Premium
Towards Magnetic Carbo‐ meric Molecular Materials
Author(s) -
Poidevin Corentin,
Malrieu JeanPaul,
Trinquier Georges,
Lepetit Christine,
Allouti Faycal,
Alikhani M. Esmail,
Chauvin Remi
Publication year - 2016
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.201504493
Subject(s) - diradical , singlet state , delocalized electron , chemistry , phenylene , open shell , molecule , conjugated system , computational chemistry , spin states , chemical physics , materials science , physics , polymer , quantum mechanics , organic chemistry , excited state , inorganic chemistry
Numerous studies have underlined the putative diradical character of π‐conjugated molecules that can be described by closed‐shell Lewis structures, for instance, p ‐dimethylene p –n phenylenes, or long polyacenes. In the latter compounds, the only way to save the aromaticity of the six‐membered rings is to give up the Lewis electron pairing in the singlet biradical ground state. The present work considers the possibility of doing the same by using the basic C 2 units of carbo ‐meric architectures. A series of acyclic and cyclic carbo ‐meric architectures is studied by using UB3LYP DFT broken‐symmetry calculations, including spin decontaminations and subsequent geometry optimization of the singlet diradical. The C 2 units are shown to stabilize the singlet biradical by spin delocalization, two of them playing approximately the same role as one radical‐insulating 1,4 phenylene moiety. The results are generalized to the investigation of open‐shell polyradical singlet states of rigid hydrocarbon structures, the symmetry and rigidity of which can assist cooperativity and self spin polarization effect. Several synthesis targets with challenging magnetic/spin properties are suggested in the carbo ‐mer series.