Allocation of Ambipolar Charges on an Organic Diradical with a Vinylene–Phenylenediyne Bridge

Two redox and magnetically active perchlorotriphenylmethyl (• PTM) radical units have been connected as end-capping groups to a bis(phenylene)diyne chain through vinylene linkers. Negative and positive charged species have been generated, and the influence of the bridge on their stabilization is discussed. Partial reduction of the electron-withdrawing • PTM radicals results in a class-II mixed-valence system with the negative charge located on the terminal PTM units, proving the efficiency of the conjugated chain for the electron transport between the two terminal sites. Counterintuitively, the oxidation process does not occur along the electron-rich bridge but on the vinylene units. The • PTM radicals play a key role in the stabilization of the cationic species, promoting the generation of quinoidal ring segments.This work was supported by the MICINN of Spain (Projects CTQ2016-80030-R, PGC2018-099568-B-I00 (EU Feder Funds), PID2019-111682RB-I00, Severo Ochoa FUNFUTURE CEX2019-000917-S, and María de Maeztu CEX2019- 000919-M), the Generalitat de Catalunya (2017-SGR-918), the Generalitat Valenciana (PROMETEO/2020/077), and the Networking Research Center on Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN) Development Fund. P.M.- B. gratefully thanks financial support from the Juan de la Cierva-Formación 2015 programme (FJCI-2015-23577) supported by MICINN. F.B. thanks the MECD for a predoctoral FPU fellowship. J.C. acknowledges the Generalitat Valenciana (APOSTD/2017/081). J.A.d.S. is enrolled in the Materials Science doctoral program of the UAB. J.A.d.S. thanks the MINECO for the FPI-SO fellowship. The authors acknowledge A. Bernabé from ICMAB for the MALDI-ToF measurements and Dr. Mireia Díaz and Dr. Marta Vilaseca, from the IRB Barcelona Mass Spectrometry and Proteomics Core Facility (unity member of ProteoRed, PRB3-ISCIII, supported by Grant PRB3 (IPT17/0019-ISCIII-SGEFI/ERDF), for the ES+ ToF MS experiments. The work in Durham was supported by the EC FP7 ITN project MOLESCO (606728).Peer reviewe