Synthetic, spectroscopic, SC-XRD and nonlinear optical analysis of potent hydrazide derivatives: A comparative experimental and DFT/TD-DFT exploration

Abstract

In this work, we reported the synthesis of hydrazide derivatives namely; N’-(4-(prop-2-ynyloxy)benzylidene)isonicotinohydrazide (1) and 4-methyl-N’-(4(prop-2-ynyloxy)benzylidene)- benzenesulfonohydrazide (2), their characterization through spectroscopic techniques as EIMS, 1H NMR, FT-IR, UV–Visible and single crystal X-ray diffraction (SC-XRD). Quantum chemical methods were performed for both compounds (1) and (2) to explore the structural, spectral and electronic properties for comparative analysis with experimental data. The theoretical vibrational spectra (FT-IR), frontier molecular orbitals (FMOs) and nonlinear optical (NLO) analysis were performed at DFT/B3LYP/6-311 + G(d,p) level. Natural bond orbitals (NBOs) analysis was carried out at M06-2X/6-311G(d,p)level of theory. However, the time dependent density functional theory (TDDFT) was used for the calculations of vertical electronic transition states at B3LYP level with 6-311 + G(d,p) basis set. The NBO analysis revealed that both compounds (1) and (2) have high molecular stability due to hyperconjugative interactions. Moreover, the global reactivity descriptors were calculated using the energies of FMOs. NLO analysis showed that both compounds (1) and (2) have significant NLO properties as compared to prototype compound (urea) which disclosed their potential for technology related applications. Overall, a well synchroneity is found between the experimental dataand DFT based results of both compounds.