Fluorescence of Cyclopropenium Ion Derivatives.

J Org Chem

Brock University, 1812 Sir Isaac Brock Way , St. Catharines , Ontario L2S 3A1 , Canada.

Published: June 2018

The synthesis of cyclopropenium-substituted amino compounds and analysis of their photophysical properties is described. Systematic structural modifications of these derivatives lead to measurable and predictable changes in molar extinction coefficients, quantum yields, and Stokes shifts. Using time-dependent density functional theory (TD-DFT) calculations, the origin of these trends was traced to internal charge transfer (ICT) coupled with ensuing structural reorganization for select naphthalene functionalized derivatives. Associated with this structural reorganization was an inward gearing of the cyclopropenium ring and twisting of the peri-NMe group into coplanarity with the naphthalene ring system. Further, reinforcement of an intramolecular H-bond (IMHB) in the excited state of these derivatives alludes to the importance of photoinduced H-bonding in this new class of cyclopropenium based fluorophores.

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http://dx.doi.org/10.1021/acs.joc.8b00770DOI Listing

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