Research output: Contribution to journal › Article › peer-review
Synthesis and Characterization of Free and Coordinated Nitroxide and Nitronyl Nitroxide Diradicals with a 2,7-Naphthalene Coupling Unit. / Zlokazov, Mikhail; Zayakin, Igor; Romanenko, Galina et al.
In: Inorganic Chemistry, Vol. 65, No. 12, 16.03.2026, p. 6476-6491.Research output: Contribution to journal › Article › peer-review
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TY - JOUR
T1 - Synthesis and Characterization of Free and Coordinated Nitroxide and Nitronyl Nitroxide Diradicals with a 2,7-Naphthalene Coupling Unit
AU - Zlokazov, Mikhail
AU - Zayakin, Igor
AU - Romanenko, Galina
AU - Bogomyakov, Artem
AU - Smirnova, Kristina
AU - Zaitsev, Konstantin
AU - Fedin, Matvey
AU - Starikov, Andrey
AU - Shangin, Pavel
AU - Syroeshkin, Mikhail
AU - Nasyrova, Darina
AU - Tretyakov, Evgeny
N1 - Mikhail Zlokazov, Igor Zayakin, Galina Romanenko, Artem Bogomyakov, Kristina Smirnova, Konstantin Zaitsev, Matvey Fedin, Andrey Starikov, Pavel Shangin, Mikhail Syroeshkin, Darina Nasyrova, Evgeny Tretyakov; Synthesis and Characterization of Free and Coordinated Nitroxide and Nitronyl Nitroxide Diradicals with a 2,7-Naphthalene Coupling Unit. Inorg. Chem. 30 March 2026; 65 (12): 6476–6491. https://doi.org/10.1021/acs.inorgchem.5c05421 This research was funded by the Russian Science Foundation (25−73-20009).
PY - 2026/3/16
Y1 - 2026/3/16
N2 - A quantum-chemical investigation of nitroxide and nitronyl nitroxide diradicals with a 2,7-naphthalene coupling unit (bis-tert-butylnitroxide DR4, bis-nitronyl nitroxide DR6, and mixed tert-butylnitroxide/nitronyl nitroxide DR5) was carried out to predict conformation-dependent values of the intramolecular interactions. The coupling constants J are positive for symmetrical diradicals with tert-butyl-nitroxide or nitronyl nitroxide moieties (B3LYP/Def2-TZVPP: ∼440 and 60 K, respectively, for the most stable conformations), but it is negative for the mixed DR5 (∼-160 K). The triplet diradical DR4 was allowed to react with Mn(hfac)2 to give a polymer complex [Mn(hfac)2(DR4)]n exhibiting non-linear field dependencies of magnetization at low temperatures due to short-range ordering within the polymer chains. Attempts to synthesize the mixed diradical DR5 revealed that the tert-butyl-nitroxide moiety is not stable and undergoes a previously unobserved degradation pathway to give the corresponding α-carbonyl nitrone. At the same time, diradical DR6 was successfully prepared by using the palladium-catalyzed reaction of 2,7-dibromonaphthalene with a (nitronyl nitroxide-2-ide)(triphenylphosphine)gold complex. Magnetic susceptibility studies proved that the diradical DR6 has the triplet ground state with the energy gap ΔEST = ∼24 and ∼10-18 K in frozen (glassy) solution and solid state, respectively. Surprisingly, naphthalene-2,7-diyl is comparable as a ferromagnetic coupler with m-phenylene, which provides the singlet-triplet energy gap of value ΔEST = ∼46 K.
AB - A quantum-chemical investigation of nitroxide and nitronyl nitroxide diradicals with a 2,7-naphthalene coupling unit (bis-tert-butylnitroxide DR4, bis-nitronyl nitroxide DR6, and mixed tert-butylnitroxide/nitronyl nitroxide DR5) was carried out to predict conformation-dependent values of the intramolecular interactions. The coupling constants J are positive for symmetrical diradicals with tert-butyl-nitroxide or nitronyl nitroxide moieties (B3LYP/Def2-TZVPP: ∼440 and 60 K, respectively, for the most stable conformations), but it is negative for the mixed DR5 (∼-160 K). The triplet diradical DR4 was allowed to react with Mn(hfac)2 to give a polymer complex [Mn(hfac)2(DR4)]n exhibiting non-linear field dependencies of magnetization at low temperatures due to short-range ordering within the polymer chains. Attempts to synthesize the mixed diradical DR5 revealed that the tert-butyl-nitroxide moiety is not stable and undergoes a previously unobserved degradation pathway to give the corresponding α-carbonyl nitrone. At the same time, diradical DR6 was successfully prepared by using the palladium-catalyzed reaction of 2,7-dibromonaphthalene with a (nitronyl nitroxide-2-ide)(triphenylphosphine)gold complex. Magnetic susceptibility studies proved that the diradical DR6 has the triplet ground state with the energy gap ΔEST = ∼24 and ∼10-18 K in frozen (glassy) solution and solid state, respectively. Surprisingly, naphthalene-2,7-diyl is comparable as a ferromagnetic coupler with m-phenylene, which provides the singlet-triplet energy gap of value ΔEST = ∼46 K.
UR - https://www.mendeley.com/catalogue/8fba7634-c271-3799-8c00-f4506e541347/
UR - https://www.scopus.com/pages/publications/105034755260
U2 - 10.1021/acs.inorgchem.5c05421
DO - 10.1021/acs.inorgchem.5c05421
M3 - Article
C2 - 41839704
VL - 65
SP - 6476
EP - 6491
JO - Inorganic Chemistry
JF - Inorganic Chemistry
SN - 0020-1669
IS - 12
ER -
ID: 85167213