Bradshaw

Bonzel H P, Bradshaw A M and ErtI G 1989 Physics and Chemistry of Aikaii Metai Adsorption (Amsterdam Elsevier)... 

Richardson N V and Bradshaw A M 1981 Electron Spectroscopy Theory, Techniques and Applications vol 4, ed C R Brundle and A D Baker (London Academic)... 

Bradshaw A M 1982 Vibrational speotrosoopy of adsorbed atoms and moleoules App/. Surf. Sci. 11/12 712-29... 

Following Bradshaw [17], we can give the definition of a similarity measure as follows Consider two objects A and B, a is the number of features (characteristics) present in A and absent in B, b is the number of features absent in A and present in B, c is the number of features common to both objects, and d is the number of features absent from both objects. Thus, c and d measure the present and the absent matches, respectively, i.e., similarity while a and b measure the corresponding mismatches, i.e., dissimilarity. The total ntunber of features is n = a + b + c + d. 

A generalisation of the similarity formulae for binary data can be derived, based on the work of Tversky [Tversky 1977 Bradshaw 1997]. This takes the form ... 

Bradshaw J 1997. Introduction to Tversky Similarity Measure. At http //www.daylight.com meetings / mu g97 / Bradshaw / MUG97 / tv tversky.html. 

J, P Willett and J Bradshaw 1997. The Effectiveness of Reactant Pools for Generating turally Diverse Combinatorial Libraries. Journal of Chemical Information and Computer Science 11-740. 

P Willett, J Bradshaw and D V S Green 1999. Selecting Combinatorial Libraries to Optimize rsity and Physical Properties. Journal of Chemical Information and Computer Science 39 169-177. 1 and A W R Payne 1995. A Genetic Algorithm for the Automated Generation of Molecules in Constraints. Journal of Computer-Aided Molecular Design 9 181-202. 

From the data of Jones and Bradshaw, J. Am. Chem. Soc., 55, 1780 (1933). The original data have been converted from (int. ohm) cm"h... 

Physics and Chemistry of Alkali Metal Adsorption," in H. P. Bonzel, A. M. Bradshaw, and G. Erti, eds.. Material Science Monograph, Vol. 57, Elsevier, New York, 1989. 

B. C. Bradshaw, Proceedings of the Annual Power Sources Conferenceil, (1958). 

VI Gillet, P Willett, I Bradshaw. The effectiveness of reactant pools for generating structurally-diverse combinatorial libraries. I Chem Inf Comput Sci 37 731-740, 1997. 

The crown esters are actually macrocyclic lactones, the bulk of which rings are ethyl-eneoxy units. By far, the largest number of such compounds have been prepared by Bradshaw and his co-workers. Representative examples of such compounds are shown below. The name crab ethers has occasionally been applied to such structures, but as with the aquatic species noted above, this name has not found wide acceptance. 

The mixture of diastereomers has been separated into its two principal components by Izatt, Haymore, Bradshaw and Christensen who had previously identified the two principal diastereomers as the cis-syn-cis and cis-anti-cis isomers. Their previous separation technique involved a protracted chromatography on alumina but the new method relied upon the difference in water solubility between the lead perchlorate and hydroniur perchlorate complexes. The lead perchlorate complex is essentially insoluble in aqueous solution and precipitates from it. Using this method, one may obtain 39% of the high-melting polymorph (mp 83—84°) and 44% of the low-melting compound (mp 62—63°). Note that the former also exists in a second crystalline form, mp 69—70°. 

Despite this considerable literature noted above, it was really Bradshaw and coworkers who pioneered the synthesis of macrocyclic ester analogs of crown ethers "... 

Bradshaw and his coworkers have listed several motivations for their explorations in this area. One objective of [the] research program is to prepare and study a series of multi-dentate compounds which resemble naturally occurring macrocyclic compounds . Further, Bradshaw and his coworkers have said that it is our hope that we can prepare macrocycles to mimic the selectivities of the naturally occurring cyclic antibiotics and thereby make available models for the investigation of biological cation transportation and selectivity processes . These workers have presented a number of comparisons with valinomy-cin . The other expressly stated goal of their research is to prepare molecules which will allow us to systematically examine the parameters which affect complex stability and to understand that stability in terms of AH and TAS values for complex formation . 

It should be stressed that there has been considerable interest in macrocycles containing the pyridine subcyclic unit, especially by Newkome and coworkers (see also Chap. 4). Most of his interest appears to have been focussed on polyethers rather than ester compounds. Bradshaw has also reported syntheses of compounds containing the pyridine subcyclic unit. ... 

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