Probing of local polarity in poly(methyl methacrylate) with the charge transfer transition in Nile red

• Aydan Yadigarli,
• Qimeng Song,
• Sergey I. Druzhinin and
• Holger Schönherr

Beilstein J. Org. Chem. 2019, 15, 2552–2562, doi:10.3762/bjoc.15.248

• NR molecules in the ground state and slow sub-glass transition (Tg) relaxations in PMMA. Keywords: charge transfer; dipole moment; fluorescence; inhomogeneous broadening; oxazine dye; polarity probe; polymer permittivity; Introduction The chain and segment mobility as well as the permittivity of

• absorption of many biomolecules, and (iii) exhibits fluorescence, which is strongly influenced by the polarity of the environment, it has been employed as a polarity probe in biological applications [16][17][18][19] and materials/nanoscience [15][20][21][22][23]. For instance, the spatial distribution of the

• NR using an Onsager radius of 545 pm. The local environment of NR as local polarity probe molecule in PMMA films demonstrates a local mobility that is higher than that expected from the permittivity of bulk PMMA. The local dielectric constant of 5.9–8.3 implies that beside electronic and atomic