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 Title: Structural Studies of Penetrated Ion Pairs Using Chiral Cyanine Borates Author(s): Owen, David John Doctoral Committee Chair(s): Schuster, Gary B. Department / Program: Chemistry Discipline: Chemistry Degree Granting Institution: University of Illinois at Urbana-Champaign Degree: Ph.D. Genre: Dissertation Subject(s): Chemistry, Organic Abstract: An induced circular dichroism (CD) spectrum is observed for 1,1$\sp\prime,3,3,3\sp\prime,3\sp\prime$-hexamethyl-9-phenyl-indo-carbocyanine, 1,1$\sp\prime$-diethyl-2,2$\sp\prime$-cyanine, 1,1$\sp\prime$-di-(3,5-di-tert-butyl)benzyl-2,2$\sp\prime$-cyanine, or 1,1$\sp\prime$-di-(4-tert-butyl)benzyl-2,2$\sp\prime$-cyanine when penetrated into a chiral cavity of either spirobi- ((2-methyl)borataxanthene) or spirobi- ((3-methyl)borataxanthene). Within the ion pair, the cyanine dye exists in two (or more) interconverting conformations of unequal energy. Solid state structural evidence suggests that a nitrogen-forward mode for penetration by the cyanine dominates the solution behavior. A critical feature for the detection of the induced circular dichroism spectrum is that the dye is twisted in the ground state. The free energy difference between the diastereomers with right- and left-handed twist in the chiral cavity of the borate is less than 1 kcal/mol, but this is sufficient to induce the CD spectrum. The magnitude of observed CD spectrum is dependent on the structure of both the cyanine and borate. Issue Date: 1998 Type: Text Language: English Description: 91 p.Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1998. URI: http://hdl.handle.net/2142/84402 Other Identifier(s): (MiAaPQ)AAI9834726 Date Available in IDEALS: 2015-09-25 Date Deposited: 1998
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