Scott rules

Table 11.3—Correlation table in UV/Visible spectroscopy. Woodward-Feiser-Scott rules for the calculation of the absorption maxima for enones and dienones (precision of 3 nm).

Table 1.3 Scotts rules for calculation of %.max of the ET (electron transfer) band of aromatic carbonyl compounds...

Scott rules to estimate the position of the K-band (in ethanol as the solvent) ... 

Peter Scott-Morgan, The Unwritten Rules of the Game, McGraw-Hill, Inc., 1994. 

Data of mean free paths may be found in CRC Handbook of Chemistry and Physics. Since these ranges include many porous catalysts, the intermediate diffusionai range is of practical interest. The subject is treated by Scott Dullien (AlChE J 8 113, 1962). A simpler rule than theirs is that of Pollard Present (Phys Rev 73 762, 1948)... 

In an approach to the stereocontrolled creation of the acyclic side-chain of tetracyclic triterpenoids and other natural products, Trost and his colleagues have converted the acyclic starting compound (29) into the cyclopropanoid intermediate (31) via the diazo-ketone (30). The key step in the scheme is the cleavage of the cyclopropane with lithium dimethylcuprate to give (32). The stereochemistry at C-7 is determined by the configuration of the double bond in (29). The c.d. and u.v. spectra of a series of triterpenoid olefins have been measured. The Scott-Wrixon rules can be used to correlate the sign of the c.d. curves with molecular structure. A... 

These chiroptical properties are compatible with the prediction made by Scott s octant rule 47) which says that both compounds, which have polymethylene bridges in the (—)-regions (see 52), should exhibit (—)-Cotton effects. 

Structural analysis from electronic spectra yields little information because of their relative simplicity. In the 1940s, however, before the advent of more powerful identification techniques, UV/VIS visible spectroscopy was used for structural identification. The study of a great number of spectra of various molecules has revealed correlations between structures and the positions of absorption maxima. The most widely known empirical rules, due to Woodward, Fieser and Scott, involve unsaturated carbonyls, dienes and steroids. Using incremental tables based on various factors and structural features, it is possible to predict the position of the n —> n absorption bands in these conjugated systems (Table 11.3). Agreement between the calculated values and the experimentally determined position of absorption bands is usually good, as can been seen by the following four examples ... 

We will see in due course that there are important correlation rules between atomic term symbols and molecular electronic states, rules that are important in understanding both the formation and dissociation of diatomic molecules. Elementary accounts of the theory of atomic structure are to be found in books by Softley [3] and Richards and Scott [4], Among the more comprehensive descriptions of the quantum mechanical aspects, that by Pauling and Wilson [5] remains as good as any whilst group theoretical aspects are described by Judd [6],... 

It does not matter that essentiality of some other elements (Na, K, Ca, Sr, Si) - if it actually refers to a certain element which cannot be replaced - will be unrelated to biocatalysis e.g., K can be fully replaced by Rb in many organisms (Scott and DeVoe 1954 Lwoff and Ionesco 1947), Ca roles, e.g. in control of cell budding can likewise be fulfilled by Sr and by various REE ions as a rule, while there are specific functions (unknown up to now) for Sr in corals and certain algae and for Ba in desmides, biocatalytic or not. Thus, neither K nor Ca are fundamental as single elements in such organisms. Examples for such different reasons of essentiality include electrolyte balances, changes of membrane permeability or protein shapes... 

Scott and Wrixon have developed a quadrant rule for the c.d. of platinum(ii)-olefin complexes that depends on d-d orbital transitions. Application of the rule to monoterpenes was considered, and generally conformed to expectations based on known absolute configurations, but in some cases (notably 8-pinene) the results were not satisfactory. The complex measured may be that of a-pinene, for which a Cotton curve of the opposite sign is predicted. Further work on the use... 

Table 2.5 Increment Rules for Diene Absorption (Adapted from Scott, 1964)...

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