title: Mössbauer and electronic spectral characterization of homo-bimetallic Fe(III) complexes of unsymmetrical [N10] and [N12] macrocyclic ligands.
abstract: The homo-bimetallic complexes of stoichiometry Fe2(L)ClO4(ClO4)2 where L are novel unsymmetrical [N10] (L1.2HClO4) and [N12] (L2.2HClO4) macrocyclic ligands, have been prepared. The ligands were obtained from an in situ capping reaction of the reactive substrate, N,N'-bis(N-ethylaniline)hydrazine-1,2-diimine with a mixture of aniline or 1,3-diaminopropane and HCHO in presence of HClO4. The compounds have been characterized by elemental analyses, conductometric, IR, FAB-mass and electronic spectral studies. IR data of complexes suggest coordination from unsymmetrical aza sites as a tridentate (N,N,N) or tetradentate (N,N,N,N) ligand. mu(eff) values of the complexes suggest presence of antiferromagnetically coupled (Fe3+-Fe3+=S5/2-S5/2) spin exchange. Mössbauer parameters of the complexes support (+/-3/2)-->(+/-1/2) nuclear transition in high-spin configurations of Fe(III) nuclei of the homo-bimetallic complexes with the presence of Kramer's double degeneracy.
authors.affiliation: Department of Chemistry, Aligarh Muslim University, Aligarh 202002, India. zafarasiddiqi@yahoo.co.in
authors.forename: Zafar Ahmad
authors.initials: ZA
authors.lastname: Siddiqi
authors.forename: Razia
authors.initials: R
authors.lastname: Arif
authors.forename: Sarvendra
authors.initials: S
authors.lastname: Kumar
authors.forename: Mohd
authors.initials: M
authors.lastname: Khalid
mesh_terms: D055598:Chemical Phenomena; D002627:Chemistry, Physical; D004583:Electrons; D005290:Ferric Compounds / Q000737:chemistry*; D008024:Ligands; D047028:Macrocyclic Compounds / Q000737:chemistry*; D008280:Magnetics; D015394:Molecular Structure; D013057:Spectrum Analysis; D013237:Stereoisomerism
chemical_list: D005290:Ferric Compounds; D008024:Ligands; D047028:Macrocyclic Compounds