TY - JOUR
T1 - Bistability between π-diradical open-shell and closed-shell states in indeno[1,2-a]fluorene
AU - Mishra, Shantanu
AU - Vilas-Varela, Manuel
AU - Lieske, Leonard Alexander
AU - Ortiz, Ricardo
AU - Fatayer, Shadi
AU - Rončević, Igor
AU - Albrecht, Florian
AU - Frederiksen, Thomas
AU - Peña, Diego
AU - Gross, Leo
N1 - Publisher Copyright:
© The Author(s) 2024.
PY - 2024/5
Y1 - 2024/5
N2 - Indenofluorenes are non-benzenoid conjugated hydrocarbons that have received great interest owing to their unusual electronic structure and potential applications in nonlinear optics and photovoltaics. Here we report the generation of unsubstituted indeno[1,2-a]fluorene on various surfaces by the cleavage of two C–H bonds in 7,12-dihydroindeno[1,2-a]fluorene through voltage pulses applied by the tip of a combined scanning tunnelling microscope and atomic force microscope. On bilayer NaCl on Au(111), indeno[1,2-a]fluorene is in the neutral charge state, but it exhibits charge bistability between neutral and anionic states on the lower-workfunction surfaces of bilayer NaCl on Ag(111) and Cu(111). In the neutral state, indeno[1,2-a]fluorene exhibits one of two ground states: an open-shell π-diradical state, predicted to be a triplet by density functional and multireference many-body perturbation theory calculations, or a closed-shell state with a para-quinodimethane moiety in the as-indacene core. We observe switching between open- and closed-shell states of a single molecule by changing its adsorption site on NaCl. (Figure presented.)
AB - Indenofluorenes are non-benzenoid conjugated hydrocarbons that have received great interest owing to their unusual electronic structure and potential applications in nonlinear optics and photovoltaics. Here we report the generation of unsubstituted indeno[1,2-a]fluorene on various surfaces by the cleavage of two C–H bonds in 7,12-dihydroindeno[1,2-a]fluorene through voltage pulses applied by the tip of a combined scanning tunnelling microscope and atomic force microscope. On bilayer NaCl on Au(111), indeno[1,2-a]fluorene is in the neutral charge state, but it exhibits charge bistability between neutral and anionic states on the lower-workfunction surfaces of bilayer NaCl on Ag(111) and Cu(111). In the neutral state, indeno[1,2-a]fluorene exhibits one of two ground states: an open-shell π-diradical state, predicted to be a triplet by density functional and multireference many-body perturbation theory calculations, or a closed-shell state with a para-quinodimethane moiety in the as-indacene core. We observe switching between open- and closed-shell states of a single molecule by changing its adsorption site on NaCl. (Figure presented.)
UR - http://www.scopus.com/inward/record.url?scp=85184400943&partnerID=8YFLogxK
U2 - 10.1038/s41557-023-01431-7
DO - 10.1038/s41557-023-01431-7
M3 - Article
C2 - 38332330
AN - SCOPUS:85184400943
SN - 1755-4330
VL - 16
SP - 755
EP - 761
JO - Nature Chemistry
JF - Nature Chemistry
IS - 5
ER -