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Schuster, Gary B. Owen, David John 2015-09-25T22:14:18Z 2015-09-25T22:14:18Z 10000-01-01 1998 1998 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. Made available in DSpace on 2015-09-25T22:14:18Z (GMT). No. of bitstreams: 2 license.txt: 4848 bytes, checksum: 96035ab3f5e1c23cc7138a224ce498bd (MD5) 9834726.pdf: 4823130 bytes, checksum: 9b7cc85790f65c8e10b34bc5e16979a9 (MD5) Previous issue date: 1998 Embargo set by: Seth Robbins for item 85683 Lift date: Forever Reason: Restricted to the U of I community idenfinitely during batch ingest of legacy ETDs Restricted to the U of I community idenfinitely during batch ingest of legacy ETDs U of I Only 91 p. Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1998. http://hdl.handle.net/2142/84402 (MiAaPQ)AAI9834726 eng Chemistry, Organic Structural Studies of Penetrated Ion Pairs Using Chiral Cyanine Borates text Chemistry Chemistry University of Illinois at Urbana-Champaign Dissertation Ph.D.