Complexing Behaviour and Antifungal Activity of N-[(1E)-1-(1H-Benzimidazol-2-yl)ethylidene]morpholine-4-carbothiohydrazide and Related Ligand with Metal Ions

Abstract

The coordination complexes of bivalent metal ions with N-[(1E)-1-(1H-Benzimidazol-2-yl)ethylidene]morpholine-4-carbothiohydrazide (H 2 bmctz, H 2 L-1) and N-[(1E)-1-(1H-Benzimidazol-2-yl)(phenyl)methylidene] morpholine-4-carbothiohydrazide (H 2 bpmctz, H 2 L-2) were prepared and their neutral, monoanionic, and dianionic forms of ligands of compositions [M(H 2 L)X 2 ] (M= Co II , Ni II , Cu II , Zn II , Cd II , or Pd II , X=Cl − or Br − , and H 2 L=H 2 L-1 or H 2 L-2), [M(HL) 2 ] n H 2 O where (M= Co II , Cu II , Mn II , Ni II , Zn II or Cd II , H 2 L=H 2 L-1 or H 2 L-2, and n = 0 or 2), and [MLB] n B (M= Cu II , Ni II , Zn II , Cd II , or Pd II , B=H 2 O, Py, or Y -pic, n = 0 and n = 1 if B=H 2 O for Ni(II) and H 2 L=H 2 L-1 or H 2 L-2) have been characterised by magnetic susceptibility measurements, electrical conductance values, and spectral properties. The magnetic moment value of [M(HL 2 )] (M= Mn II , Ni II , Fe II or Cu II ) type complexes is consistent with high spin octahedral structure while those of [M(H 2 L)X 2 ] (M= Co II , Ni II , Cu II , Zn II , or Cd II , X=Cl − or Br − ) possess five coordinated trigonal bipyramidal geometry. The adduct complexes [MLB]· n B (M= Ni II , or Cu II , B=H 2 O, Py, or Y -pic) are four coordinated planar and those of Zn II and Cd II complexes [MLB], (H 2 L=H 2 L-1 or H 2 L-2, B=H 2 O, Py or Y -pic) are tetrahedral. These ligands have been suggested to coordinate as tridentate (N N S) donor molecule in complexes of type [M(H 2 L)X 2 ], [M(HL) 2 ], and [MLB]. The antifungal activity of ligands and some of their metal complexes were studied and it was observed that metal complexes show higher activity than free ligand.