Ring parameter

The C3S11XY geometry is also found, but involving a chelate ring as in the set136 of molecules (15), Me2SnX (1,4-cyclohexadiene-COOMe) for X = Cl, Br, I and also Me. When X = F, a further very weak interaction occurs (Sn- -F = 364.1 pm) to form a six-coordinate dimer with an unsymmetric Sn—F- -Sn—F- four-membered ring. Parameters are listed in Table 8. 

We observe structural changes in the glycosidic torsion angle(s) (monitored at the H-l protons) and the sugar ring parameters (monitored at the H-3 protons) of poly(dA-dT) on proflavine complex formation. 

An earlier structure of a vinyl-substituted alkenyl ketone metallocycle displayed similar ring parameters and first exposed the carbenoid character... 

I. Further work from Liu s group has involved B-strain and solvolytic reactivity revisited. Nucleophilic solvent participation and abnormal rate ratios for tertiary chloroalkanes. The abnormal rate ratios are those involving introducing FV, and are considered due to competition between B strain and nucleophilic solvent participation. In presenting solvolytic studies of 4-methoxybenzyl chloride and bromide, and of l-(4-methoxyphenyl)ethyl chloride, further opportunity was taken to criticize the introduction and use of the aromatic ring parameter /. ... 

Thus, aromatic polymers are more resistant to dry etching than aliphatic polymers in general and in aliphatic polymers cyclization can reduce the number of hydrogen atoms and therefore N/Nc. As this model showed a poor relationship to chemical structure for etch rates in largely chemical etching, an additional parameter based on polymer structure, called the ring parameter (r) was introduced by Kunz et al. [228], which is defined as... 

Ab initio calculations on 2H-azaphosphirenes and their pentacarbonylme-tal complexes lent further support to this interpretation by showing that the main effect of the metal-coordination onto the ring parameters is a shortening and assimilation of the P,C and P,N bonds (Fig. 2) the endocyclic angles were determined to C-P-N 39.1, P-N-C 67.4, and N-C-P 71.5 [°] (B3LYP/6-31 g(d) + ZPE) [27]. 

The oil ring parameters Investigated with respect to their effect on oil delivery are as follows ... 

The solvolyses of p-methoxybenzyl chloride in 39 solvents are well correlated by an extended Grunwald-Winstein equation involving terms in Tci (solvent ionizing power), At (solvent nucleophilicity) and I (Kevill s aromatic ring parameter). A claim by Liu that nucleophilic participation is greater than in the solvolyses of the corresponding bromide is discussed and said to be disproved. 

The data of Table 9.9 for T =1.3, with a vibrational contribution added from equation (9.74), are compared with the STRAPP prediction in Figure 9.13. The simulation was carried out for the model fluid with the ring parameter B = 0.1756 nm a value consistent with the Lennard-Jones a and parameters. The vibrational contribution is a constant for the isotherm. Since the uncertainty in the STRAPP experimental data is about 10%, the agreement between the STRAPP curve and the simulated data is considered reasonable, and it could be improved by manipulating the potential parameters and the ring size. 

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