Prateeti Chakraborty

Study of non-covalent interactions is the main piller of supramolecular chemistry. Mostly it plays an important role in controlling the physical property as well as structural topology. In order to explore that role a series of four mononuclear Schiff-base complexes, namely, [Zn(L)(NCS)₂] (1), [Zn(L)(N₃)₂] (2), [Cu(L)(NCS)₂] (3) and [Ni L)(2bpy)(NCS)](ClO₄) (4), [where L = N,N-dimethyl-N′-

(phenyl-pyridin-2-yl-methylene)-ethane-1,2-diamine and 2bpy = 2-benzoylpyridine] were synthesized and the role of different non-covalent weak interactions responsible for the crystal packing of the complexes were thoroughly investigated. All of them were structurally characterised by X-ray diffraction analysis. In addition to conventional CH₃ …….. π and π…..π interactions, the importance of unconventional C–H ……π interactions in the crystal packing of compounds 1–4 was investigated by means of Hirshfeld surface analysis and DFT calculations. In these unconventional C–H…….π interactions, the π-system (electron donor) is provided by the pseudohalide coligands. The interactions formed by the π-system depend on the nature of the pseudohalide (N₃, NCO, NCS or NCSe) as demonstrated by molecular electrostatic potential calculations. Additionally, we have explored the photophysical properties of these complexes. Finally, we have combined a search in the Cambridge Structural Database and DFT energy calculations to analyse the rare ambidentate behaviour of SCN within the same complex.

Audience take-away:

• By explaining different weak interactions present in the complexes audience will be able to learn the behavior of different pseudohalide moiety in formation of the complexes.
• The audience will learn the synthetic methodology of above mentioned coordination complexes.
• This research will help to understand the interactive behavior of pseudo halide chemistry.
• The simple synthetic strategy will help researchers to develop such coordination complexes in no time.