Modulating Two Pairs of Chiral Dy^III Enantiomers by Distinct β-Diketone Ligands to Show Giant Differences in Single-Ion Magnet Performance and Nonlinear Optical Response

Abstract

Using Dy­(dbm)3(H2O) and Dy­(btfa)3(H2O)2 to react with enantiopure N-donors, (−)/(+)-4,5-pinenepyridyl-2-pyrazine (L R /L S ), respectively, two pairs of chiral DyIII enantiomers, Dy­(dbm)3L R /Dy­(dbm)3L S ( R-1-Dy/ S-1-Dy) and Dy­(btfa)3L R /Dy­(btfa)3L S ( R-2-Dy/ S-2-Dy) were obtained, wherein one of the benzene rings of dbm– (dibenzoylmethanate) in R-1-Dy/ S-1-Dy is displaced by the −CF3 group of btfa– (4,4,4-trifluoro-1-phenyl-1,3-butanedionate) in R-2-Dy/ S-2-Dy. Interestingly, this substitution results not only in giant differences in their single-ion magnetic (SIM) performances but also in their completely different nonlinear optical (NLO) responses. R-1-Dy presents a large effective energy barrier (U eff = 265.47 K) under zero applied field, being more than 4 × R-2-Dy (61.40 K). The discrepancy on their magnetic performances has been further elucidated by ab initio calculations. Meanwhile, R-1-Dy/S-1-Dy display the strongest third-harmonic generation responses (35/33 × α-SiO2) among the known lanthanide NLO-active coordination compounds (CCs). On the contrary, R-2-Dy/S-2-Dy exhibit moderate second-harmonic generation responses (0.65/0.70 × KDP). These results not only give the first example of the CCs with both SMM/SIM behavior and a THG response but also provide an efficient strategy for achieving the function regulation and switch in multifunctional CCs.

Effects of Counterions, Coordination Anions, and Coordination Solvent Molecules on Single-Molecule Magnetic Behaviors and Nonlinear Optical Properties of Chiral Zn2Dy Schiff Base Complexes

“…All of these chiral compounds have stronger THG intensities than the reference α-SiO 2 . The χ R (3) values of these chiral complexes could be calculated according to eq with a χ R (3) value of 214 pm 2 V –2 for α-SiO 2 (Table ). χ S false( 3 false) = χ R false( 3 false) true( I S THG I R THG true) 1 / 2 The THG intensities of R - 2 (821 pm 2 V –2 ) and R- 3 (848 pm 2 V –2 ) are stronger than those of Dy III -β-diketonate isomers with nine-coordinated low symmetries too (770 and 706 pm 2 V –2 ) .…”

“…Therefore, the heavier bromide anion is more favorable for the SHG properties than the chloride anion when acting as a ligand to the zinc(II) ion. Based on the χ R (2) value of 0.39 pm V –1 for KDP and eq , the χ R (2) values of these chiral complexes could be calculated, as shown in Table . Notably, the SHG intensities of S - 1 and S- 3 (1.0 × KDP) are clearly stronger than those of chiral Zn(II)–Yb(III) enantiomers (0.2 × KDP) with the same chiral Schiff base ligands …”

“…All of these chiral compounds have stronger THG intensities than the reference α-SiO 2 . The χ R (3) values of these chiral complexes could be calculated according to eq 2 76 with a χ R…”

“…Therefore, the heavier bromide anion is more favorable for the SHG properties than the chloride anion when acting as a ligand to the zinc(II) ion. Based on the χ R (2) value of 0.39 pm V −1 for KDP 75 and eq 1, 76 the χ R (2) values of these chiral complexes could be calculated, as shown in Table 2 The SHG signal intensity of the corresponding R-configuration complexes follows the same rule (Figure 12b); that is, the isolated perchlorate anion favors the SHG properties over the isolated triflate anion, and the heavier coordination bromide anion is more favorable for the SHG properties than the coordination chloride anion. When sorted by the SHG signal strength from strong to weak, the result is R-3 greater than R-1 greater than R-2 (Table 2).…”

Two-dimensional dysprosium(III) coordination polymer: Structure, single-molecule magnetic behavior, proton conduction, and luminescence

“…As we know, the magnetic anisotropy of metal ions plays a very important role in the construction of SMMs ( Woodruff et al, 2013 ; Zhu et al, 2021 ). In this regard, lanthanide Dy(III) ion, may carry significant anisotropy because of its intrinsically large and unquenched orbital contribution to the magnetic moment ( Ding et al, 2018 ; Parmar et al, 2021 ; Li et al, 2022 ). Goodwin and co-workers made a breakthrough in Dy(III)-based SMMs, reporting compound that exhibits a high effective energy barrier of 1,760 K ( Goodwin et al, 2017 ).…”