Synthesis, investigation and spectroscopic characterization of piroxicam ternary complexes of Fe(II), Fe(III), Co(II), Ni(II), Cu(II) and Zn(II) with glycine and DL-phenylalanine.
The ternary piroxicam (Pir; 4-hydroxy-2-methyl-N-(2-pyridyl)-2H-1,2-benzothiazine-3-carboxamide 1,1-dioxide) complexes of Fe(II), Fe(III), Co(II), Ni(II), Cu(II) and Zn(II) with various amino acids (AA) such as glycine (Gly) or DL-phenylalanine (PhA) were prepared and characterized by elemental analyses, molar conductance, IR, UV-Vis, magnetic moment, diffuse reflectance and X-ray powder diffraction. The UV-Vis spectra of Pir and the effect of metal chelation on the different interligand transitions are discussed in detailed manner. IR and UV-Vis spectra confirm that Pir behaves as a neutral bidentate ligand coordinated to the metal ions via the pyridine-N and carbonyl group of the amide moiety. Gly molecule acted as a uninegatively monodentate ligand and coordinate to the metal ions through its carboxylic group, in addition PhA acted as a uninegatively bidentate ligand and coordinate to the metal ions through its carboxylic and amino groups. All the chelates have octahedral geometrical structures while Cu(II)- and Zn(II)-ternary chelates with PhA have square planar geometrical structures. The molar conductance data reveal that most of these chelates are non electrolytes, while Fe(III)-Pir-Gly, Co(II)-, Ni(II)-, Cu(II)- and Zn(II)-Pir-PhA chelates were 1:1 electrolytes. X-ray powder diffraction is used as a new tool to estimate the crystallinity of chelates as well as to elucidate their geometrical structures.
Chemistry Department, Faculty of Science, Cairo University, Giza, Egypt. ggenidy@hotmail.com
Gehad G
GG
Mohamed
Nadia E A
NE
El-Gamel
D002614:Chelating Agents / Q000494:pharmacology; D005998:Glycine / Q000737:chemistry*; D008024:Ligands; D008280:Magnetics; D019216:Metals, Heavy / Q000737:chemistry*; D015394:Molecular Structure; D010649:Phenylalanine / Q000737:chemistry*; D010894:Piroxicam / Q000031:analogs & derivatives / Q000138:chemical synthesis / Q000737:chemistry*; D013053:Spectrophotometry; D014961:X-Ray Diffraction
D002614:Chelating Agents; D008024:Ligands; D019216:Metals, Heavy; D010894:Piroxicam; D010649:Phenylalanine; D005998:Glycine