Research output: Contribution to journal › Article › peer-review
Structural Diversity of Calcium, Strontium, and Barium Complexes with Reduced Forms of the 3,6-Di-tert-butyl-o-benzoquinone Ligand. / Sinitsa, Dmitry K.; Sukhikh, Taisiya S.; Petrov, Pavel A. et al.
In: European Journal of Inorganic Chemistry, Vol. 2019, No. 39-40, 31.10.2019, p. 4373-4383.Research output: Contribution to journal › Article › peer-review
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TY - JOUR
T1 - Structural Diversity of Calcium, Strontium, and Barium Complexes with Reduced Forms of the 3,6-Di-tert-butyl-o-benzoquinone Ligand
AU - Sinitsa, Dmitry K.
AU - Sukhikh, Taisiya S.
AU - Petrov, Pavel A.
AU - Nadolinny, Vladimir A.
AU - Konchenko, Sergey N.
AU - Pushkarevsky, Nikolay A.
N1 - Publisher Copyright: © 2019 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
PY - 2019/10/31
Y1 - 2019/10/31
N2 - Molecular complexes of Ca, Sr, and Ba with the reduced forms of 3,6-di-tert-butyl-o-benzoquinone as ligands (catecholate, 3,6-Cat2–, or semiquinone 3,6-SQ–‧) were synthesized and structurally characterized. Trinuclear complexes [M3(3,6-Cat)3(thf)6] (1, M = Ca; 2, M = Sr) or tetranuclear complex [Ba4(3,6-Cat)4(thf)6] (3) crystallize from tetrahydrofuran (thf) solutions. In the structures of 1 and 2 metal atoms form a nearly right triangle with two µ3-bridging 3,6-Cat ligands; in 3, the metal atoms form a tetrahedron contracted along a twofold axis, and all the catecholates are µ3-bridging. In nonpolar media the complexes 1–3 lose coordinated thf, upon which 1 is converted into complex [Ca4(3,6-Cat)4(thf)4] (4), structurally similar to 3. Complex 1 is oxidized by one equivalent of the quinone to yield mixed-ligand complex [Ca3(3,6-SQ)2(3,6-Cat)2(thf)4] (5), structurally similar to 1. Successive oxidation by the quinone leads to dissociation to mononuclear species, [Ca(3,6-SQ)2(thf)3] (5), which possesses pentagonal-bipyramidal coordination with two semiquinolate ligands lying in an equatorial plane. Solution behavior of the complexes is studied by NMR (for catecholates) and EPR (for semiquinolates) spectroscopy.
AB - Molecular complexes of Ca, Sr, and Ba with the reduced forms of 3,6-di-tert-butyl-o-benzoquinone as ligands (catecholate, 3,6-Cat2–, or semiquinone 3,6-SQ–‧) were synthesized and structurally characterized. Trinuclear complexes [M3(3,6-Cat)3(thf)6] (1, M = Ca; 2, M = Sr) or tetranuclear complex [Ba4(3,6-Cat)4(thf)6] (3) crystallize from tetrahydrofuran (thf) solutions. In the structures of 1 and 2 metal atoms form a nearly right triangle with two µ3-bridging 3,6-Cat ligands; in 3, the metal atoms form a tetrahedron contracted along a twofold axis, and all the catecholates are µ3-bridging. In nonpolar media the complexes 1–3 lose coordinated thf, upon which 1 is converted into complex [Ca4(3,6-Cat)4(thf)4] (4), structurally similar to 3. Complex 1 is oxidized by one equivalent of the quinone to yield mixed-ligand complex [Ca3(3,6-SQ)2(3,6-Cat)2(thf)4] (5), structurally similar to 1. Successive oxidation by the quinone leads to dissociation to mononuclear species, [Ca(3,6-SQ)2(thf)3] (5), which possesses pentagonal-bipyramidal coordination with two semiquinolate ligands lying in an equatorial plane. Solution behavior of the complexes is studied by NMR (for catecholates) and EPR (for semiquinolates) spectroscopy.
KW - Alkaline earth metals
KW - Catecholate
KW - Multinuclear complexes
KW - Redox-active ligands
KW - Semiquinolate
KW - CATECHOLATE
KW - OXIDATION
KW - SINGLE-MOLECULE MAGNET
KW - TRANSITION-METAL-COMPLEXES
KW - SEMIQUINONE
KW - EPR
KW - COPPER(II)
KW - IONS
KW - VALENCE TAUTOMERISM
KW - DERIVATIVES
UR - http://www.scopus.com/inward/record.url?scp=85071651764&partnerID=8YFLogxK
U2 - 10.1002/ejic.201900678
DO - 10.1002/ejic.201900678
M3 - Article
AN - SCOPUS:85071651764
VL - 2019
SP - 4373
EP - 4383
JO - European Journal of Inorganic Chemistry
JF - European Journal of Inorganic Chemistry
SN - 1434-1948
IS - 39-40
ER -
ID: 21463968