Amine bis(phenolate) ligands synthesis can be easily prepared by the reaction of a substituted 2-(bromomethyl)phenol, a substituted phenol, potassium carbonate, triethylamine and the appropriate amine to form the desired compounds in high yields and purities. A series of amine bis(phenolate) ligand precursors with group 4 metals and aluminum complexes have been prepared, characterized by single-crystal X-ray diffraction, and tested for ring opening polymerisation of £`-caprolactone. Group 4 metals complexes which are shown to be active catalysts for the ROP of £`-caprolactone with excellent conversions and polydispersities. All aluminum compounds as four-coordinate aluminum methyl complexes show excellent catalytic activity toward the ring opening polymerization of £`-caprolactone in the presence of benzyl alcohol. And amine bis(phenolate)s ligand ([tert-ButylONO]2-) bond cleavage with zirconium and hafnium complexes that have been prepared, characterized by single-crystal X-ray diffraction. Another zirconium complexes of dianionic amine bis(phenolate) ligands have been synthesized, their X-ray structures solved, and their activity as 1-hexene polymerization catalysts study. Upon treatment with B(C6F5)3, a series of pentacoordinate [ONO]Zr(CH2Ph)2 complex, having no extra donor group, shows only poor activity as a polymerization catalyst. Final reaction of diamine-bis(phenol) ligands containing a mixture of [i-PropylONO]Ti(OiPr)2 in dry THF under RT without exclusion of air and moisture gives {[i-PropylONO]TiO}3 (characterised by X-ray crystallography) is hydrolysed with H2O.