Quantum computers provide a powerful resource to push the boundaries of current knowledge. At the core of their logical architecture are quantum bits and quantum logic gates. Electron spin can be used as a resource to encode logical operators, and, as such, magnetic molecules have proven to be a versatile platform for the realization of fundamental logical units. They offer the possibility of finely tuning desired quantum properties by exploiting targeted chemical approaches. This thesis book provides fundamental knowledge about quantum logical units, with a focus on magnetic molecules and electron spin dynamics. It reports on the various chemical approaches employed to advance beyond the current state-of-the-art in electron spin-based molecular quantum technologies.