Computational design and molecular modeling of the interaction of nicotinic acid hydrazide nickel-based complexes with H 2 S gas.

The application of nickel complexes of nicotinic acid hydrazide ligand as a potential gas-sensor and adsorbent material for H 2 S gas was examined using appropriate density functional theory (DFT) calculations with the ωB97XD/Gen/6-311++G(d,p)/LanL2DZ method. The FT-IR spectrum of the synthesized ligand exhibited a medium band at 3178 cm -1 attributed to ν (NH) stretching vibrations and strong bands at 1657 and 1600 cm -1 corresponding to the presence of ν (C[double bond, length as m-dash]O) and ν (C[double bond, length as m-dash]N) vibration modes. In the spectrum of the nickel(ii) complex, the ν (C[double bond, length as m-dash]O) and ν (C[double bond, length as m-dash]N) vibration bands experience negative shifts to 1605 cm -1 and 1580 cm -1 , respectively, compared to the ligand. This indicates the coordination of the carbonyl oxygen and the azomethine nitrogen atoms to the Ni 2+ ion. Thus, the sensing mechanism of the complexes indicated a short recovery time and that the work function value increases for all complexes, necessitating an excellent H 2 S gas sensor material. Thus, a profound assertion was given that the complex sensor surfaces exhibited very dense stability with regards to their relevant binding energies corresponding to various existing studies.