Structures of Ni(II), Pd(II) and Cu(II) complexes with 1,2-bis(5,5,5-trifluoro-4-oxopent-2-en-2-amino)benzene

A new fluorine-containing tetradentate ligand 1,2-bis(5,5,5-trifluoro-4-oxopent-2-en-2-amino)benzene and its complexes with Ni(II), Pd(II) and Cu(II) are characterized by single crystal X-ray diffraction. It is found that the enaminoketone fragments of the ligand are identical in bond lengths and angles; they are almost planar, and make the angles of 51.3A degrees to the plane of the benzene ring. The structures of Ni(II), Pd(II), and Cu(II) complexes are similar and have a saddle-shape configuration. The metal ions have square planar coordination and are located almost in the center of the N(2)O(2) square. The average M-N bond lengths are longer than M-O ones by 0.014 and 0.034 for the Ni(II) and Cu(II) complexes respectively, while in the Pd(II) complex, M-O is longer than M-N by 0.029 . The average chelate angles N-M-O in the complexes are: N-Ni-O 95.12A degrees; N-Pd-O 95.68A degrees; N-Cu-O 93.88A degrees.