Gaining a better understanding of the motion of large systems is one of the most engaging scientific challenges of our time. The increasing structural complexity of newly synthesized chemical compounds translates into their ability to generate more and more complex molecular motions. This is a consequence of the perpetual searching for novel materials for increasingly demanding applications. As an example, organic materials for organic light-emitting diodes (OLEDs) can be given. Inspired by nature, chemists have long been interested in the design and synthesis of artificial molecular systems capable of precise mechanical operation and energy transfer. The common feature of mentioned systems is the secret of their structural and dynamic complexity, hidden in objects of considerable size and directional properties. Such materials are a collection of rigid π-conjugated heterocyclic units connected in a way that ensures the optimal path for electron transport. Considering such systems from the point of view of the dynamics raises many fundamental questions about the influence of anisotropy and large size on their motion most of which have been never studied before. To explore them, we need extraordinary tools and pioneering solutions. Therefore, we have proposed a new concept of sizable glass-forming materials. The correlated dynamics of several moving parts within a single molecule make sizable systems a platform of materials providing an intriguing starting point for future studies of such intricate objects. Fluorene-based compounds combining different π-conjugated building blocks are attractive candidates for various light-emitting applications, e.g. in OLEDs. A growing interest in motion capture, soft robotics, and wearable medical technologies has stimulated interest in flexible electronic materials. Sizable glass-formers are a promising class of materials that can meet future soft-material requirements.