A series of zero-dimensional Co(II)-Ln(III) heterometallic complexes derived from 2,3-dichlorobenzoate and 2,2′-bipyridine: Syntheses, structures and magnetic properties

Synthesis, structure, photoluminescence and magnetism of a series of cobalt‐lanthanide heterometallic complexes originated from 2,3‐dichlorobenzoate and 1,10‐phenanthroline

“…Complexes 4 and 6 show similar 2D supramolecular structures to that of 1 (Figure 2). The crystal structures of 1-7 are similar to those of [Ln 2 Co 2 (2,3-DCB) 10 (2,2'-bpy) 2 ] (Ln=Nd, Sm, Eu, Gd, Tb, Dy, Er), [26] but different from those of [Dy 2 Co 2 (PhCOO) 10 (phen) 2 ] (PhCOOH = benzoic acid), [Dy 2 Co 2 (NO 2 -PhCOO) 10 (phen) 2 ] (NO 2 -PhCOOH = 3-nitrobenzoic acid) [27] and [Dy 2 Co 2 L 10 (phen) 2 ] (HL = 4-triflfluoromethylbenzoic acid). [28] This indicates that the type and position of the substituent groups of benzoate play an important role in the formation of these complexes, whereas the co-ligands have a slight effect.…”

“…As a result, the effective energy barrier and relaxation time cannot be obtained by fitting the Arrhenius law. Considering that there is only one type of Dy(III) environment in 6, corresponding to one relaxation process, the effective energy barrier and relaxation time can be extracted from the out-ofphase (χ'') AC data above 100 Hz under 2000 Oe DC field by fitting the Debye model ln(χ''/χ') = ln(ωτ 0 ) + E a /k B T (Figure 7), [46] namely E a /k B � 10 K and τ 0 � 6×10 À 6 s. The AC magnetic properties of 6 are similar to those of [Dy 2 Co 2 (2,3-DCB) 10 (2,2'-bpy) 2 ], [26] [Dy 2 Co 2 (PhCOO) 10 (phen) 2 ] (PhCOOH = benzoic acid), [Dy 2 Co 2 (NO 2 -PhCOO) 10 (phen) 2 ] (NO 2 -PhCOOH = 3-nitrobenzoic acid) [27] and [Dy 2 Co 2 L 10 (phen) 2 ] (HL = 4-triflfluoromethylbenzoic acid). [28] Figure 5.…”