Trinuclear Lanthanide Coordination Clusters: Single‐Molecule‐Magnet Behavior and Catalytic Activity in the Friedel‐Crafts Alkylation Reaction

Abstract

A new multidentate ligand (H3L) was synthesized by the condensation reaction of 4‐tert‐butyl‐2,6‐diformylphenol and 2‐amino‐4‐nitrophenol. The reaction of the ligand with hydrated lanthanide nitrate produced two isostructural trinuclear coordination clusters: [DyLn3L3(DMF)3(H2O)2] ⋅ 3.8DMFLn=Dy (1) and Nd (2) (DMF=N, N‐dimethylformamide). Single‐crystal X‐ray diffraction analysis revealed that there are three lanthanide ions arranged in an almost perfect linear fashion in both complexes. Magnetic studies show single‐molecule‐magnet (SMM) behavior in the Dy derivative with τ0=1.7×10−6 s and a thermal energy barrier of 7.0 cm−1. Both complexes were used as catalysts towards the Friedel‐Crafts alkylation reaction of indole with different aldehydes with yields varying from 59–98 %. Complex 1 showed better catalytic efficiency than complex 2. This is the first report of using trinuclear lanthanide coordination clusters as catalysts for the Friedel‐Crafts alkylation reaction.

Bis(catecholato)germane: an effective catalyst for Friedel–Crafts alkylation reaction

“…The isolated pure product was confirmed by NMR spectroscopy and mass spectrometry (see the ESI†) and verified with the reported data. 41–44…”

“…The isolated pure product was confirmed by NMR spectroscopy and mass spectrometry (see the ESI †) and verified with the reported data. [41][42][43][44] General procedure for the syntheses of nitroalkylated indoles β-Nitrostyrene (0.40 mmol) and indole (0.40 mmol) were added to a mixture of ethanol/water solvent mixture (2 : 1 v/v, 6 mL) followed by the addition of the complex 1 (0.040 mmol). The resulting clear solution was stirred at room temperature for 24 h. The progress of the reaction was checked by TLC.…”

The Potential of Gadolinium Ascorbate Nanoparticles as a Safer Contrast Agent

“…24,25 These clusters, in which the metals are connected through metallic bonding or bridging ligands, can behave as a single molecule exhibiting optical, 32−37 magnetic, 31,33,38,39 and catalytic properties. 40,41 Among different lanthanides, Gd-based clusters are promising as single molecular magnets, 29 as MRI contrast agents 24,25 or as industrial coolants with high magnetocaloric effect. 30,31,41−43 Synthesis of multinuclear Gd clusters requires skillful selection and manipulation of, coordinating ligands, bridging ligands, and the solvent.…”

A pentanuclear Er (III) coordination cluster as a catalyst for selective synthesis of 1,2‐disubstituted benzimidazoles

“…Recently, for the first time, we have introduced lanthanide coordination clusters containing three Dy (III) or Nd (III) ions for Friedel crafts alkylation reaction of indole. [10] In 2020, Findlater et al [11] used lanthanide coordination clusters for the hydroboration of esters and amides. In the present work, we are interested in exploring the catalytic activity of a lanthanide coordination cluster in the synthesis of benzimidazoles.…”