2-(Naphthalen-2-yl)-1,2,3,4-tetrahydroquinazoline-2-carbaldehyde Oxime and Co(III) and Ni(II) Complexes of Tridentate Ligand Containing Oxime, Imine and Amine Donor Groups: Syntheses, Characterisation and Thermal Properties.

A novel 1,2,3,4-tetrahydroquinazoline oxime was synthesised from a condensation reaction of 2-(naphthalen-2-yl)-2-oxoacetaldehyde oxime with 2-aminobenzylamine. Subsequently, a-imine oxime complexes of this compound that formed with Co(III) and Ni(II) metal ions were obtained. All structures were characterised by spectral methods (FT-IR, nmr, AAS, mass), elemental analysis, thermal analyses, magnetic susceptibility and molar conductivity. The analyses confirmed the following molecular formulae: [Co(L)2]Cl • C2H5OH • 0,5H2O and [Ni(HL)2]Cl2. The Co(III) complex is diamagnetic. Magnetic susceptibility measurements revealed octahedral geometry for the Co(III) and Ni(II) complexes. In the complexes, the chloride ion was found to be noncoordinated to the metal ions as confirmed by conductivity measurements. The NMR spectra of the Co(III) complex confirmed the presence ofethanol in the Co(III) complex. The experimental results of TG-DTA showed that the Co(III) complex contained ethanol and crystal water in the first two stages. The end of the thermal decomposition of the complexes yielded a final product of a metal oxide.