Hard-soft nitrogen–sulfur chelating agents in particular Schiff bases derived from S-alkyl and S-aryl esters of dithiocarbazic acid and their transition metal complexes [1] have been the subject of considerable study because of their interesting physicochemical properties [2]. The New Schiff base S-ally-β-N-[(2-hydroxyphenyl)methylene] hyrazinecarbodithioate (1), was prepared by condensation of salicylaldehyde with S-allyldithiocarbazate in ethanol solution as a fluffy pale-yellow crystalline solid. The 1 can exhibit thione-thiol tautomer since they contain the thioamide, -NH-C(S)S- functional group (see Fig. 1) [3]. The 1 can act as a new bi- and tridentate (SN, SNO) ligands and react with transition metal salts to synthesis several complexes. One of these interesting complexes is [Co3(H-L)2(L)2].2C2H5OH (2). The compounds have been characterized by elemental analysis, IR and Uv/Vis spectroscopy. The compound 2 has been also characterized by single-crystal X-ray analysis (see Fig. 2). According to the results, it is interesting to note that 2 can be observed two nitrogen atoms which are engaged in two different covalent bonds with two adjacent cobalt atoms. The result X-ray-data of compound 2 shows two different geometries. The Central Co(II) atom, is bonded to two deprotonated ligands with distorted octahedral geometry. The corner cobalt(II) atoms are situated in the mean of SNON-coordination plane and have distorted square planar geometry with connected to the central one by N-atoms. The Hirshfeld surface [4] is becoming a valuable device for analyzing the intermolecular interactions while maintaining a whole-of-molecule approach. There are hydrogen-bonding interactions in the complex 2, because of the presence of N, O, S and H atoms in molecule structure. H•••H, C•••H, S•••H, N•••H, H•••N, O•••H, H•••O, H•••C and H•••S have been observed in the crystal lattice and the relative contributions to the Hirshfeld surface area shows (Fig. 3). In this work, we have demonstrated how Hirshfeld surfaces and break down fingerprint plots are a valuable and rapid tool for visualizing and analyzing the intermolecular interactions in Schiff bases complexes.

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