Dataset Information

Dithienopyrrole Derivatives with Nitronyl Nitroxide Radicals and Their Oxidation to Cationic High-Spin Molecules.

ABSTRACT: Three 1 N-phenyl nitronyl nitroxide (NN) 4-substituted dithieno[3,2-b:2',3'-d]pyrrole (DTP) derivatives with R1=4-phenyl-, 4H-, and 4-methylthiothiophenyl- (R¹ ₂ DTP-Ph-NN, R¹ =H, Ph and MeSTh) were designed, synthesized and characterized. The electrochemical properties were studied by cyclic voltammetry (CV). All the molecules exhibited two main oxidation peaks, first for radical cation and next for dication formation. The cation and dication formation were also confirmed by UV/Vis absorption spectroscopy for Ph₂ DTP-Ph-NN and MeSTh₂ DTP-Ph-NN titrated with tris(4-bromophenyl)aminiumhexachloroantimonate (magic blue). In addition, the cation and dication formation were verified by EPR spectroscopy. Finally, the exchange interactions (J/k_B ) of NN and radical cation were calculated by DFT studies.

SUBMITTER: Kolanji K

PROVIDER: S-EPMC7155055 | biostudies-literature | 2020 Mar

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Dithienopyrrole Derivatives with Nitronyl Nitroxide Radicals and Their Oxidation to Cationic High-Spin Molecules.

Kolanji Kubandiran K Baumgarten Martin M

Chemistry (Weinheim an der Bergstrasse, Germany) 20200228 16

Three 1 N-phenyl nitronyl nitroxide (NN) 4-substituted dithieno[3,2-b:2',3'-d]pyrrole (DTP) derivatives with R1=4-phenyl-, 4H-, and 4-methylthiothiophenyl- (R1 2 DTP-Ph-NN, R1 =H, Ph and MeSTh) were designed, synthesized and characterized. The electrochemical properties were studied by cyclic voltammetry (CV). All the molecules exhibited two main oxidation peaks, first for radical cation and next for dication formation. The cation and dication formation were also ...[more]

PMID: 31872922

Similar Datasets

Project description:EPR spectra of perdeuterated 2,2,6,6-tetramethyl-4-oxopiperidine-1-oxyl (PDT) are studied as functions of molar concentration, c, and temperature, T, in water and 70 wt % glycerol in water. The increase of the intrinsic line width averaged over the three hyperfine lines, B(tot), varies linearly with c with zero intercept in both solvents at all temperatures; therefore dB(tot)/dc is independent of c. The spin exchange induced dispersion, from which the spin exchange frequency, omega(e), may be computed, increases linearly with B(tot), passing through the origin in water and in 70% glycerol at high temperatures; however, at low temperatures, where dipolar interactions broaden the spectra, linearity does not prevail until B(tot) > 1 G due to a contribution of dipolar interactions to the dispersion. The broadening constant due to spin exchange, dB(e)/dc, is found from the slope of the linear region, permitting a computation of the dipolar constant, dB(dip)/dc = dB(tot)/dc - dB(e)/dc. Thus, the separation of concentration broadening into spin exchange and dipolar contributions is effected without having to appeal to some supposed temperature dependence of the two interactions. The fractional broadening by spin exchange, Omega(T), is near unity at high temperatures in both solvents, decreasing to zero in 70% glycerol at 273 K. Omega(T) is a continuous function of the inverse rotational correlation time of PDT but is discontinuous as a function of T/eta where eta is the shear viscosity. Omega(T) = 0.5, where spin exchange and dipolar interactions contribute equally to the line width occurs at T/eta = 20 +/- 1 K/cP in 70% glycerol. Hydrodynamic predictions of dB(e)/dc via the Stokes-Einstein (SE) equation are remarkably accurate in 70% glycerol comparable with the results in a series of alkanes. In water, dB(e)/dc is linear with T/eta with zero intercept as required by the SE; however, with slope a factor of 0.73 smaller. dB(dip)/dc is reasonably predicted by the SE only at very small values of eta/T very quickly following an approximately logarithmic dependence rather that the linear prediction. Values of dB(dip)/dc approach a plateau above eta/T = 0.20 cP/K that is about one-half the solid state limit. Line shifts due to spin exchange are not yet useful to deduce values of Omega(T) due to a lack of knowledge of the time between re-encounters; however, they may be used to verify the values determined from line broadening and spin exchange induced dispersion. Some effects at low temperatures in 70% glycerol suggest that the effects of dipolar interaction are inadequately described by the widely accepted theory.

Dataset Information

Dithienopyrrole Derivatives with Nitronyl Nitroxide Radicals and Their Oxidation to Cationic High-Spin Molecules.

Publications

Dithienopyrrole Derivatives with Nitronyl Nitroxide Radicals and Their Oxidation to Cationic High-Spin Molecules.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets