TY - JOUR
T1 - Reversible Multicolor Photochromism of Dihydroazulene Crystals
AU - Liepuoniute, Ieva
AU - Commins, Patrick
AU - Karothu, Durga Prasad
AU - Schramm, Stefan
AU - Hara, Hideyuki
AU - Naumov, Pance
N1 - Publisher Copyright:
© 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
PY - 2018/11/2
Y1 - 2018/11/2
N2 - The photochemical conversion of 1,8a-dihydroazulene-1,1-dicarbonitrile (DHA) to vinylheptafulvene (VHF) is a positive T-type photoswitch that is well understood in solution, but has not been explored in the solid state. Upon excitation with UV light, DHA is converted into VHF in the solid state, with a distinct color change from yellow to deep-red, and retention of crystallinity. The structure of the ring-opened product was assigned to syn-VHF using variable-temperature infrared spectroscopy, and determined by X-ray photodiffraction in a crystal enriched with the product by two-photon excitation. A radical pathway becomes an observable photoreaction channel at low temperatures, and includes a strongly colored, short-lived diradical intermediate.
AB - The photochemical conversion of 1,8a-dihydroazulene-1,1-dicarbonitrile (DHA) to vinylheptafulvene (VHF) is a positive T-type photoswitch that is well understood in solution, but has not been explored in the solid state. Upon excitation with UV light, DHA is converted into VHF in the solid state, with a distinct color change from yellow to deep-red, and retention of crystallinity. The structure of the ring-opened product was assigned to syn-VHF using variable-temperature infrared spectroscopy, and determined by X-ray photodiffraction in a crystal enriched with the product by two-photon excitation. A radical pathway becomes an observable photoreaction channel at low temperatures, and includes a strongly colored, short-lived diradical intermediate.
KW - crystallography
KW - dihydroazulene
KW - photochromism
KW - solid state
KW - vinylheptafulvene
UR - http://www.scopus.com/inward/record.url?scp=85058381941&partnerID=8YFLogxK
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UR - http://doi.wiley.com/10.1002/chem.201804677
UR - http://www.mendeley.com/research/reversible-multicolor-photochromism-dihydroazulene-crystals
U2 - 10.1002/chem.201804677
DO - 10.1002/chem.201804677
M3 - Article
C2 - 30388317
AN - SCOPUS:85058381941
SN - 0947-6539
VL - 25
SP - 373—378
JO - Chemistry - A European Journal
JF - Chemistry - A European Journal
IS - 1
ER -