Spectral investigation of the intramolecular charge-transfer in some aminotriazole Schiff bases

Structural Characterization, DFT Calculation, NCI, Scan-Rate Analysis and Antifungal Activity against Botrytis cinerea of (E)-2-{[(2-Aminopyridin-2-yl)imino]-methyl}-4,6-di-tert-butylphenol (Pyridine Schiff Base)

“…It is important to remark that, due to the ATR limitations [ 24 ], the bands assigned to the –OH appeared to be thinner than bands obtained with the KBr pellet. Other authors reported broader bands in the range of 3500–3000 cm −1 , due to stretching νOH group engaged in the IHB [ 23 , 25 ]. Nevertheless, we were unable to observe those bands in our FTIR, probably due to the overlapping with bands assigned to νNH.…”

“…Other remarkable bands were observed at 1607 cm −1 , and 1589 cm −1 , assigned as νHC=N (azomethine), and νC=C, respectively. It is worth to underline that the azomethine group is usually assigned to around 1640 cm −1 [ 23 , 25 ]. The lower values observed for νHC=N can be explained by the interaction of the azomethine and the hydroxyl groups, both involved in the IHB, as previously reported for similar Schiff bases [ 23 ].…”

New synthetic chitosan derivatives bearing benzenoid/heterocyclic moieties with enhanced antioxidant and antifungal activities

“…For 2ATCMCS, compared to CMCS, the new peaks appear at 6.69(a), 7.16 ppm(b) respectively, which can be attributed to protons of thiazole (Laczkowski et al, 2016). After the introduction of the aminotriazole, new characteristic peaks appear at 6.76-7.03 ppm, which can be assigned to protons of aminotriazole (Issa, Hassib, Abdelaal, & Kenawi, 2011). As to the 1 H NMR spectra of ANCMCS, CANCMCS, FANCMCS and CANCMCS, the peaks of benzene protons at 6.32-8.12 ppm appear, confirming the existence of benzene (Eren & Unal, 2013;Nellaiappan & Kumar, 2018;Zhang et al, 2018).…”

“…3, some rules could be concluded from the two antioxidant activities of the chitosan and chitosan derivatives as follows: firstly, the enhanced radical scavenging activity of chitosan derivatives bearing benzenoid / heterocyclic moieties are very significant. It is attribute to the introduction of the aniline or amino heterocyclic moieties, which can exert the effects on radical scavenging activity by destroying free radical chain reactions (Issa et al, 2011;Kritchenkov et al, 2020;Xu, Aotegen, & Zhong, 2017). Secondly, the order of antioxidant activities is ranked as follows:…”

Physicochemical and Theoretical Characterization of a New Small Non-Metal Schiff Base with a Differential Antimicrobial Effect against Gram-Positive Bacteria

“…Other absorptions were observed at 1666.50 cm −1 , 1616.35 cm −1 , and 1570.06 cm −1 , assigned as νC=O (carbonyl group), νHC=N (azomethine), and νC=C, respectively. Although the azomethine group is usually assigned to absorptions at around 1640 cm −1 [ 27 ], the SB-1 azomethine group (1616.35 cm −1 ) can be explained by the presence of the IHB, as described for other similar molecules [ 26 ]. SB-2, for its part, showed a characteristic pattern in line with previous studies [ 25 ] ( Figure S15 ).…”