Syntheses and characterization of coordination compounds of N-(2-mercaptoethyl)-4-(3' -carboxy-2' -hydroxyphenyl)·2·azetidinone

Abstract

A dioxane solution of N-(2-mercaptoethyl)-3-carboxy-2-hydroxybenzylideneimine, LH 3 (I) on reacting with chloroacetyl chloride in the presence of triethylamine, undergoes cyclization to form N-(2-mercaptoethyl)-4-(3'-carboxy-2'-hydroxyphenyl)-2-azetidinone, L'H 3 (II). A MeOH solution of L'H 3 reacts with Mn, Co II , Ni II , Cu II , II , II , Zr IV , MoO 2 2+ and UO 2 2+ ions to form the complexes [M(L'H).MeOH] 2 (where M = Mn, Co II or Ni II ), [Cu(L'H)] 2 , [M'(L'H)] (where M' = II , Cd, MoO 2 2+ or UO 2 2+ ) and [Zr(OH) 2 (L'H)] 2 . The compounds have been characterized on the basis of elemental analyses, molar conductance, molecular weight, spectral (IR, UV-Visible) studies and magnetic susceptibility measurements. L'H 3 behaves as a dibasic tridentate OON donor ligand in [Cu(L'H)] 2 , while it acts as a dibasic tetradentate OONS donor ligand in rest of the compounds. The complexes [M(L'H).MeOH] 2 (where M = Mn, Co II or Ni II ), [Cu(L'H)] 2 and [Zr(OH) 2 (L'H)] 2 are dimers, and the complexes [M'(L'H)] (where M' = Zn, Cd, MoO 2 2+ or UO 2 2+ ) are monomers. The dimeric complex [Cu(L'H)] 2 exhibits subnormal magnetic moment and is involved in antiferromagnetic exchange, while all other complexes are magnetically dilute. The octahedral structure for Mn II , Co, Ni II. MoO 2 2+ and UO 2 2+ complexes, square planar structure for Cu II complex, tetrahedral structure for Zn and Cd complexes, and pentagonal bipyramidal structure for Zr IV complex have been suggested.