Formation of High-Spin States (<i>S</i> = 3/2 and 2) in Linear Oligo- and Polyarylamines

This article describes the study of a linear trimer and three polyarylamines <b>PB1–3</b> containing a 3,4′-biphenyl ferromagnetic coupler. The synthesis of the model compound (trimer) and the polymers has been presented. The formation of radical cations was studied using electrochemical and optical (UV–vis) methods. The chemical oxidation of these compounds leads to the creation of high-spin states, evidenced by pulsed EPR nutation spectroscopy. A quartet spin state is observed for the trimer model compound, and its <i>J</i> exchange coupling constant has been measured experimentally (<i>J</i>/<i>k</i> = 11.8 K) and compared quantitatively to DFT calculations. Most importantly, quartet and quintet spin states have been formed for <b>PB3</b> and <b>PB2</b>, respectively. These last two doped polymers thus exhibit the highest spin states observed to date for linear polyarylamine compounds

Tuning of Ferromagnetic Spin Interactions in Polymeric Aromatic Amines via Modification of Their π‑Conjugated System

Polyarylamine containing <i>meta–para–para</i>-aniline units in the main chain and <i>meta–para</i>-aniline units in the pendant chains was synthesized. The polymer can be oxidized to radical cations in chemical or electrochemical ways. The presence of <i>meta</i>-phenylenes in the polymer chemical structure allows for the ferromagnetic coupling of electronic spins, which leads to the formation of high spin states. Detailed pulsed-EPR study indicates that the <i>S</i> = 2 spin state was reached for the best oxidation level. Quantitative magnetization measurements reveal that the doped polymer contains mainly <i>S</i> = 2 spin states and a fraction of <i>S</i> = 3/2 spin states. The efficiency of the oxidation was determined to be 74%. To the best of our knowledge, this polymer is the first example of a linear doped polyarylamine combining such high spin states with high doping efficiency

Tuning of Ferromagnetic Spin Interactions in Polymeric Aromatic Amines via Modification of Their π‑Conjugated System

Polyarylamine containing <i>meta–para–para</i>-aniline units in the main chain and <i>meta–para</i>-aniline units in the pendant chains was synthesized. The polymer can be oxidized to radical cations in chemical or electrochemical ways. The presence of <i>meta</i>-phenylenes in the polymer chemical structure allows for the ferromagnetic coupling of electronic spins, which leads to the formation of high spin states. Detailed pulsed-EPR study indicates that the <i>S</i> = 2 spin state was reached for the best oxidation level. Quantitative magnetization measurements reveal that the doped polymer contains mainly <i>S</i> = 2 spin states and a fraction of <i>S</i> = 3/2 spin states. The efficiency of the oxidation was determined to be 74%. To the best of our knowledge, this polymer is the first example of a linear doped polyarylamine combining such high spin states with high doping efficiency

Tuning of Ferromagnetic Spin Interactions in Polymeric Aromatic Amines via Modification of Their π‑Conjugated System

Polyarylamine containing <i>meta–para–para</i>-aniline units in the main chain and <i>meta–para</i>-aniline units in the pendant chains was synthesized. The polymer can be oxidized to radical cations in chemical or electrochemical ways. The presence of <i>meta</i>-phenylenes in the polymer chemical structure allows for the ferromagnetic coupling of electronic spins, which leads to the formation of high spin states. Detailed pulsed-EPR study indicates that the <i>S</i> = 2 spin state was reached for the best oxidation level. Quantitative magnetization measurements reveal that the doped polymer contains mainly <i>S</i> = 2 spin states and a fraction of <i>S</i> = 3/2 spin states. The efficiency of the oxidation was determined to be 74%. To the best of our knowledge, this polymer is the first example of a linear doped polyarylamine combining such high spin states with high doping efficiency

Tuning of Ferromagnetic Spin Interactions in Polymeric Aromatic Amines via Modification of Their π‑Conjugated System

Polyarylamine containing <i>meta–para–para</i>-aniline units in the main chain and <i>meta–para</i>-aniline units in the pendant chains was synthesized. The polymer can be oxidized to radical cations in chemical or electrochemical ways. The presence of <i>meta</i>-phenylenes in the polymer chemical structure allows for the ferromagnetic coupling of electronic spins, which leads to the formation of high spin states. Detailed pulsed-EPR study indicates that the <i>S</i> = 2 spin state was reached for the best oxidation level. Quantitative magnetization measurements reveal that the doped polymer contains mainly <i>S</i> = 2 spin states and a fraction of <i>S</i> = 3/2 spin states. The efficiency of the oxidation was determined to be 74%. To the best of our knowledge, this polymer is the first example of a linear doped polyarylamine combining such high spin states with high doping efficiency

Tuning of Ferromagnetic Spin Interactions in Polymeric Aromatic Amines via Modification of Their π‑Conjugated System

Polyarylamine containing <i>meta–para–para</i>-aniline units in the main chain and <i>meta–para</i>-aniline units in the pendant chains was synthesized. The polymer can be oxidized to radical cations in chemical or electrochemical ways. The presence of <i>meta</i>-phenylenes in the polymer chemical structure allows for the ferromagnetic coupling of electronic spins, which leads to the formation of high spin states. Detailed pulsed-EPR study indicates that the <i>S</i> = 2 spin state was reached for the best oxidation level. Quantitative magnetization measurements reveal that the doped polymer contains mainly <i>S</i> = 2 spin states and a fraction of <i>S</i> = 3/2 spin states. The efficiency of the oxidation was determined to be 74%. To the best of our knowledge, this polymer is the first example of a linear doped polyarylamine combining such high spin states with high doping efficiency