title: Open-shell singlet character of stable derivatives of nonacene, hexacene and teranthene.
abstract: The electronic ground states of the recently synthesized stable nonacene derivatives (J. Am. Chem. Soc. 2010, 132, 1261) are open-shell singlets with a polyradical nature instead of closed-shell singlets as originally assumed, according to the unrestricted broken spin-symmetry density functional theory (UBS-DFT) computations (at B3LYP/6-31G*). It is the bulky protecting groups, not the transfer from the open-shell singlet to closed-shell singlet ground state, that stabilizes these longest characterized acenes. Similar analyses also confirmed the open-shell singlet character of the hexacene and teranthene derivatives.
authors.affiliation: Key Laboratory for Biomedical Effects of Nanomaterials and Nanosafety, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing, 100049, China.
authors.forename: Xingfa
authors.initials: X
authors.lastname: Gao
authors.forename: Jennifer L
authors.initials: JL
authors.lastname: Hodgson
authors.forename: De-en
authors.initials: DE
authors.lastname: Jiang
authors.forename: Shengbai B
authors.initials: SB
authors.lastname: Zhang
authors.forename: Shigeru
authors.initials: S
authors.lastname: Nagase
authors.forename: Glen P
authors.initials: GP
authors.lastname: Miller
authors.forename: Zhongfang
authors.initials: Z
authors.lastname: Chen
mesh_terms: D008958:Models, Molecular; D008968:Molecular Conformation; D009930:Organic Chemicals / Q000737:chemistry*; D012666:Semiconductors; D013237:Stereoisomerism
chemical_list: D009930:Organic Chemicals