Magnetic Properties and Second Harmonic Generation of Noncentrosymmetric Cyanido-Bridged Ln(III)–W(V) Assemblies

Abstract

One-dimensional zigzag cyanido-bridged coordination polymers have been prepared as a result of self-assembly of lanthanide­(III) ions with octacyanidotungstate­(V) anions in the presence of N,N-dimethylacetamide (dma). All compounds crystallized in noncentrosymmetric space group P21 with a molecular formula of [LnIII(dma)5]­[WV(CN)8] [Ln = Gd (1), Tb (2), Dy (3), Ho (4), Er (5), Tm (6), Yb (7), Lu (8), or Y (9)]. Magnetic studies revealed weak antiferromagnetic interactions through LnIII–NC–WV bridges and the formation of ferrimagnetically coupled chains at very low temperatures. Moreover, temperature dependencies of magnetic susceptibilities were fitted using the crystal field parameters for Ln­(III) ions, determined by the ab initio calculations, yielding magnetic coupling constants in the range of −1 to −5 cm–1. The wide optical transparency of 1–9 has been determined using solid state absorption spectroscopy. Samples exhibited second harmonic (SH) generation properties with SH susceptibilities ranging from 4.7 × 10–12 to 9.4 × 10–11 esu due to the presence of nonlinear optical susceptibility tensor elements (χ ijk ) χ zxx , χ zyy , χ zzz , χ zxy , χ yyz , χ yzx , χ xyz , and χ xzx , corresponding to space group P21. The determined values were also compared with the results of theoretical calculations and previous reports, indicating a potential relationship between the type of lanthanide ion and the SH intensity.

Tetraanionicarachno‐Carboranyl Ligand Imparts Strong Axiality to Terbium(III) Single‐Molecule Magnets

“…They are mirror‐symmetry related structures (Figure S2). Similar results can also be found in other lanthanide analogues [43] …”

“…Similar results can also be found in other lanthanide analogues. [43] To check the crystal field effect of such a hexagonalprismatic geometry we performed ab initio calculations at the SA-CASSCF/RASSI level [44a] for 2Dy, 2Tb, 2Ho and 2Er (see Supporting Information for details) and a recently proposed method to determine the theoretical energy barrier was utilized. [44b] The electronic structure of 2Tb gives a high axiality of the ground pseudo-doublet with a tunnel splitting gap (Δ tun ) of 0.0005 cm À 1 (Figure S51) and g z value of 17.94, which is close to that for the pure m J = � 6 state (Table S4).…”

Nonlinear Optical and Magnetic Properties of FeII-SCN-HgII Isomers: Centrosymmetric Layers and Chiral Networks

“…They also have a similar orientation, bearing in mind that the DFT calculations are based on a simplified structural model due to structural complexity and computational constraints. This result implies that the electric polarization vector, as well as the SHG strength of such complexes, can be tuned by applying more polar analogues of 2-acpy. , …”

“…This result implies that the electric polarization vector, as well as the SHG strength of such complexes, can be tuned by applying more polar analogues of 2-acpy. 87,88 Magnetic Properties. The magnetic properties of 1 and 2 were investigated by measuring the thermal dependence of the product of magnetic susceptibility (χ M ) and temperature per iron(II) center in the external magnetic field H dc = 1 kOe and the external magnetic field dependence of magnetization (M) at 2 K (Figure 5).…”

Tetraanionic arachno-Carboranyl Ligand Imparts Strong Axiality to Terbium(III) Single-Molecule Magnets

“…Similar results can be also found in other lanthanide analogues. [42] Figure 2 The ab initio calculated electronic states. Comparison of ab initio calculated electronic states of [Ln(R-C2B10H10)2] 5− (Ln = Tb, Dy, Ho, Er).…”