Abstract: Reaction of Cu(hfac)2 with methyl- and bromo-3-pyridyl-substituted nitronyl nitroxides (LR) leads to assemble a diverse set of coordination complexes: mononuclear [Cu(hfac)2L2-Me], binuclear [{Cu(hfac)2}2(H2O)L2-Me], trinuclear [{Cu(hfac)2}3(L6-Br)2], pentanuclear [{Cu(hfac)2}5(L2-Me)2], and [{Cu(hfac)2}5(L2-Me)4], cocrystals [Cu(hfac)2(L2-Br)2]·[Cu(hfac)2(H2O)2] and [Cu(hfac)2(L2-Br)2]·2[Cu(hfac)2H2O], one-dimensional polymers [Cu(hfac)2L2-Br]n and [Cu(hfac)2L6-Br]n, and cyclic dimers [Cu(hfac)2L5-Me]2, [Cu(hfac)2L5-Br]2, and [Cu(hfac)2L6-Me]2. The molecular structures of the obtained complexes are strongly affected by the substituent type and its location in the pyridine heterocycle. Occupation of the second position of the pyridine ring increases the steric hindrance of both imine and nitroxide coordination sites of L2-R, which is favorable for the formation of various conformers and precipitation of complexes with different molecular structures. The pentanuclear [{Cu(hfac)2}5(L2-Me)2] and [{Cu(hfac)2}5(L2-Me)4] complexes do not have prior analogues and are valuable model objects for investigation of the mechanism of formation of various coordination polymers. The arrangement of long Cu–ONO bonds in {CuO6} square bipyramids due to the weakening nitroxide donor site in complexes, based on L2-Me, L2-Br, and L6-Br ligands, results in ferromagnetic exchange interactions between spins of Cu2+ ions and nitroxides. Complexes with substituents that do not considerably affect the coordination ability of ligands (L5-Me, L5-Br, and L6-Me) exhibit strong antiferromagnetic exchange interactions between spins of Cu2+ ions and nitroxides.

Cite: Sherstobitova T. , Maryunina K. , Tolstikov S. , Letyagin G. , Romanenko G. , Nishihara S. , Inoue K.
Ligand Structure Effects on Molecular Assembly and Magnetic Properties of Copper(II) Complexes with 3-Pyridyl-Substituted Nitronyl Nitroxide Derivatives
ACS Omega. 2019. V.4. N17. P.17160-17170. DOI: 10.1021/acsomega.9b01575 WOS Scopus

Dates:

Published online:	Oct 7, 2019
Published print:	Oct 22, 2019

Identifiers:

Web of science:	WOS:000492429100010
Scopus:	2-s2.0-85073161667

Citing:

DB	Citing
Scopus	9
Web of science	11

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