A New Class of Tetraaza Macrocyclic Complexes of Divalent Tin: Synthesis, Characterization and Fungicidal Properties

Abstract

Tin(II) complexes of tetraaza macrocycles have been prepared by template process using malonic, succinic and adipic acids with 1,2-diaminoethane and 1,3-diaminopropane. The reaction proceed smoothly to completion. The complexes were characterized by elemental analyses, molecular weight determinations, infrared and 'H NMR spectral studies. The elemental analyses are consistent with the formulation of complexes as [Sn(MacroC n )Cl 2 ]. All the complexes are stable and monomeric as indicate by molecular weight determinations. The spectral studies confirm the proposed framework of the new macrocyclic complexes and indicate an octahedral environment around the central tin atom. The potential binding sites being the nitrogen atoms of the ligand. The biological activities of starting materials and their metal complexes have been studied by screening the compounds against Fusarium oxysporum and Aspergillus niger.

Biologically relevant tetraazamacrocyclic complexes of manganese: synthetic, spectral, antimicrobial, antifertility and antiinflammatory approach

“…Due to the complexity of biological system, it is rather difficult to stipulate the exact mechanism for such activities. However, the increased biocidal properties after complexation can be very well explained by chelation theory [11]. Chelation reduces the polarity of the metal ion, mainly by the partial sharing of its positive charge with the chelate rings.…”

“…As our programme for the development of tetraazamacrocyclic complexes, we have recently reported [11][12][13][14][15] tin complexes of various macrocycles. Such studies have established [16] that [dicyclohexylcarbodiimide] (DCHC) and [4-dimethylaminopyridine] (DMAP) can act as good condensing reagents for the condensation of primary amine and dicarboxylic acid.…”

DNA binding and antibacterial properties of ternary lanthanide complexes with salicylic acid and phenanthroline

“…Furthermore, the antibacterial activities of heavy rare earth complexes are stronger than those of the light rare earth complexes. The enhanced antibacterial activities of the complexes presumably result from the increase in liposolubility of the lanthanide complexes by the chelate effect …”

Microwave-Assisted Synthesis, and Stereochemical and Biological Aspects of Some Antimony(III) and Bismuth(III) Complexes with Biologically Potent Bidentate Schiff Bases

“…It is also evident that the complexes having sulfur as a donor atom in the ligand system display higher activity than those that do not have it. 39 6. Replacement of bismuth with antimony in its compounds reduced the compounds' antibacterial activities, 40,41 and we have also confirmed that antimony analogues of a compound have substantially lower levels of activity.…”