Switchable Magnetic Materials Derived from Octacyanometallates

Abstract

Molecule-based magnetic materials encompass an advancing class of bistable materials that have garnered significant attention due to their intriguing physical properties and potential practical applications. These materials showcase distinctive properties including energy-efficient synthesis, solubility in typical organic solvents, suitability for device fabrication, tunable photo and thermochromic properties etc. Moreover, molecular magnetism provides the opportunity to design a wide variety of materials with varying dimensionalities, ranging from molecular zero-dimensional (0D) to three-dimensional (3D) networks with the potential application in areas such as information storage devices, molecular qubits, spintronics, quantum computing, nanotechnology, and many more. My thesis is focused mainly on the design and synthesis of multifunctional molecule-based magnetic materials exhibiting novel feature such as spin crossover (SCO), metal-to-metal electron transfer (MMET), and single-molecule magnet (SMMs) properties. Efforts were made to design materials of varying dimensionalities (0D, 1D, 2D, and 3D) by incorporating magnetic interactions between 3d and 4d/5d transition metal ions through cyanide bridges. Using complex as ligand strategy, a series of new multifunctional hetero-bimetallic W-Fe (square), Mo-Fe (3D-framework) , W-Mn (1D chain), W-Co (2D framework), Mo-Co (square), Mo-Cu (molecular and 3D systems), complexes have been designed. To gain a comprehensive understanding of SCO and MMET properties, including the impact of solvent, cooperativity, ligand field effect, etc., detailed studies have been conducted using various physical techniques such as magnetic, optical, spectroscopic, electrochemical, and X-ray fine structure characterizations. Notably, these complexes demonstrate diverse properties, including thermo- and photo-switching behaviour, photochromism, thermochromism, single-crystal to single-crystal transformation, magnetic ordering, and several interesting bistable properties. Finally, this work is summarised with a comprehensive summary that offers valuable insights for future advancements in multifunctional materials, contributing to the further enrichment of this research field.