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

• excitation wavelength from 470 to 540 nm, while in a series of liquids the position of the emission maximum of NR remained constant within same range of the excitation wavelength. It is concluded that the fluorescence spectrum of NR in PMMA undergoes inhomogeneous broadening due to different surroundings of

• 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

• fluoresce in the red tail of the spectrum. Such inhomogeneous broadening of absorption and fluorescence spectra can explain the observable drift in the fluorescence spectra of NR in PMMA to the red for long wavelength excitation (Figure 4 and Figure S2, Supporting Information File 1). The value of νf

Protonated paramagnetic redox forms of di-o-quinone bridged with p-phenylene-extended TTF: A EPR spectroscopy study

• Nikolay O. Chalkov,
• Vladimir K. Cherkasov,
• Gleb A. Abakumov,
• Andrey G. Starikov and
• Viacheslav A. Kuropatov

Beilstein J. Org. Chem. 2016, 12, 2450–2456, doi:10.3762/bjoc.12.238

• of lines in the EPR spectrum means that inhomogeneous broadening of the lines is absent. The triprotonated species (1·)H3 was synthesized through the reduction of (1)H2 with an equimolar amount of (1)H4 in solution. The oxidation state of the quinone-exTTF-quinone core in (1·)H3 corresponds to that

• fragment of the satellite signal is shielded by the main spectrum. The low-field component of the 33S quartet is well resolved and the HFS pattern arising due to coupling with protons at the p-phenylene bridge, is fully reproduced on the satellite spectrum. There is an inhomogeneous broadening of sulfur