Oxalate-bridging NdIII-based arsenotungstate with multifunctional NIR-luminescence and magnetic properties. Issue 26 (24th June 2022)

• Record Type: Journal Article
• Authors: Chen, Hanhan; Sun, Lin; Zheng, Kangting; Zhang, Jinpeng; Ma, Pengtao; Wang, Jingping; Niu, Jingyang
• Is Part Of: Dalton transactions. Volume 51:Issue 26(2022)
• Page Start: 10257
• Page End: 10265
• Publication Date: 2022-06-24
• Subjects: Chemistry, Inorganic -- Periodicals; Chemistry, Physical and theoretical -- Periodicals; Chemistry, Inorganic -- Periodicals; 546.05
• DOI: 10.1039/d2dt01066f
• Languages: English
• ISSNs: 1477-9226

Abstract

Abstract : NIR luminescent oxalate-bridging Nd-based arsenotungstate exhibits field-induced single-molecule magnet behavior, and represents the third example of Nd-based POM SMMs. Abstract : Oxalate bridged Nd-based arsenotungstate, K14 Na6 H4 [{(As2 W19 O67 (H2 O))Nd(H2 O)2 }2 (C2 O4 )]·64H2 O (1 ), was obtained from the reaction of K14 [As2 W19 O67 (H2 O)], oxalic acid, and NdCl3 ·6H2 O in mildly acidic aqueous solution. The polyanion exhibits a dimeric structure in which the fully deprotonated oxalate ligands bridge two Nd III cations and the arsenotungstate anions act as blocking ligands. The photoluminescence (PL) spectrum of 1 shows the characteristic emission peak of Nd III in the near-infrared (NIR) region. However, the O → W charge-transfer transitions of arsenotungstate cannot effectively sensitize the emission of Nd III cations as confirmed by the emission spectrum, due to the mismatch of the energy gap between 3 T1u → 1 A1g (21.57 × 10 3 cm −1 ) of arsenotungstate components and 4 F3/2 → 4 I9/2 (11.43 × 10 3 cm −1 ) of Nd III cations. Magnetic studies of 1 demonstrate its field-induced single-molecule magnet (SMM) behavior. Direct current magnetic susceptibility studies imply the weak ferromagnetic couplings present between the two neighboring Nd III cations. In addition, the synergy between the coordination configuration of Nd III cations and the intramolecular magnetic interaction was discussed.