Grant-Paul rule

Lindeman-Adams [54] and Grant-Paul [55,56] models. In both, the effects of various a, p, y, and 5 substituents on the chemical shielding of a particular carbon are summed. The Lindeman-Adams scheme focuses on saturated hydrocarbons and is therefore most applicable to polyolefins. The Grant-Paul rules apply to saturated carbons, but include corrections for other functional groups. Models which approximate chemical shifts for substituted aromatic [16] and olefinic [57] carbons have also been developed. An example of the use of these calculational schemes is given in Sec. III.B.l. 

As diseussed in Sec. II.G.l, there are several calculational schemes which can be used to estimate chemieal shifts, particularly for The following example demonstrates the use of the Grant-Paul rules, to approx-... 

The application of the Grant-Paul (GP) rule may be demonstrated by calculating the l3C chemical shift of C(25) in 5a-cholestane (291) ... 

The 13C NMR spectrum of 2,6-dimethyloctane can be used for assigning the resonances of the cholestane side chain. Applying the rules proposed by Grant and Paul [85], all signals of the model compound 2,6-dimethyloctane can be identified. The Grant-Paul parameters also helped in identifying the side chain resonances of ergosterol [65 a]. 

Resonance assignments are often made by empirical relationships or rules that relate structural differences to chemical shift differences. These can be based on extensive studies on model compounds as in the case of the Grant-Paul or Lindeman-Adams relationships [1-3] for predicting the chemical shifts of carbon atoms in hydrocarbons and polyhydrocarbons. These have been very valuable for assigning the resonances observed in the spectra of ethylene-propylene copolymers [4,5], propylene-butene-1 copolymers [6,7], hydrogenated polydienes [8-18], and hydrogenated... 

One of the earliest empirical rules for predicting 13C chemical shifts was that of Grant and Paul (169) for alkanes ... 

From the 13C chemical shift data collected in Table 4.1, Grant and Paul [85] deduced their additivity rule for the 13C chemical shifts of alkanes. The signal assignments for the alkanes, also given in Table 4.1, are based on signal intensities and proton decoupling experiments. 

In the case of asymmetric polymers, another approach to the problem of determining tacticity has been to link it to the problem of determining head/tail placement. In some cases (5,5-dimethylnorbomene is a good example) the question of head/tail placement can be resolved by calculating the chemical shift expected for the vinylic carbons on the basis of simple substituent additivity rules of the kind first proposed by Grant and Paul [8]. These... 

An extensive review of this area has been presented by Williams. The structural principles of the polysilanes are the same as those of the alkanes. Thus, the rules applied for alkanes were extended to the silanes. This approach after Paul and Grant, was used by West and Stanislawski to derive Equation [5] for dimethylsilanes. 

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