Synthesis, spectral and microbial studies of 4-salicyldimino-3-phenyl/methyl-5- mercapto-1,2,4-triazole and their complexes with CoII, NiII, CuII, ZnII and CdII

Department of Chemistry, National Institute of Technology, Patna-800 005, Bihar, India

E-mail : madhub252@gmail.com

Department of Chemistry, Science College, Patna-800 005, Bihar, India

Manuscript received 23 August 2012, revised 12 February 2013, accepted 13 February 2013

The stable complexes of Co^II, Ni^II, Cu^II, Zn^II and Cd^II with (O, N, S) donor triazole derivatives, viz. 4- salicyldimino-3-methyl-5-mercapto-1,2,4-triazole (H₂ salmtr) and 4-salicyldimino-3-phenyl-5-mercapto-1,2,4-triazole (H₂ salptr) of composition [M(HL)₂ ] (M = Co^II, Ni^II, Cu^II, Zn^II or Cd^II and H₂L = H₂ salmtr and H₂ salptr) as well as [MLB] (M = Ni^II, Cu^II, Zn^II or Cd^II and B = H₂O or Py) have been prepared, analysed and their probable structure have been suggested from the studies of magnetic susceptibility, electrical conductance, IR data and electronic absorption spectral measurements. The bischelate [M(HL)₂ ] (M = Co^II, Ni^ll or Cu^II and H₂L = H₂ salmtr and H₂ salptr) shows UV spectral and magnetic moment values consistent with distorted octahedral geometry. The Zn^ll and Cd^II bischelates and monoligated complexes [MLB] (M = Zn^II, Cd^II and H₂L = H₂ salmtr or H₂ salptr) are four coordinated tetrahedral while [NiLB] and [CuLB] (B = H₂O or Py and H₂L = H₂ salmtr or H₂ salptr) are planar. The Cu^II, Zn^II and Cd^II complexes and ligands were screened for some antibacterial activity. The antimicrobial properties followed the order : H₂ salmtr < H₂ salptr < Zn^II < Cd^II < Cu^II (bischelates). The antifungal activity of [CdLPy] and [CuLPy] was greater than ZnLPy.