title: Synthesis and spectral investigations of mononuclear [N(6)], [N(8)] and dinuclear [N(10)] complexes of polyamide macrocycles: (57)Fe Mössbauer parameters of Fe(III) complexes.
abstract: New stable Fe(III) complexes of tetraamide [N(6)], [N(8)] and [N(10)] macrocyclic ligands are reported. One of them, [N(10)] is dinucleating, with two Fe(III) nuclei in the macrocyclic cavities. The structural features have been discussed on the basis of analytical, ESI mass, FT-IR, electronic, (1)H and (13)C NMR spectral studies. Magnetic moment studies indicate presence of anti-ferromagnetically coupled (Fe(3+)-Fe(3+)=S(5/2)-S(5/2)) spin-spin interactions in the dinuclear [N(10)] complex. (57)Fe Mössbauer measurements confirm Fe(+/-3/2-->+/-1/2) nuclear transitions supporting high-spin configuration of Fe(III) nuclei 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 A
authors.initials: ZA
authors.lastname: Siddiqi
authors.forename: Sarvendra
authors.initials: S
authors.lastname: Kumar
authors.forename: Mohd
authors.initials: M
authors.lastname: Khalid
authors.forename: M
authors.initials: M
authors.lastname: Shahid
mesh_terms: D055598:Chemical Phenomena; D005290:Ferric Compounds / Q000737:chemistry*; D047028:Macrocyclic Compounds / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D008280:Magnetics; D008958:Models, Molecular; D009757:Nylons / Q000138:chemical synthesis* / Q000737:chemistry*; D021241:Spectrometry, Mass, Electrospray Ionization; D013055:Spectrophotometry, Infrared; D017550:Spectroscopy, Fourier Transform Infrared; D015204:Spectroscopy, Mossbauer
chemical_list: D005290:Ferric Compounds; D047028:Macrocyclic Compounds; D009757:Nylons