Mn(II), Co(II), Ni(II) and Cu(II) complexes of a tertraaza macrocyclic ligand: Synthesis, characterization and biological screening

Abstract

Manganese(II), cobalt(II), nickel(II) and copper(II) complexes with 1,5,11,15-tetraaza-21,22-dioxo-tricyclo [19,3,1,I 6,10 ]-5,10,15-20-dicosatetraene (L), as a new macrocyclicligand, have been synthesized with and characterized by elemental analysis, molar conductance measurements, magnetic susceptibility measurements, mass, IR, electronic and EPR spectral studies. The molar conductance measurements of the complexes in DMF correspond to non-electrolytic nature of Mn(II), Co(II) and Cu(II) complexes, while showing a 1:2 electrolyte for thew Ni(II) complexe. Thus, these complexes may be formulated as [M(L)X 2 ] and [Ni(L)]X 2 (where M = Mn(II), Co(II) and Cu(II) and X = Cl -and NO 3 -). On the basis of IR, electronic and EPR spectral studies, an octahedral geometry has been assigned for Mn(II) and Co(II), a square planar for Ni(II) and tetragonal for Cu(II) complexes. In vitro ligand and its metal complexes were also screened against the growth of some fungal and bacterial species in order to assess their antimicrobial properties.

Synthesis, characterization and structural studies of binuclear nickel(II) complexes derived from dihydroxybenzaldehyde thiosemicarbazones, bridged by 1,2-bis(diphenylphosphino)ethane

“…On the other hand, the electronic absorption spectra of Ni(II) complexes are characterized by a broad band at the range of 353-359 and 405-414 nm which may be assigned to two allowed transitions 1 A 1 g (D) fi 1 Eg (G) and 1 A 1 g (D) fi 1 B 2 g (G) , respectively. Moreover, at room temperature these complexes show a diamagnetic behavior which indicates the square planar environment around the Ni(II) ion (Chandra et al, 2009;Lever, 1968;Prakash et al, 2011;Shayma, 2010c,d).…”

Synthesis, Characterization, and Biological Evaluation of Unimetallic and Heterobimetallic Complexes of Bivalent Copper

“…A medium intensity band observed in the far IR region of the metal complexes (460–470) cm −1 was assigned to (Cu–N). The far IR spectra show a distinct band at 317 cm −1 attributed to (Cu–Cl) band [ 24 ], which clearly indicates the presence of chlorine bonded with central metal (i.e., Cu) ion. Hence, the IR spectra support an octahedral geometry in case of heterobimetallic complexes further verified by the ESR spectra.…”

Synthesis, Spectral, Thermal and Biological Studies of Some Metal Complexes Derived from Heterocyclic Mono Azo Dye Ligand 2'[(2'-Hydroxy-4-methyl phenyl)azo]imidazole

“…The spectral data and the magnetic moment of prepared metal complexes are presented in Table- ) may be assigned n→π* charge transfer transition due to presence conjugation in the imidazole ring [33,40].The electronic spectrum of the Cr(III) complex displayed bands at 240 nm (41667 cm -1 ) and 480 nm (20833 cm -1 ). These two bands are assignable to center ligand and 4 A2g→ 4 T1g(F) transitions respectively in an octahedral environment [24,34].…”