Photochromic spirooxazines functionalized with oligomers: investigation of core-oligomer interactions and photomerocyanine isomer interconversion using NMR spectroscopy and DFT.

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dc.contributor.authorYee, LHen_AU
dc.contributor.authorHanley, TLen_AU
dc.contributor.authorEvans, RAen_AU
dc.contributor.authorDavis, TPen_AU
dc.contributor.authorBall, GEen_AU
dc.date.accessioned2010-06-15T06:06:23Zen_AU
dc.date.available2010-06-15T06:06:23Zen_AU
dc.date.issued2010-05-07en_AU
dc.date.statistics2010-05-07en_AU
dc.description.abstractPhotochromic spirooxazines functionalized with poly(ethylene glycol) (PEG) and poly(dimethylsiloxane) (PDMS) oligomers were monitored using NMR spectroscopy at temperatures between 193 and 233 K before and after in situ exposure to UV irradiation. NOESY and ROESY experiments reveal the TTC (trans−s-trans−cis) isomer to be the dominant merocyanine isomer formed on photolysis, with some CTC (cis−s-trans−cis) isomer also present. Significant ROE cross peaks were observed between the “bulk” of the oligomeric units and protons across the entire photochromic core of the molecule, the intensity of these cross peaks suggesting that the interaction of the oligomer side chain and core of the molecule is significantly enhanced by the permanent attachment, especially with the PDMS side chain. The 2D NMR spectra indicate that there is exchange between the TTC and CTC isomers even at 193 K. This isomerization of the parent spirooxazine compounds, lacking the oligomeric side chains, was found to be acid-catalyzed, and DFT calculations support the strong possibility that it is the protonated merocyanine form that undergoes the facile isomerization process. Interconversion of the different merocyanine isomers is suggested to be fast on the NMR time scale under many experimental conditions, precluding the observation of different isomers using NMR spectroscopy at room temperature. © 2010, American Chemical Societyen_AU
dc.identifier.citationYee, L. H., Hanley, T., Evans, R. A., Davis, T. P., & Ball, G. E. (2010). Photochromic spirooxazines functionalized with oligomers: investigation of core-oligomer interactions and photomerocyanine isomer interconversion using NMR spectroscopy and DFT. Journal of Organic Chemistry, 75(9), 2851-2860. doi:10.1021/jo100081gen_AU
dc.identifier.govdoc1745en_AU
dc.identifier.issn0022-3263en_AU
dc.identifier.issue9en_AU
dc.identifier.journaltitleJournal of Organic Chemistryen_AU
dc.identifier.pagination2851-2860en_AU
dc.identifier.urihttp://dx.doi.org/10.1021/jo100081gen_AU
dc.identifier.urihttp://apo.ansto.gov.au/dspace/handle/10238/1717en_AU
dc.identifier.volume75en_AU
dc.language.isoenen_AU
dc.publisherAmerican Chemical Societyen_AU
dc.subjectPhotochromic materialsen_AU
dc.subjectNuclear magnetic resonanceen_AU
dc.subjectIsomersen_AU
dc.subjectPeaksen_AU
dc.subjectIrradiationen_AU
dc.subjectIsomerizationen_AU
dc.titlePhotochromic spirooxazines functionalized with oligomers: investigation of core-oligomer interactions and photomerocyanine isomer interconversion using NMR spectroscopy and DFT.en_AU
dc.typeJournal Articleen_AU
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