Name: Ms. Mayurika Das

Title: Synthesis and Physicochemical Characterizations of Anisotropic Monometallic Complexes: A Building Block Approach for Designing Multifunctional Materials.

Date &Time : Wednesday, 24th April 2024 at 11.00 a.m.

Venue: Rajarshi Bhattacharya Memorial Lecture Hall, Chemical Sciences Building

Molecule-based magnetic materials have recently been a popular choice for generating multifunctional materials1. An inherent property in such systems is molecular bistability, which enables a system to interchange between two easily accessible states (spin or magnetic) through the controlled application of external stimuli.2Multifunctional magnetic materials3 have fascinating applications in information storage4, spintronics5, andquantum computing6.A suitable synthetic procedure for such molecular magnetic systems entails a so-called “bottom-up” building block approach, where anisotropic monometallic complexes function as the elementary unit.All these molecule-based magnetic materials exhibit several intriguing properties, such as Spin Crossover (SCO)7, Single Molecule Magnets (SMMs)8, Single Chain Magnets (SCMs), Magnetic Sponge, and Linkage Isomerism9 behavior.In my thesis, I first synthesized a series of macrocyclic porphyrin-based monometallic systems to look for the possibility of these molecules functioning as molecular magnets. Detailed spectroscopic, electrochemical, magnetic, and theoretical studies have been performed on these systems to clearly understand their feasibility as viable multifunctional molecular magnets. Following this, I have explored the molecular magnetic sponge-like behavior in a family of heterobimetallic cyano-bridged[CrMn] coordination networks, where adsorption and desorption of solvent molecules play a crucial role in the magnetic properties.10Next, photo- and thermo-induced spin crossover propertieshave been investigated in a few heterobimetallic cyano-bridged [Cr2Fe3] multifunctional molecular clusters where the linkage isomerism property has been simultaneously observed.11In the last part of my thesis, I have studied the effect of ligand field strength on the magnetic anisotropy and relaxation behavior in a series of mono- and dinuclear high-spin Co(II) complexes.Finally, I would like to use these highly anisotropic Co(II) metal complexes for the synthesis of SCMs.12 Thereafter, I would conclude my talk by giving an outlook on the probable applications of the above-mentioned systems in devices and catalysis.

Coronado, E., Molecular magnetism: from chemical design to spin control in molecules, materials and devices. Nature Reviews Materials 2020,5 (2), 87-104.
Kaushik, K.; Mehta, S.; Das, M.; Ghosh, S.; Kamilya, S.; Mondal, A., Stimuli-responsive magnetic materials: impact of spin and electronic modulation. Chemical Communications 2023,59 (88), 13107-13124.

Kahn, O.; Martinez, C. J., Spin-Transition Polymers: From Molecular Materials Toward Memory Devices. Science (New York, N.Y.) 1998,279 (5347), 44-48.

Cavallini, M.; Gomez-Segura, J.; Ruiz-Molina, D.; Massi, M.; Albonetti, C.; Rovira, C.; Veciana, J.; Biscarini, F., Magnetic Information Storage on Polymers by Using Patterned Single-Molecule Magnets. Angewandte Chemie International Edition 2005,44 (6), 888-892.

Bogani, L.; Wernsdorfer, W., Molecular spintronics using single-molecule magnets. Nature Materials 2008,7 (3), 179-186.

Leuenberger, M. N.; Loss, D., Quantum computing in molecular magnets. Nature 2001,410 (6830), 789-793.

Ghosh, S.; Bagchi, S.; Das, M.; Kamilya, S.; Mondal, A., Stepwise spin-state switching in a manganese(iii) complex. Dalton Transactions 2020,49 (42), 14776-14780.

Ghosh, S.; Kamilya, S.; Das, M.; Mehta, S.; Boulon, M.-E.; Nemec, I.; Rouzières, M.; Herchel, R.; Mondal, A., Effect of Coordination Geometry on Magnetic Properties in a Series of Cobalt(II) Complexes and Structural Transformation in Mother Liquor. Inorganic Chemistry 2020,59, 7067-7081.

Coronado, E.; Giménez-López, M. C.; Levchenko, G.; Romero, F. M.; García-Baonza, V.; Milner, A.; Paz-Pasternak, M., Pressure-Tuning of Magnetism and Linkage Isomerism in Iron(II) Hexacyanochromate. Journal of the American Chemical Society 2005,127 (13), 4580-4581.

Das, Met alManuscriptSubmitted.

Das, Met al ManuscriptSubmitted.

Das, Met al ManuscriptSubmitted.