Red and green forms of nickel(II) complexes of schiff bases obtained from 3-methoxysalicylaldehyde and 4-halogenoanilines

Abstract Crystals of two forms were prepared for complexes of the type Ni(3CH 3 OSAL.4YPh) 2 , where YPh denotes a chlorophenyl or bromophenyl. Bis-(N-aryl-3-methoxysalicylideneiminato)nickel(II) is abbreviated as Ni(3CH 3 OSAL.aryl) 2 . The two forms of the chloro-series take a structure similar to that of the corresponding forms of the bromo-series. Since both the forms are paramagnetic with a magnetic moment corresponding to two unpaired electrons, the squareplanar configuration is excluded. The electronic spectrum, together with the magnetic moment, indicates that the green crystals (Form II) consist of associated, polymeric species, in which the nickel(II) ions are six-coordinated. In a similar way, it is concluded that the nickel(II) ions in the red crystals (Form I) are five-coordinated. Possible structures for the two forms are discussed.