New Family of Heptanuclear Lanthanide {Ln₇} Clusters: Synthesis, Structure, and Magnetic Studies

Abstract

A new family of heptanuclear lanthanide complex [Ln7(L)2(LH)4(dbm)5(OH)2(CH3OH)4]⋅xCHCl3⋅yCH3OH⋅zH2O {Ln=TbIII (1), DyIII (2) and ErIII (3) and LH3=(E)‐2‐(hydroxymethyl)‐6‐(((2‐hydroxyphenyl) imino) methyl)‐4‐methylphenol} [in 1, x=6, y=3, z=3; in 2, x=5, y=1, z=6; and in 3, x=4, z=2] has been prepared in presence of lanthanide chloride(III) salts and β‐diketonate co‐ligand dibenzoylmethane (dbm). Single crystal XRD reveals heptanuclear ensemble formed by collective action of two fully deprotonated [L]3− ligands, four double deprotonated [LH]2−, two μ3‐OH− ligands, five anionic [dbm]− β‐diketonate co‐ligands and two terminal methanol solvent molecules. This heptanuclear unit comprises of two [Dy4(μ2‐O)5(μ3‐OH)]+6 core sharing a common metal vertex Dy1 through which centre of inversion has passed for overall molecule. All the complexes have been magnetically characterized and dynamic AC magnetic studies reveals slow relaxation of magnetism present in dysprosium analogue (2).

Effect of diamagnetic Zn(ii) ions on the SMM properties of a series of trinuclear ZnDy2 and tetranuclear Zn2Dy2 (LnIII = Dy, Tb, Gd) complexes: combined experimental and theoretical studies

“…A methanolic solution of 2-(hydroxymethyl)-6-carbaldehyde-4-methylphenol 49 was added to a stirring methanolic solution of 8-aminoquinoline. This solution was then refluxed for eight hours affording the ligand LH 2 in the form of a red precipitate which was filtered and washed with methanol.…”

An Insight into the Biological Properties of Imidazole‐Based Schiff Bases: A Review

“…The nitrogen atom of azomethine might be engaged with the formation of a hydrogen bond with active centers of cell constituents and which is the key for biological properties. [57,58] Aside from natural activities, Schiff bases are likewise utilized as catalysts, intermediates in organic synthesis, dyes, pigments, polymer stabilizers, [56] and corrosion inhibitors. [59] Schiff bases have acquired significance in biological, industrial, or analytical chemistry and are used as an intermediate for several organic reactions.…”

“…The molinspiration computations anticipated that Schiff bases 51, 52, and 53 had atomic hydrophobicity, conformational adaptability, great intestinal absorption, and bioactivity scores. The chloro, bromo, and nitro subbed imidazolyl azetidinones (54,55,56) and nitro subbed imidazolyl triazoles (57) showed promising antibacterial activity on B. subtilis while chloro and nitro subbed imidazolyl triazoles (57,58) showed powerful antifungal activity on A. niger. [126] The effect of the chaotropicity of the anion for nine imidazole primarily based ionic liquids (59) on their antimicrobial behavior was first investigated by Mester et al (2015) (Figure 28).…”

“…Schiff bases are organic compounds which widely used for their biological applications. The nitrogen atom of azomethine might be engaged with the formation of a hydrogen bond with active centers of cell constituents and which is the key for biological properties [57,58] . Aside from natural activities, Schiff bases are likewise utilized as catalysts, intermediates in organic synthesis, dyes, pigments, polymer stabilizers, [56] and corrosion inhibitors [59] …”

Mononuclear Lanthanide Complexes in Triangular Dodecahedron Geometry: Manifestation of Single Ion Magnet Behavior for DyIII Analogue

“…Much attention has recently been drawn to the lanthanide complexes because of their versatile applications in the field of catalysis, , photophysical properties, − and magnetic materials. − Magnetic materials consisting of transition metal (3d) and/or lanthanide (4f) ions have promising applications in terms of data storage, low temperature magnetic refrigerant, spintronics, etc. − Initially, the field was restricted in the synthesis of multinuclear complexes containing 3d, 3d/4f, and 4f metal ions for achieving the larger ground ( S ) in the aim for a high energy barrier [ U eff = | D | S 2 ] for spin reversal. − Later on, realizing the fact that anisotropy ( D ) is inversely proportional to the square of total spin ( S ) of the complex, the research direction was shifted toward the synthesis of a mononuclear single molecule magnet or single ion magnet (MSMM or SIM). − Another important phenomenon that boosted the field toward the MSMM is to rationalize the structure property relationship through theoretical calculations. − The correlation of the magnetic properties with the geometry in MSMM becomes simpler compared to the polynuclear complexes. − MSMMs particularly containing lanthanide ions have attained a special interest due to the strong spin–orbit coupling (SOC) for lanthanides that invoke a large magnetic anisotropy in lanthanide-based complexes. − The field was embarked by Ishikawa and co-workers through the complex (Bu 4 N)­[Ln­(Pc) 2 ] (Ln III = Tb and Dy; Pc = phthalocyaninato) in 2003 . Recent examples by Layfield and others have accelerated the quest for lanthanide based complexes as molecular magnets. , However, the ground state intrinsic quantum tunneling of magnetization (QTM) that shortcuts the path f...…”