Stereo sensitivity of exchange interactions in NiII and CuII heterospin complexes with 5-formylpyrrolyl-substituted nitroxides

• Published in: Russian chemical bulletin Vol. 65; no. 3; pp. 666 - 674
• Main Authors: Zueva, E. M., Tretyakov, E. V., Fokin, S. V., Romanenko, G. V., Tkacheva, A. O., Bogomyakov, A. S., Petrova, O. V., Trofimov, B. A., Sagdeev, R. Z., Ovcharenko, V. I.
• Format: Journal Article
• Language: English
• Published: New York Springer US 01-03-2016; Springer Nature B.V
• Subjects: Chemical synthesis; Chemistry; Chemistry and Materials Science; Chemistry/Food Science; Copper; Ferromagnetism; Full Articles; Inorganic Chemistry; Ligands; Nickel; Organic Chemistry; Orientation effects; Solid phases; Substitutes; copper(II) complexes; X-ray diffraction; quantum chemical calculations; nickel(II) complexes; nitroxide radicals; pyrrole
• ISSN: 1066-5285; 1573-9171
• DOI: 10.1007/s11172-016-1353-8

5-Formylpyrrolyl-substituted nitronyl and imino nitroxide radicals HL
1
and HL
2
were synthesized. Their solid phases are formed by packing pairs of the molecules. In the {HL
1
...HL
1
} pairs, the dominant interaction is the ferromagnetic exchange with
J
/kB = 8.8 K (Hamiltonian
H
=
2
J
(
s
1
→
·
s
2
→
)
). The ferromagnetic exchange occurs also in the heterospin molecules [Ni(L
1
)
2
], [Cu(L
1
)
2
], and [Ni(L
2
)
2
(MeOH)
2
]. In the complexes [Ni(L
1
)
2
] and [Cu(L
1
)
2
], a small change in the mutual orientation of the coordinated ligands has a considerable effect on the value and the sign of the energy of exchange interactions between the unpaired electrons of the metal ion and paramagnetic ligands.