Abstract:A new macrocyclic coordination compound,tetra-(P-methoxyphenyl)porphyrinoxovanadium(Ⅳ)[T(P-OCH3)PPVO] was synthesized in propionic acid solvent. The composition of T(P-OCH3)PPVO was determined as C48H36N4O4VO? 4H2O by elemental analysis and EDTA complexometric methods. The UV-visible spectra showed that the formation of the title coordination compound,and the ligand and coordination compound are macrocyclic. Disappearance of the N-H stretching vibration peak in IR spectra of the T(P-OCH3)PPVO revealed the introduction of the central ion VO2+ into the porphyrin ring. The TG-DTA-DTG results demonstrated that the different dewatering mechanism of the ligand and complex are four molecules of H2O broken away in one step (the ligand),and two by two stepwise of the four H2O molecules(the complex). Sixteen distinct lines attributed to interaction of nuclear spin of vanadium(Ⅳ)with the 3dI electron appeared clearly in the ESR spectra of title macrocyclic compound,indicating that its structural model is a distorted octahedron belonging to C4v point group.