Abstract: Four coordination compounds,[Zn(Maape)2(H2O)2(NO3)2] (1, mononuclear), [Cu(Maape)2(H2O)2(NO3)2] (2, mononuclear), [Zn(Maape)2Cl2] (3, mononuclear), [Zn(Maape)(H2O)4SO4] (4, mononuclear) were synthesized with transition metal salts and the ligand (2-Methyl-acrylic acid 4-(pyridin-4-ylazo)-phenyl ester, Maape).The structures of all these compounds were determined by single crystal X-ray diffraction and structural analysis reveals that compounds 1-4 are mononuclear complexes.They were characterized by FT-IR and elemental analysis.The structural construction of these compounds is affected not only by the metal centers but also by the different counteranions.The structure of compounds 1 and 2 is similar which is mononuclear composed of a metal center, two anions and two ligands.Compound 3 is a mononuclear compound which contain a metal ion Zn(II), two chloride coanions and two Maape ligands in the asymmetric units in 3.And the asymmetric unit of compound 4 consists of a discrete mononuclear [Zn(Maape)(H2O)4SO4] molecule with the zinc atom locating at the two-fold symmetric axle.The ligand and its four complexes have the same UV absorption peak at 323 nm.

Key words: Four coordination compounds,[Zn(Maape)2(H2O)2(NO3)2] (1, mononuclear), [Cu(Maape)2(H2O)2(NO3)2] (2, mononuclear), [Zn(Maape)2Cl2] (3, mononuclear), [Zn(Maape)(H2O)4SO4] (4, mononuclear) were synthesized with transition metal salts and the ligand (2-Methyl-acrylic acid 4-(pyridin-4-ylazo)-phenyl ester, Maape).The structures of all these compounds were determined by single crystal X-ray diffraction and structural analysis reveals that compounds 1-4 are mononuclear complexes.They were characterized by FT-IR and elemental analysis.The structural construction of these compounds is affected not only by the metal centers but also by the different counteranions.The structure of compounds 1 and 2 is similar which is mononuclear composed of a metal center, two anions and two ligands.Compound 3 is a mononuclear compound which contain a metal ion Zn(II), two chloride coanions and two Maape ligands in the asymmetric units in 3.And the asymmetric unit of compound 4 consists of a discrete mononuclear [Zn(Maape)(H2O)4SO4] molecule with the zinc atom locating at the two-fold symmetric axle.The ligand and its four complexes have the same UV absorption peak at 323 nm.