A New Family of <scp>SO<sub>4</sub><sup>2</sup></scp><sup>–</sup>‐Templated 3d‐4f High‐Nuclearity Clusters: Syntheses, Structures, and Magnetic Properties<sup>†</sup>
Cai-Hong Fan, Kai‐Peng Bai, Qian‐Cheng Luo, Tian Han, Chang Huang, Yanzhen Zheng, Weipeng Chen
Abstract
Comprehensive Summary The precise syntheses of transition–rare‐earth metal clusters with desired structures remain a great challenge. Herein, by utilizing SO 4 2– anion released by in‐situ decomposition of sodium dodecyl sulfate (SDS) as a template, a series of novel high‐nuclearity 3d‐4f clusters, formulated as [Ni 24 Pr 22 (μ 3 ‐OH) 31 (pida) 24 (SO 4 ) 4 (NO 3 ) 9 (CH 3 COO) 3 ]·Br 4 ·(NO 3 ) 11 ·16H 2 O·25CH 3 OH ( 1 , H 2 pida = N ‐phenyliminodiacetic acid), [Ni 24 Nd 22 (μ 3 ‐OH) 31 (pida) 24 (SO 4 ) 4 (NO 3 ) 9 (CH 3 COO) 3 ]·Br 4 ·(NO 3 ) 11 ·14H 2 O·24CH 3 OH ( 2 ) and [Ni 24 Gd 22 (μ 3 ‐OH) 36 (bida) 24 (SO 4 ) 7 (NO 3 ) 3 (CH 3 COO) 3 ]·(SO 4 )·Br 4 ·(NO 3 ) 4 ·31H 2 O·32CH 3 OH ( 3 , H 2 bida = N ‐benzyliminodiacetic acid), have been successfully isolated. X‐ray crystal structure analyses reveal that all the cationic {Ni 24 RE 22 } cores in 1 — 3 possess a ball‐like structure with C 3 v symmetry, and can be viewed as consisting of an inner {RE 22 } core and an outer {Ni 24 } shell. From 1 and 2 to 3 , due to the lanthanide contraction effect, the coordination numbers for rare‐earth metal centers in {RE 22 } are different, resulting in different number of SO 4 2– and NO 3 – anions to support and stabilize the skeleton structures. Meanwhile, the magnetic properties of complexes 1 — 3 were also studied. The result revealed that complexes 1 — 3 show antiferromagnetic/ferrimagnetic interactions, and 3 exhibits magneto‐caloric effect at ultralow temperatures with a maximum –Δ S m (magnetic entropy change) value of 33.03 J·kg −1 ·K −1 at 3.0 K and 7 T.