Structural and Vibrational Analysis of (E)-N’-(Pyridin-2-yl)Methylene)Nicotinohydrazide Using Quantum Chemical Calculation

Abstract

ABSTRACT. FT-IR, FT-Raman and UV-Vis spectra of the Schiff base compound (E)-N'-(Pyridin-2-yl) methylene) nicotinohydrazide (P2CNH) have been recorded and analyzed. The optimized molecular structures, vibrational assignment of P2CNH have been investigated by using DFT/B3LYP/6-311++G(d,p) level of theory. The Non-linear optical behavior of the title compound was measured using first order hyperpolarizability calculation. Hyperconjugative interaction and electron densities of donor (i) and acceptor (j) bonds were calculated using NBO analysis. The energy gap of the molecule was found using HOMO and LUMO calculation. The electronic transition was studied using TD-DFT method. In addition of mulliken atomic charges and MEP surface have been also analyzed.

Synthesis and Vibrational Spectral Analysis of (E)-Nʹ- (Pyridin-2-Ylmethylene) Isonicotinohydrazide - A Combined Experimental and Theoretical Study

“…This assignment is in agreement with literature [40]. These assignments are positively ( ̴ 4, 30, 10cm-1) deviated from our earlier assignments (P2MNH) [23], which may be due to the positive magnitude (0.11) of N14 atom creates the possibility of transformation of electron density (ED) from H-15 to N-14. This ED distribution make the N-H bond stronger and hence there is positive deviation.…”

“…The bond length of C 16 -C 21 is positively (0.039Å) deviated from the bond length of C 5 -C 11 (1.468Å), which is due to the carbon atom (C 16 ) of carbonyl group positioned in between nitrogen (N 14 ) and C 18 on pyridine ring 2. In hydrozone moiety, the nitrogen atom (N 14 ) belongs to N-H group exert a large attraction of the valence electron cloud of the H 15 atom resulting an increase in the N-H force constant and hence the corresponding (N-H) bond length is decreased (1.016Å) [23] our previous study P2MNH. The 11 -C 5 -C 4 and C 11 -C 5 -N 6 are 122.25˚ and 114.84˚, respectively, whereas the expected bond angle value would be 120˚.…”

“…Recently, Ramesh Babu et al, (2014) [41] assigned the νN-H, and βN-H modes respectively to the bands observed at 3349 and 1516 in FTIR spectrum. In our previous study, the medium/weak bands observed at 3373/1476cm-1 in FTIR/FT-Raman spectra were assigned to νN-H and βN-H modes, respectively [23].…”

“…The positive ( ̴ 2˚) deviation in bond angle (C 11 -C 5 -O 4 ) is due to the repulsion between C 11 and C 5 atoms are having negatively charged electron densities. Similarly the negative ( ̴ 6˚ ) deviation in bond angle C 11 -C 5 -N 6 is probably due to the attraction between electron rich carbon (C 11 ) and the electron deficient nitrogen (N 6 ) centres [23]. In pyridine ring 2, the calculated bond angles of C 16 …”

“…The band gap, HOMO & LUMO energies, MEP map and Mulliken atomic charges were also calculated and analyzed [22]. In our previous study, the FT-IR, FT-Raman and UV-Vis spectra of the Schiff base compound (E)-N'-(Pyridin-2-yl) methylene) nicotinohydrazide (P2MNH) had been recorded and analyzed [23]. The optimized molecular structure, vibrational assignments and NMR chemical shift for P2MNH have been investigated using DFT/B3LYP/6-311++G(d,p) level of theory.…”