N-2-[4,6-DIMETHYLPYRIDYL]-N′-PHENYLTHIOUREA (HDMPyPt) TRANSITION METAL COMPLEXES
摘要:
Several types of new metal complexes of N-2-[4,6-dimethylpyridyl]-N'-phenylthiourea (HDMPyPT) have been prepared from M(OAC)(2) [M = Cu(II), Zn(II), Ni(II), Co(II), UO2(VI)], HAuCl4, Na-2[PdCl4] and metal chlorides [M=Co(II), Sm(III), Nd(III)]. HDMPyPT behaves in a monodentate fashion via the pyridyl nitrogen in all of the complexes except the Cu(II), Pd(II), and Au(III) complexes. The participation of the thioketo and/or thioenol groups, in addition to the pyridyl nitrogen, has been confirmed in the latter three complexes. The role of the methyl groups in positions 4 and 6 as well as the pH of the reaction mixture has been investigated. Also, the effect of anions (Cl- and OAc-) attached to the metal salts on the structure of the complexes has been studied. The stereochemistry of the metal complexes has been determined from spectral (IR, UV-Vis., H-1 NMR and mass) and magnetic measurements. The results suggest a square-planar geometry for the Pd(II) and Au(III) complexes, a tetrahedral structure for one of the Co(II) complexes and octahedral geometry for the other metal complexes. The amount of solvents inside or outside the coordination sphere has been determined using TGA and DTA measurements.