Difluorenoheteroles: topological control of π conjugation in diradicaloids and mixed-valence radical ions.

ABSTRACT: Two families of difluorenoheterole diradicaloids were synthesized, featuring isomeric ring systems with distinct conjugation topologies. The two types of difluorenoheteroles contain, respectively, a Chichibabin-like motif (CH) and a newly introduced heteroatom-linked triphenylmethyl dyad (TD-X). Combined experimental and theoretical investigations show that the TD-X systems have reduced quinoidal character but the interaction between formal spin centers is sufficiently strong to ensure a singlet ground state. The singlet-triplet energy gaps in the TD-X difluorenoheteroles are strongly affected by the heterocyclic ring, with values of -4.3 and -0.7 kcal mol^-1 determined for the pyrrole- and thiophene-containing analogues, respectively. In cyclic voltammetry experiments, the TD-X

SUBMITTER: Prajapati B 

PROVIDER: S-EPMC11220597 | biostudies-literature | 2024 Jul

REPOSITORIES: biostudies-literature