Coordination chemistry and bioactivity of Ni2+, Cu2+, Cd2+ and Zn2+ complexes containing bidentate Schiff bases derived from S-benzyldithiocarbazate and the X-ray crystal structure of bis[S-benzyl-β-N-(5-methyl-2-furylmethylene)dithiocarbazato]cadmium(II)

Abstract

New bidentate isomeric NS and NS′ Schiff bases were derived from the condensation of Sbenzyldithiocarbazate (SBDTC) with 5-methyl-2-furyldehyde and 2-furyl-methylketone. Reaction of NS ligand with Ni(II), Cu(II), Cd(II) and Zn(II) salts gave solid complexes. Only the Ni(II) complex of the NS′ ligand was isolated. All complexes were characterized by a variety of physico-chemical techniques, viz. elemental analyses, molar conductivity, i.r. and electronic spectral studies. The Schiff bases behaved as uninegatively charged bidentate ligands. Square-planar structures have been proposed for the Cu(II) complex containing the NS Schiff base ligand and the Ni(II) complexes of the bidentate NS and NS′ Schiff base ligands. Single crystal X-ray diffraction study of [Cd(NS)2] showed that the complex was bis chelated with a distorted tetrahedral structure. The antimicrobial properties of the Schiff bases and their metal complexes indicate that the organic compounds are stronger antifungal agents than their complexes with the metals studied. However, the zinc complex of the Schiff base, S-benzyl-β-N-(5-methyl-2-furyl)methylenedithiocarbazate, (NS), was found to be highly active against CEM-SS (Human cell T-lymphoblastic leukemia) with a CD50 value of 2.0 μg cm−3, while [Cd(NS)2] was moderately active with a CD50 value of 4.95 μg cm−3. None of the compounds were found to be active against HT-29 (Human colon adenocarcinoma cells). The bioactivity of a previously reported tridentate NNS Schiff base (SBD1) and its metal complexes with nickel(II) and copper(II) are also discussed.

Syntheses and crystal structures of two Schiff-base copper(II) complexes with urease inhibition

“…Identifying the biological role of copper, primarily through techniques associated with the interface of biology, biochemistry, and coordination chemistry [1][2][3], shows that it is primarily in redox reactions and as a biological catalyst, although much remains to be understood [4,5]. An extensive effort has been made to prepare and characterize a variety of copper(II) complexes in an attempt to model the physical and chemical behavior of copper-containing enzymes [6].…”

Experimental and density functional studies on two structurally similar antipyrine derivatives: 4-(2-hydroxy-5-nitrobenzylidene-amino)-1,2-dihydro-1,5-dimethyl-2-phenylpyrazol-3-one and 4-(3-bromo-5-chloro-2-hydroxybenzylideneamino)-1,2-dihydro-1,5-dimethyl-2-phenylpyrazol-3-one

“…Estimates of half-life and systemic clearance of antipyrine have been used for the in vivo assessment of hepatic drug oxidation in different species [14]. Schiff base derivatives have demonstrated significant biological activities and new examples have been tested for their antitumor, antimicrobial, and antiviral activities [15][16][17].…”

Catechol Oxidase, Phosphatase-Like Activity, DNA/BSA Binding Studies of RuII Complexes of S-Allyldithiocarbazate: Synthesis and Spectral Studies

“…The IR spectra do not show any υ(SH) band at 2700 cm -1 , but the presence of broad υ(NH) band in the region 3107-3120 cm -1 suggests that the free ligands are in keto form in solid state. 33 The strong bands observed at 1610, 1660 cm -1 and 848, 828 cm -1 confirm the formation of ligands with υ(C=N), υ(C=S), but IR spectra of complexes show reduction in the frequency of azomethine group and the new band appeared at 1596 and 1647 cm -1 indicating the coordination of azomethine group to ruthenium. 34 Absence of band due to υ(C=S) in the complexes confirms the coordination of Schiff bases to ruthenium and the disappearance is due to negative coordination of ligand in the form of υ(C−S) and the new band appeared in the complexes 1 and 2 at 829, 800 cm -1 concludes tautomerism of (−NH−C=S) group and coordination of thiolatesulfur after deprotanation.…”