Controlled Sol-Gel Hydrolysis for Synthesis and Characterization of Χ-Al2O3 Nano-Powder Using New Class of Precursors of Bis (N Phenylsalicylideneiminato) Aluminum(III)-Di-(μ-Isopropoxo)-Di-Isopropoxo Aluminum(III) Modified By Mono-Carboxylic Acids

Reactions of bis(N-phenylsalicylideneiminato)aluminum(III))-di-(μ- isopropoxo)-di-isopropoxoaluminum (III) with mono-carboxylic acids yield product of the type [C6H4O{CH=N(C6H5)}]2A1(μ-OPri)2Al(OOCR) (OPri)2–n [where R=CH3, C2H5, C3H7 and n=1 or 2). Progress of the reactions was monitored by estimating liberated 2-propanol in benzene-2-propanol azeotrope by oxidimetric method. All the yellow foamy solid products are soluble in common organic solvents. They were characterized by elemental analyses, FT-IR and (1H, 13C and 27Al) NMR spectral studies. Molecular weight measurements in refluxing anhydrous benzene indicate their binuclear nature. Sol-gel hydrolysis of [C6H4O{CH=N(C6H5)}]2Al(μ-OPri)2Al(OPri)2] (A), and representative compounds [C6H4O{CH=N(C6H5)}]2Al(μ- OPri)2Al(OOCCH3)(OPri)] (1) and [C6H4O{CH=N(C6H5)}]2Al(μ- OPri)2Al(OOCCH3)2] (2) followed by sintering at 600° C yielded cubic primitive phase of nano-crystallites of χ-Al2O3 [JCPDF # 040880] in all the cases, as reflected by their powder X-ray diffraction pattern. The IR, SEM and EDX studies also support the formation of the transition alumina.