Synthesis, Characterization, and Bioactivity of Schiff Bases and Their Cd^𝟐+, Zn^𝟐+, Cu^𝟐+, and Ni^𝟐+ Complexes Derived from Chloroacetophenone Isomers with S-Benzyldithiocarbazate and the X-Ray Crystal Structure of S-Benzyl-β-N-(4-chlorophenyl)methylenedithiocarbazate

Table 3

IR spectral data of SBDTC, free ligand, and their complexes.

Compound	Infrared absorption bands (frequency, cm^−1)
	𝜈(NH)	𝜈(NH2)	𝜈(C=S)	𝜈(N–N)	𝜈(C=N)	𝜈(M–N)*	𝜈(O–H)	𝜈(Other bands)
SBDTC	3451	3250, 3172	950	1048	—	—	—	2 peaks at 710, 698
NS4	3436	—	950	1051	1638	—	—	(i) Aromatic C–H at 3166; (ii) Peak at 827; (iii) Peak at 704
NS2	3447	—	972	1023	1590	—	—	(i) Aromatic C–H at 3285; (ii) Peak at 704; (iii) Peak at 622
Zn(NS4)2	—	—	—	1000	1400	Obscured by other peaks	3432	Broad peak ~(500–900)
Cd(NS4)2	—	—	—	1086	1450	600	3430	(i) Peak at 822; (ii) Peak at 700
Zn(NS2)2	—	—	—	1121	1578	750	3436	(i) Peak at 697; (ii) Peak at 619
Cd(NS2)2	—	—	—	1120	1421	Obscured by other peaks	3448	(i) Peak at 700; (ii) Peak at 619
Ni(NS4)2	—	—	—	1116	1400	500	3400	(i) Peak at 827; (ii) Peak at 703
Cu(NS4)2	—	—	—	1117	1406	619	3420	(i) Peak at 825; (ii) Peak at 695
Cu(NS2)2	—	—	—	1120	1406	Obscured by other peaks	3410	Peak at 619
Ni(NS2)2	—	—	—	1110	1421	510	3430	Peak at 620

(M–N)*: this refers to the dative bond that is formed between the metal ion (M) and the nitrogen (N) atom.