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

Lukasz Skorka (1) , Jean-Marie Mouesca (2) , Lionel Dubois (3) , Ewa Szewczyk (1) , Ireneusz Wielgus (1) , Vincent Maurel (2) , Irena Kulszewicz-Bajer (1)

1 Faculty of Chemistry Technology (Warsaw, Poland)
2 RM - Magnetic Resonance
3 RICC - Reconnaissance Ionique et Chimie de Coordination

This article describes the study of a linear trimer and three polyarylamines PB1-3 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 J exchange coupling constant has been measured experimentally (J/k = 11.8 K) and compared quantitatively to DFT calculations. Most importantly, quartet and quintet spin states have been formed for PB3 and PB2, respectively. These last two doped polymers thus exhibit the highest spin states observed to date for linear polyarylamine compounds.

Keywords: Field-Effect Transistors; Persistent High-Spin; Ground-State; Organic-Molecules; Polycationic States; Conjugated Polymers; Magnetic-Properties; Radical Cations; Phase Crystal

Domains: Physics [physics]

Lukasz Skorka, Jean-Marie Mouesca, Lionel Dubois, Ewa Szewczyk, Ireneusz Wielgus, et al.. Formation of High-Spin States (S=3/2 and 2) in Linear Oligo- and Polyarylamines. Journal of Physical Chemistry B, 2015, 119 (42), pp.13462-13471. ⟨10.1021/acs.jpcb.5b08390⟩. ⟨cea-01745402⟩