Synthesis and study on aroylhydrazones having cyanovinylpyrrole

oleh: Poonam Rawat, R.N. Singh

Format: Article
Diterbitkan: Elsevier 2019-12-01

Deskripsi

A series of C-cyanovinylpyrrole containing aroylhydrazones (3a–c), derived from ethyl 2-cyano-3-(5-formyl-1H-pyrrol-2-yl)-acrylate and acid hydrazides: salicylhydrazide, isoniazid and 3,5-dinitrobenzohydrazide have been characterized by various spectroscopic techniques (1H NMR, 13C NMR, Mass, UV–Visible, Emission, FT-IR) and quantum chemical calculations. TD-DFT has been used to calculate the various electronic excitations and their nature. The emission spectra show that (3a–c) are good photoluminescent material due to intense emission at higher wavelength in yellow, green and blue region with high Stoke’s shift in the region 80–328 nm. The molar refractivity (MR) for (3a–c) is calculated as 109.28, 102.96, 119.14 esu, respectively. Natural bond orbital (NBO) analysis has been carried out to explore the various conjugative and hyperconjugative interactions within molecule and their second order stabilization energy (E(2)). Global electrophilicity index (ω = 5.41–8.11 eV) shows that (3a–c) molecules work as strong electrophiles. The local reactivity descriptors analyses such as Fukui functions (fk+, fk−), local softnesses (sk+, sk−) and electrophilicity indices (ωk+, ωk−) have been performed to determine the reactive sites within molecules. The first hyperpolarizabilities (β0) of (3a–c) have been computed and found to increase with electron withdrawing substituents. Keywords: Emission, TD-DFT, NBO, First hyperpolarizabilities