“… 31 1 H NMR of S1 (400 MHz, CDCl 3 ) δ: 0.85 (3H, terminal C H 3 ), 1.3 (8H, aliphatic methylene units 4C H 2 ), 3.8 (2H, aliphatic methylene unit attached to nitrogen atom =N–C H 2 ), 7–9 (7H, attached to the aromatic rings and 1H for C H =N), and 11.2 (1H for the O H group). 32 , 33 13 C NMR: δ ppm = 14.2 (terminal aliphatic CH 3 ), 22–32 (aliphatic CH 2 ), 62.1 (aliphatic N–CH 2 ), 118.5 (C≡N), 122–132 (aromatic CH), 157.1 (C–N), 157.6 (CH=N), 164.1 (C–OH).…”