MS10-P06 Interactions studies in the crystal structures of Thiosemicarbazones and their Thiazol derivatives Doaa Ahmed Osman (Department of Physical and Analytical Chemistry, University of Oviedo, Oviedo, Spain) Mohammed S. M. Abdelbaky (Department of Physical and Analytical Chemistry, University of Oviedo, Oviedo, Spain) Rafael Mendoza-Meroño (Department of Physical and Analytical Chemistry, University of Oviedo, Oviedo, Spain) Santiago García-Granda (Department of Physical and Analytical Chemistry, University of Oviedo, Oviedo, Spain)email: doaaosman90@gmail.comThiosemicarbazone compounds have been the subject of intense research for the last twenty years due to their biological and medicinal properties (1). Other interesting application is the possibility of obtaining thiazoles derivatives from thiosemicarbazones using the Hantzsch Reaction; these compounds also present pharmaceutical and biological activities (2). Structurally thiosemicarbazones are versatile building blogs in the synthesis of densely sustituted blocks (3).
In this work we present the crystal structure of some thiosemicarbazones (figure-1a) and their thiazol derivatives (figure-1b), focusing in the study of the interactions that stabilize the crystal lattice.
In general, in the molecular crystals of thiosemicarbazones, hydrogen bonds interactions are established through –NH-C(S)-NH-N= fragment, forming in many cases synthons. Even though that C=S···H-N hydrogen bond is weaker than their C=O···H-N analogous, the effective electronegativity of S is increased by conjugative interactions between C=S and the lone pair of one or more N substituyents. This effect is called resonance-induced hydrogen bonding at Sulfur Acceptor (4). Due to the low solubility of thiosemicarbazones we use different mixtures of solvents in order to crystallize these compounds. For this reason is possible the inclusion of solvent molecules in the crystal lattice to form the corresponding solvates (5), in these cases we analyze the influence of the solvent in the synthons formation.
In thiazol compounds which contain halogen atoms (Cl) and phenyl groups, C-H···Cl and π-π stacking interactions have been also studied.
References:

[1] C.Shuhong, C. Xiahui, C. Ligen, C. Jingwen. Anti-Cancer Agents In Medicinal Chemistry. 2016, 16, 973-991.

[2] M.E.Khalifa. Acta Chimica Slovenica. 2018, 65, 1-22.

[3] S.Cunha, T.Lima da Silva. Tetrahedron. 2009, 18, 2090-2093

[4] F.H.Allen, C.M.Bird, R. S. Rowland, P.R. Raithby. Acta Cryst. 1997, B53, 680-695.

[5] R. Mendoza-Meroño, L. Menéndez-Taboada, E. Fernández-Zapico, S. García-Granda. Acta Crys. 2010, E66, o1029

Keywords: Thiosemicarbazones, Thiazols, Weak interactions