Research output: Contribution to journal › Article › peer-review
The Design of Radical Stacks : Nitronyl-Nitroxide-Substituted Heteropentacenes. / Tretyakov, Evgeny; Keerthi, Ashok; Baumgarten, Martin et al.
In: ChemistryOpen, Vol. 6, No. 5, 01.10.2017, p. 642-652.Research output: Contribution to journal › Article › peer-review
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TY - JOUR
T1 - The Design of Radical Stacks
T2 - Nitronyl-Nitroxide-Substituted Heteropentacenes
AU - Tretyakov, Evgeny
AU - Keerthi, Ashok
AU - Baumgarten, Martin
AU - Veber, Sergey
AU - Fedin, Matvey
AU - Gorbunov, Dmitry
AU - Shundrina, Inna
AU - Gritsan, Nina
N1 - Publisher Copyright: © 2017 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.
PY - 2017/10/1
Y1 - 2017/10/1
N2 - The first alkyl chain-anchored heteropentacene, dithieno[2,3-d;2′,3′-d′]benzo-[1,2-b;3,4-b′]dithiophene (DTmBDT), mono- or disubstituted with a nitronyl nitroxide group has been prepared through a cross-coupling synthetic procedure of the corresponding dibromo-derivative (Br2-DTmBDT) with a nitronyl nitroxide-2-ide gold(I) complex. The synthesized nitroxides possess high kinetic stability, which allowed us to investigate their structure and thermal, optical, electrochemical, and magnetic properties. Single-crystal X-ray diffraction of both mono- and diradicals revealed that the nitronyl nitroxide group lies almost in the same plane as the nearest side thiophene ring. Such arrangement favors formation of edge-to-edge dimers, which then form close π-stacks surrounded by interdigitating alkyl chains. Before melting, these nitronyl nitroxide radical substituted molecules undergo at least two different phase transitions (PTs): for the monoradical, PTs are reversible, accompanied by hysteresis, and occur near 13 and 83 °C; the diradical upon heating shows a reversible PT with hysteresis in the temperature range 2–11 °C and an irreversible PT near 135 °C. PTs of this type are absent in Br2-DTmBDT. Therefore, the step-by-step substitution of bromine atoms by nitronyl nitroxide groups changes the structural organization of DTmBDT and induces the emergence of PTs. This knowledge may facilitate crystal engineering of π-stacked paramagnets and related molecular spin devices.
AB - The first alkyl chain-anchored heteropentacene, dithieno[2,3-d;2′,3′-d′]benzo-[1,2-b;3,4-b′]dithiophene (DTmBDT), mono- or disubstituted with a nitronyl nitroxide group has been prepared through a cross-coupling synthetic procedure of the corresponding dibromo-derivative (Br2-DTmBDT) with a nitronyl nitroxide-2-ide gold(I) complex. The synthesized nitroxides possess high kinetic stability, which allowed us to investigate their structure and thermal, optical, electrochemical, and magnetic properties. Single-crystal X-ray diffraction of both mono- and diradicals revealed that the nitronyl nitroxide group lies almost in the same plane as the nearest side thiophene ring. Such arrangement favors formation of edge-to-edge dimers, which then form close π-stacks surrounded by interdigitating alkyl chains. Before melting, these nitronyl nitroxide radical substituted molecules undergo at least two different phase transitions (PTs): for the monoradical, PTs are reversible, accompanied by hysteresis, and occur near 13 and 83 °C; the diradical upon heating shows a reversible PT with hysteresis in the temperature range 2–11 °C and an irreversible PT near 135 °C. PTs of this type are absent in Br2-DTmBDT. Therefore, the step-by-step substitution of bromine atoms by nitronyl nitroxide groups changes the structural organization of DTmBDT and induces the emergence of PTs. This knowledge may facilitate crystal engineering of π-stacked paramagnets and related molecular spin devices.
KW - density functional and ab initio calculations
KW - EPR spectroscopy
KW - fused thiophene
KW - nitronyl nitroxides
KW - π-stacking
KW - DNA-PK
KW - COMPLEXES
KW - EX-SITU GENERATION
KW - OXIDATIVE ADDITION
KW - density functional and ab into calculations
KW - pi-stacking
KW - CARBON-MONOXIDE
KW - PALLADIUM-CATALYZED CARBONYLATION
KW - ARYL HALIDES
KW - ANTIPLATELET ACTIVITY
KW - AMINOCARBONYLATION
KW - CO SOURCE
UR - http://www.scopus.com/inward/record.url?scp=85028860292&partnerID=8YFLogxK
U2 - 10.1002/open.201700110
DO - 10.1002/open.201700110
M3 - Article
C2 - 29046859
AN - SCOPUS:85028860292
VL - 6
SP - 642
EP - 652
JO - ChemistryOpen
JF - ChemistryOpen
SN - 2191-1363
IS - 5
ER -
ID: 9032651