24 March 2022

Séminaire ICP – Ariel Perez Mellor – jeudi 24 mars à 14h

Séminaire de Ariel Francis Perez Mellor (University of Geneva)

Le jeudi 24 mars à 14h - salle Magat et session Zoom

"Solid-State Synthesis of cyclo Leu-Leu: A Comprehensive Spectroscopic Study"

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

This seminar 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 polymorphisms in the synthesis using transient absorption IR spectroscopy on the time scale of seconds. The second part will be dedicated to investigating morphological changes using optical and Raman microscopy. Finally, I will conclude by evaluating the conservation of chirality using vibrational circular dichroism.

Figure : Scheme of the cyclization reaction for the four stereoisomers assuming the conservation of the AC of the residue. The notation z stands for zwitter ionic form and c stands for cyclic form.

[1] Manchineella S, et al. Chempluschem (2017): 88-106.

[2] Joon Seok Lee, et al. Angewandte Chemie Int Ed. (2011): 1196-1199.

[3] Rondes F. Silva, et al. Langmuir (2013): 10205-10212.

[4] S. Kogikoski, et al. Phys Chem Chem Phys (2016): 3223-3233.

[5] Gorbitz, et al. Chem. Eur. J. (2001): 5153-5159.

[6] Ziganshin, M.A, et al. J Therm Anal Calorim (2016).

[7] Marat A. Ziganshin, et al. J. Phys. Chem. B (2017).

 

24 March 2022, 14h0015h00
salle Magat - session hybride