Molecular systems are ideal platforms for future quantum technologies because molecules can be fine-tuned by synthetic chemistry to provide atomic precision, tunability, and reproducibility. Molecules possess electronic and nuclear degrees of freedom that provide a wide range of transition energies across optical, infrared, and microwave frequencies. In this thesis, I present my studies of the physical and electronic structures of lanthanide organometallic complexes and transition metal chalcogenide nanoplatelets. First, I present my investigation into the spectral properties of Yb(III) complexes, which exhibit an ultra-narrow absorption linewidth in solution at room temperature. The ultra-narrow absorption offers unique applications in magnetic sensing. I demonstrate three different magnetometry techniques that we developed, based on magnetic circular dichroism of the narrow absorption feature. Secondly, I discuss the photophysical properties of highly bound and mobile excitons in colloidal nanoplatelets, which have atomically precise monolayer thicknesses that can be easily tuned for specific absorption and emission properties. I utilize two concepts (the Elliott model and dielectric screening) commonly applied to 2D materials to investigate the absorption of cadmium and mercury chalcogenide nanoplatelets, reporting exciton binding energies for several nanoplatelets for the first time. The investigations highlighted in these chapters emphasize the importance of chemistry in the rational design of quantum technologies. The last chapter depicts the chemical education research conducted in the remote implementation of general and organic chemistry courses during the COVID-19 pandemic, emphasizing the importance of providing structure to online discussion sections to increase student engagement.