N3O6 versus N2O6 coordinated dysprosium slow magnetic relaxation in a tetrathiafulvalene-based dinuclear complex

Abstract

The reaction between the 2-(1-(4'-[4-(methylphenyl]-2,2:6',2''-terpyridyl)-4,5-(4,5bis(propylthio)-tetrathiafulvalenyl)-1H-benzimidazol-2-yl)-pyridine (L) and 2 equivalents of Dy(hfac) 3 2H 2 O (hfac-= 1,1,1,5,5,5-hexafluoroacetyacetonate) metallic precursors leads to the formation of a dinuclear complex of formula [Dy 2 (hfac) 6 (L)]C 6 H 14 (Dy2). The X-ray structure on single crystal reveals the occupation of the two benzoimidazolylpyridine (bzip) and terpyridyl (terpy) coordination sites with a Dy(III) ion. The two D 4d and C 4v Dy(III) ions highlighted slow magnetic relaxation under an applied magnetic field. Even if the two lanthanide centers have similar magnetic anisotropy, they displayed different relaxation times of their magnetization which could be explained by the distinct nature of the magnetic relaxation processes. These conclusions are supported by ab initio calculations.

In situ hydrolysis of a carbophosphazene ligand leads to one-dimensional lanthanide coordination polymers. Synthesis, structure and dynamic magnetic studies

“…The presence of multiple out-of-phase magnetic susceptibility contributions could be attributed to Ln(III) ions in different coordination environments 74,75 crystallographically independent Ln III ions, 76 or to the presence of significant dipolar interaction. 77 The latter origin could be discarded because the ac magnetic susceptibility was carried out under an applied dc field.…”

Decorated Tetrathiafulvalene‐Based Ligands: Powerful Chemical Tools for the Design of Single‐Molecule Magnets

“…with the 2,6-di(pyrazol-1-yl)-4-(bromomethyl)pyridine [138,139] and 4'-[4-(bromomethyl)phenyl]-2,2:6',2"-terpyridine [140] using similar procedure than for L 4 . Once they reacted with two equivalents of Dy(hfac)32H2O precursors, dinuclear complexes were obtained and isolated as single crystals with the formula [Dy2(hfac)6(L 5 )](CH2Cl2)2C6H14 ( 7) [141] and [Dy2(hfac)6(L6)]C6H14 (8) [142] (Figure 12). The two structures confirmed that the two bis-and trischelating coordination sites are occupied by the Dy(hfac)3 moieties with distinct coordination sphere symmetry.…”

Decorated Tetrathiafulvalene‐Based Ligands: Powerful Chemical Tools for the Design of Single‐Molecule Magnets

“…The ligands 2‐(1‐(2,6‐di(pyrazol‐1‐yl)‐4‐methylpyridyl)‐4,5‐(4,5‐bis(propylthio)‐tetrathiafulvalenyl)‐1H‐benzimidazol‐2‐yl)‐pyridine ( L 5 ) and 2‐(1‐(4′‐[4‐(methylphenyl)]‐2,2:6′,2′′‐terpyridyl)‐4,5‐(4,5‐bis(propylthio)‐tetrathiafulvalenyl)‐1H‐benzimidazol‐2‐yl)‐pyridine ( L 6 ) (Scheme ) were obtained by alkylation of L 1 with the 2,6‐di(pyrazol‐1‐yl)‐4‐(bromomethyl)pyridine, and 4′‐[4‐(bromomethyl)phenyl]‐2,2:6′,2′′‐terpyridine using similar procedure than for L 4 . Once they reacted with two equivalents of Dy(hfac) 3 · 2H 2 O precursors, dinuclear complexes were obtained and isolated as single crystals with the formula [Dy 2 (hfac) 6 ( L 5 )] · (CH 2 Cl 2 ) 2 · C 6 H 14 ( 7 ) and [Dy 2 (hfac) 6 (L 6 )] · C 6 H 14 ( 8 ) (Figure ).…”

“…Color code: carbon: gray, nitrogen: blue, oxygen: red, sulfur: yellow, fluoride: light green and dysprosium: light blue. Adapted from refs , …”

“…(b) Orientation of the computed ground state g‐tensor main component (g z ) and projection of the molecular electrostatic potential on the eight coordinated Dy(III) (left, blue line) and nine coordinated Dy(III) (right, green line) centers. Adapted from ref …”