Magnetic Cationic Copper(II) Chains and a Mononuclear Cobalt(II) Complex Containing [Ln(hfac)(4)](-) Blocks as Counterions

Author(s):Show less -

de Souza, Mateus S. ^[1] ; Briganti, Matteo ^{[2, 3]} ; Reis, Samira G. ^[1] ; Stinghen, Danilo ^[1] ; Bortolot, Carolina S. ^[1] ; Cassaro, Rafael A. A. ^[4] ; Guedes, Guilherme P. ^[1] ; da Silva, Fernando C. ^[1] ; Ferreira, Vitor F. ^[1] ; Novak, Miguel A. ^[5] ; Soriano, Stephane ^[6] ; Totti, Federico ^{[2, 3]} ; Vaz, Maria G. F. ^[1]

Affiliation

^[1] Univ Fed Fluminense, Inst Quim, BR-24020150 Niteroi, RJ - Brazil

^[2] Univ Florence, Dept Chem Ugo Schiff, I-50019 Sesto Fiorentino - Italy

^[3] Univ Florence, INSTM RU, I-50019 Sesto Fiorentino - Italy

^[4] Univ Fed Rio de Janeiro, Inst Quim, BR-21941909 Rio De Janeiro - Brazil

^[5] Univ Fed Rio de Janeiro, Inst Fis, BR-21941972 Rio De Janeiro - Brazil

^[6] Univ Fed Fluminense, Inst Fis, BR-24020140 Niteroi, RJ - Brazil

• Document type: Journal article
• Source: Inorganic Chemistry; v. 58, n. 3, p. 1976-1987, FEB 4 2019.
• Web of Science Citations: 8

Abstract

Four new heterospin compounds with molecular formula [{[}Cu-2(hfac)(3)(TlTrzNIT)(2)]{[}Ln(hfac)(4)]](n)center dot C7H16 (Ln(III) = Gd (1), Tb (2), or Dy (3)) and {[}Co(hfac)(TlTrzNIT)(2)] {[}Dy(hfac)(4)] (4), where hfac is hexafluoroacetylacetonato and TlTrzNIT is the nitronylnitroxide radical 1-(m-tolyl)-1H-1,2,3-triazole-4-(4,4,5,5-tetramethylimidazoline-1-oxyl-3 -oxide), were obtained. All structures were determined by single-crystal X-ray diffraction. In compounds 1-3, the TlTrzNIT radical is bridge-coordinated to copper(II) ions, leading to positively charged copper(II)-radical chains containing {[}Ln(hfac)(4)](-) as counterions. In compound 4, the cobalt(II) ion is coordinated to two TlTrzNIT radicals and one hfac ligand in bidentate mode leading to a mononuclear cationic complex that contains {[}Dy(hfac)(4)](-) as counterion. Magnetic measurements of all complexes were performed. Magnetic data were fit considering the contributions of the copper(II)-radical chain and a paramagnetic gadolinium(III) ion for 1. The sign and magnitude of the magnetic coupling constants extracted from the fit were confirmed by density functional theory calculations. The obtained spin topology shows an alternated ferro-antiferromagnetic chain. Field-induced single molecule magnet behavior was observed for the Dy derivatives 3 and 4, in agreement with CASSCF calculations performed for the latter system. (AU)

• FAPESP's process: 09/54082-2 - Acquisition of a vibranting sample magnetometer coupled with a superconducting quantum interference device assensor (Squid-VSM) with cryogenic closed cycle
• Grantee: Ernesto Chaves Pereira de Souza
• Support Opportunities: Multi-user Equipment Program