Synergistic Experimental and Theoretical Studies of Luminescent-Magnetic Ln 2 Zn 6 Clusters.
Sayan SahaKrishna Sundar DasTanu SharmaSukhen BalaAmit AdhikaryGuo-Zhang HuangMing-Liang TongArjit GhoshBenu Brata DasGopalan RajaramanRaju MondalPublished in: Inorganic chemistry (2022)
The present work is part of our ongoing quest for developing functional inorganic complexes using unorthodox pyridyl-pyrazolyl-based ligands. Accordingly, we report herein the synthesis, characterization, and luminescence and magnetic properties of four 3d-4f mixed-metal complexes with a general core of Ln 2 Zn 6 (Ln = Dy, Gd, Tb, and Eu). In stark contrast to the popular wisdom of using a compartmental ligand with separate islands of hard and soft coordinating sites for selective coordination, we have vindicated our approach of using a ligand with overcrowded N-coordinating sites that show equal efficiency with both 4f and 3d metals toward multinuclear cage-cluster formation. The encouraging red and green photolumiscent features of noncytotoxic Eu 2 Zn 6 and Tb 2 Zn 6 complexes along with their existence in nanoscale dimension have been exploited with live-cell confocal microscopy imaging of human breast adenocarcinoma (MCF7) cells. The magnetic features of the Dy 2 Zn 6 complex confirm the single-molecule-magnet behavior with befitting frequency- and temperature-dependent out-of-phase signals along with an U eff value of ∼5 K and a relaxation time of 8.52 × 10 -6 s. The Gd 2 Zn 6 complex, on the other hand, shows cryogenic magnetic refrigeration with an entropy change of 11.25 J kg -1 K -1 at a magnetic field of 7 T and at 2 K. Another important aspect of this work reflects the excellent agreement between the experimental results and theoretical calculations. The theoretical studies carried out using the broken-symmetry density functional theory, ORCA suite of programs, and MOLCAS calculations using the complete-active-space self-consistent-field method show an excellent synergism with the experimentally measured magnetic and spectroscopic data.
Keyphrases
- single molecule
- density functional theory
- heavy metals
- molecularly imprinted
- molecular dynamics
- atomic force microscopy
- mycobacterium tuberculosis
- endothelial cells
- living cells
- induced apoptosis
- squamous cell carcinoma
- quantum dots
- molecular dynamics simulations
- oxidative stress
- high resolution
- magnetic resonance imaging
- risk assessment
- drug delivery
- signaling pathway
- deep learning
- computed tomography
- contrast enhanced
- big data
- mass spectrometry
- locally advanced
- rectal cancer