Template synthesis and spectral studies on mononuclear complexes of chromium(III) and manganese(II) with tetradentate N4 donor macrocycles.

The present article deals with the synthesis, spectral characterization and antimicrobial activity of a series of new complexes of chromium(III) and manganese(II)of general formula [Cr(Macn)Cl2]·Cl and [Mn(Macn)Cl2] respectively. These complexes were prepared via template reaction by mixing methanolic solution of diacetyldihydrazone, diacids (oxalic acid, succinic acid, glutaric acid and adipic acid) with CrCl3·6H2O and MnCl2·4H2O in 2:2:1 M ratios respectively. The newly synthesized complexes were characterized on the basis of chemical analysis and spectral studies like IR, UV, ESR and X-ray diffraction. An octahedral structure has been proposed for the chromium(III) and manganese(II)macrocyclic complexes. The synthesized complexes were further tested in vitro against fungi and bacteria in order to assess their antibacterial and antifungal activities. The studies demonstrate that the complexes possess antimicrobial properties.

Template synthesis, spectroscopic studies, antimicrobial, nematicidal and pesticidal activities of chromium(III) macrocyclic complexes.

A new series of Cr(III) macrocyclic complexes have been synthesized by template condensation of ligands 2-[4-chloro-2-(2-oxo-1,2-diphenyl-ethylideneamino)-phenylimino]-1,2-diphenyl-ethanone (ML(1)) and 2-[4-fluro-2-(2-oxo-1,2-diphenyl-ethylideneamino)-phenylimino]-1,2-diphenyl-ethanone (ML(2)) respectively, with appropriate diamines i.e. 1,2-phenylenediamine, 4- chloro 1,2-phenylenediamine and 4-fluro- 1,2-phenylenediamine in the presence of CrCl(3).6H(2)O. The ligands and their complexes have been characterized on the basis of elemental analyses, molecular weight determinations, conductance and magnetic susceptibility measurements and spectral studies including IR, ESR, electronic spectra and X-ray powder diffraction studies. On the basis of these studies, a six-coordinated octahedral geometry has been proposed for all these complexes. The newly synthesized ligands and their complexes have been screened for their antimicrobial, nematicidal and pesticidal activities. The results are indeed positive.

Synthesis, spectroscopic studies and electrochemistry of palladium (II) macrocyclic complexes derived from a new tetraazahalogen substituted ligands by template method and their antimicrobial and pesticidal activities.

A new series of Pd(II) macrocyclic complexes have been synthesized by template condensation of bis(benzil)4-chloro 1,2-phenylenediamine (ML1) and bis(benzil)4-fluro 1,2-phenylenediamine (ML2) respectively, with appropriate diamine i.e. 1,2-phenylenediamine, 4-chloro 1,2-phenylenediamine and 4-fluro 1,2-phenylenediamine in the presence of PdCl2 to form complexes of the type [Pd(C40H26N4ClF)]Cl2, [Pd(C40H27N4X)]Cl2 and [Pd(C40H26N4X2)]Cl2, where X=Cl, F. The complexes have been characterized with the help of elemental analysis, IR, 1H NMR, electronic spectra, conductance measurement, magnetic susceptibility, cyclic voltammetry and X-ray powder diffraction studies. On the basis of these studies a square planar geometry has been proposed around the metal ion. The newly synthesized ligands and their complexes have been screened for antimicrobial and pesticidal activities. The results obtained from bioassays indicate that this class of compounds can be utilized for the design of new substance with pesticidal activity and promising antimicrobial activity.