title: Spectral and magnetic properties of phenylazo-6-aminouracil complexes.
abstract: Complexes of Co(II), Ni(II) and Cu(II) with substituted phenylazo-6-aminouracils containing (-H, p-OH, p-CH(3), p-OCH(3) p-COOH) have been synthesized and characterized by elemental analysis, magnetic measurements and spectral measurements (IR, UV-Vis, ESR). Infrared spectra assigned the fundamental bands of the major groups, O-H, N-H, C-H, C=O, C=N, N=N, C-N and C-O (nu, delta and gamma modes of vibrations). The absence of nu(OH) and the appearance of nu(C=O) in the infrared spectra of the free ligands of 5-(p-tolyl and p-anisylazo)-6-aminouracil, assigned the keto structure, whereas in cases of 5-(phenyl, p-hydroxyphenyl and p-carboxyphenylazo)-6-aminouracil ligands, the data showed strong nu(OH) and nu(C=O) bands to assign keto-enol tautomerisms. The modes of interactions between the ligands and the metals were discussed, where oxygen and nitrogen atoms (of amino-amide groups) are involved in chelation. The azo group was not involved in chelation for all the prepared complexes except those of copper complexes derived from 5-(phenyl, p-tolyl, p-hydroxyphenyl and p-carboxyphenylazo)-6-aminouracils. The room temperature effective magnetic moment values, the Nujol mull spectra and ESR proved that all the prepared complexes were of octahedral geometry, except the nickel complex derived from 5-(phenylazo)-6-aminouracil and cobalt complex derived from 5-(p-carboxy-phenylazo)-6-aminouracil were square planar.
authors.affiliation: Chemistry Department, Faculty of Science, Alexandria University, Alexandria, Egypt. drmsmasoud@yahoo.com
authors.forename: Mamdouh S
authors.initials: MS
authors.lastname: Masoud
authors.forename: Saeda A
authors.initials: SA
authors.lastname: Abou El-Enein
authors.forename: Mohamed E
authors.initials: ME
authors.lastname: Ayad
authors.forename: Ahmed S
authors.initials: AS
authors.lastname: Goher
mesh_terms: D003300:Copper / Q000737:chemistry; D008280:Magnetics; D008670:Metals / Q000737:chemistry; D008956:Models, Chemical; D009532:Nickel / Q000737:chemistry; D013053:Spectrophotometry / Q000379:methods*; D013055:Spectrophotometry, Infrared; D013237:Stereoisomerism; D014498:Uracil / Q000737:chemistry*
chemical_list: D008670:Metals; D014498:Uracil; D003300:Copper; D009532:Nickel