Details

Autor(en) / Beteiligte

• de Campos, Nathália R
• Simosono, Cintia A
• Landre Rosa, Iara M
• da Silva, Rafaela M. R
• Doriguetto, Antônio C
• do Pim, Walace D
• Gomes Simões, Tatiana R
• Valdo, Ana Karoline S. M
• Martins, Felipe T
• Sarmiento, Charlie V
• Nunes, Wallace C
• Guedes, Guilherme P
• Pedroso, Emerson F
• Pereira, Cynthia L. M
• Stumpf, Humberto O
• Lloret, Francesc
• Julve, Miguel
• Marinho, Maria Vanda

Titel

Building-up host-guest helicate motifs and chains: a magneto-structural study of new field-induced cobalt-based single-ion magnets

Ist Teil von

• Dalton transactions : an international journal of inorganic chemistry, 2021-08, Vol.5 (31), p.177-1728

Ort / Verlag

Cambridge: Royal Society of Chemistry

Erscheinungsjahr

2021

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• In this work, we present the synthetic pathway, a refined structural description, complete solid-state characterization and the magnetic properties of four new cobalt( ii ) compounds of formulas [Co(H 2 O) 6 ][Co 2 (H 2 mpba) 3 ]·2H 2 O·0.5dmso ( 1 ), [Co(H 2 O) 6 ][Co 2 (H 2 mpba) 3 ]·3H 2 O·0.5dpss ( 2 ), [Co 2 (H 2 mpba) 2 (H 2 O) 4 ] n ·4 n H 2 O ( 3 ), and [Co 2 (H 2 mpba) 2 (CH 3 OH) 2 (H 2 O) 2 ] n ·0.5 n H 2 O·2 n dpss ( 4 ) [dpss = 2,2′-dipyridyldisulfide and H 4 mpba = 1,3-phenylenebis(oxamic) acid], where 2 and 4 were obtained from [Co(dpss)Cl 2 ] ( Pre-I ) as the source of cobalt( ii ). All four compounds are air-stable and were prepared under ambient conditions. 1 and 2 were obtained from a slow diffusion method [cobalt( ii ) : H 2 mpba 2− molar ratio used 1 : 1] and their structures are made up of [Co 2 (H 2 mpba) 3 ] 2− anionic helicate units and [Co(H 2 O) 6 ] 2+ cations, exhibiting supramolecular three-dimensional structures. Interestingly, a supramolecular honeycomb network between the helicate units interacting with each other through R 2 2 (10) type hydrogen bonds occurs in 2 hosting one co-crystallized dpss molecule. On the other hand, for the first time, linear ( 3 ) and zigzag ( 4 ) cobalt( ii ) chains were isolated by slow evaporation of stirred solutions of mixed solvents with cobalt( ii ) : H 2 mpba 2− in 1 : 2 molar ratio at room temperature. Magnetic measurements of Pre-I revealed a quasi magnetically isolated S = 3/2 spin state with a significant second-order spin-orbit contribution as expected for tetrahedrally coordinated cobalt( ii ) ions. The analysis of the variable temperature static (dc) magnetic susceptibility data through first- ( 1 and 3 ) and second-order spin-orbit coupling models ( 2 and 4 ) reveals the presence of magnetically non-interacting high-spin cobalt( ii ) ions with easy-axis ( 1 and 4 )/easy-plane magnetic anisotropies ( 2 and 4 ) with low rhombic distortions. Dynamic (ac) magnetic measurements for Pre-I and 1-4 below 8.0 K show that they are examples of field-induced Single-Ion Magnets (SIMs). The slow diffusion method affords host-guest systems ( 1 and 2 ), while the stirring method results in chains ( 3 and 4 ) that behave as field-induced cobalt-based Single-Ion Magnets (SIMs).