudorotation phase angle can be calculated using the general formula for /dipole-dipole by converting the values of the projection angles into P and i//ln [47] according to... [Pg.366]

Fig. 16.7 Theoretical curves of the CCR rate as a function of the ribose pseudorotation phase angle P for three different pucker amplitudes (i/m = 30, 35 and 40°. A rotational correlation time of 1.5 ns and a C-H distance of 1.07 A has been used for the calculation. Fig. 16.7 Theoretical curves of the CCR rate as a function of the ribose pseudorotation phase angle P for three different pucker amplitudes (i/m = 30, 35 and 40°. A rotational correlation time of 1.5 ns and a C-H distance of 1.07 A has been used for the calculation.
Pseudorotation The progression of one conformer of a five-membered ring to another conformer. In the case of cyclopentane there is no planar intermediate all conformers have at least one carbon atom out of the plane of the other carbon atoms. The maximum pucker can, in this case, rotate with almost no potential energy barrier between conformers. Each of the multitude of possible conformers can be described in terms of the maximum pucker and the pseudorotation phase angle, that is, where the conformer lies on a pseudorotation cycle (with an arbitrarily chosen origin). [Pg.514]

A particular ring conformer can be described by two parameters, the puckering amplitude (Xm) and the pseudorotational phase angle (P), which can be illustrated by the pseudorotational wheel shown in Figure 21 for a D-aldofuranose [106]. The radius of the circle is and P, which defines the part of the ring that is most puckered. [Pg.153]

Hernadez Daranas et al. have explored the conformations of five-membered ring systems (derivatives of furan), by NMR spectroscopy, molecular dynamic methods (MD) and DFT calculation of J(H,H), J(C.H) and V(C,H) couplings. Couplings were calculated as the functions of pseudorotational phase angles, and compared with the experimental ones. Such an approach allowed identifying ring conformations. [Pg.176]

Figure 3. Sugar pseudorotation phase angles in 400 conformations simulated by Monte Carlo. Left panels evolution of pseudorotation during simulation right panels distribution of pseudorotation. Pseudorotation angles of B- and A-forms are shown in thick lines for comparison. Figure 3. Sugar pseudorotation phase angles in 400 conformations simulated by Monte Carlo. Left panels evolution of pseudorotation during simulation right panels distribution of pseudorotation. Pseudorotation angles of B- and A-forms are shown in thick lines for comparison.
Distribution of sugar puckers (%). in the different ranges of pseudorotation phase angle T , for all three strands in the CGGP and CGGA MD structures, in the 20-200 ps interval. In the... [Pg.295]

In a study of the conformation of 3,3-dimethyl-3-silatetrahydrothiophene two different twist conformations could fit the electron diffraction data well, with a slight preference for the form in which the S and C(5) atoms lay above and below the plane of the remaining three ring atoms. Ab initio calculations at the HF/6-311++G level indicated that this last form was the potential minimum, and so this conformation was assumed in the analysis of the structure. Differences between some parameters were then computed at the MP2(fc)/6-311++G level and used as constraints in the refinement. Refined parameters (rg, 4) included S-C(mean) 182.9(5), Si-C(mean) 188.3(6), C-C 154.1(7) pm, ZCSC 98.6(8) and ZCSiC(ring) 97.7(6)°. The conformation was described in terms of the ring puckering amplitude, 10.7(6) °, and the pseudorotation phase angle, 168.1(44) °. [Pg.383]


See other pages where Pseudorotation phase angle is mentioned: [Pg.366]    [Pg.156]    [Pg.764]    [Pg.212]    [Pg.430]    [Pg.191]    [Pg.212]    [Pg.29]    [Pg.252]    [Pg.44]    [Pg.107]    [Pg.186]    [Pg.189]    [Pg.191]    [Pg.194]    [Pg.314]    [Pg.315]    [Pg.19]    [Pg.377]    [Pg.268]    [Pg.279]   
See also in sourсe #XX -- [ Pg.366 ]

See also in sourсe #XX -- [ Pg.252 ]




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Sugar pseudorotation phase angles conformations

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