Tuning ground states of bis(triarylamine) dications: from a closed-shell singlet to a diradicaloid with an excited triplet state

Yuanting Su; Xingyong Wang; Xin Zheng; Zaichao Zhang; You Song; Yunxia Sui; Yizhi Li; Xinping Wang

doi:10.1002/anie.201309458

Tuning ground states of bis(triarylamine) dications: from a closed-shell singlet to a diradicaloid with an excited triplet state

Angew Chem Int Ed Engl. 2014 Mar 10;53(11):2857-61. doi: 10.1002/anie.201309458. Epub 2014 Feb 3.

Authors

Yuanting Su¹, Xingyong Wang, Xin Zheng, Zaichao Zhang, You Song, Yunxia Sui, Yizhi Li, Xinping Wang

Affiliation

¹ State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093 (China).

PMID: 24497377
DOI: 10.1002/anie.201309458

Abstract

Three bis(triarylamine) dications were isolated by using weakly coordinating anions. Their electronic structures in the ground state were investigated by various experiments in conjunction with theoretical calculations. The ground-state electronic structures of these species were tunable by substituent effects, with two of them as closed-shell singlets and one of them as an open-shell singlet in the solid state. The excited state of the latter is thermally accessible, indicated by EPR and SQUID measurements. The work provides a new and stable diradicaloid structure motif with an excited triplet sate.

Keywords: bis(triarylamine); cations; radicals; substituent effects; triplet state.