Table 2: Assignments of the important experimental and calculated vibrational modes and 1H NMR data of HL ligand.

Experimental IR (cm−1) Calculated frequencies Intensity Assignment 1H NMR data (ppm)

3,431 (s,b)νOH (water of crystallization)10.31 s (OH), 9.54 s (HC=N),
2,920 (m)2,50785νOH9.06–8.03 m (quinoline ring),
1,68125νR, δOH, νC=N7.81–6.86 (phenyl ring)
1,6618νC=Nquinoline, νR
1,65121νR, νC=Nazomethine
1,623 (s)1,62810νR, νC=Nquinoline, νC=Nazomethine
1,542 (m)1,559, 1,55310, 6νR, δOH
1,437 (m)1,470, 1,44610, 7δCH, νC−O, νsym(NO2)
1,238 (m)1,27650δCH, νC−O, νsym(NO2)
826 (mw)82011νR, δscissor(NO2)

ν, stretch; δ, in-plane bend; m, medium; s, strong; b, broad; mw, medium weak.