Oligopeptides are well known for their self-assembling ability and application in the nanomaterials industry [1]. The variety of self-assembled nanostructures opens up a wide range of applications in biosensors, organic semiconductors, and drug delivery [2-4]. Their supramolecular structure and chirality depend on monomers' absolute configuration (AC) [5]. It has been shown that some oligopeptides undergo cyclization under heat treatment [6]. The linear dipeptide (L)Leu-(L)Leu is one such example [7].

In this talk, I will present a comprehensive spectroscopic characterization of the cyclo Leu-Leu solid-state synthesis, see Figure. It will be divided into three parts. First, I will discuss the role of packing in the synthesis using transient absorption IR spectroscopy on the time scale of seconds. The second part will be devoted to investigating morphological changes using optical and Raman microscopy. Finally, I will conclude by evaluating the conservation of the absolute configuration of the residues using vibrational circular dichroism and nuclear magnetic resonance.