Synthesis and characterisation of a new mixed [Si(IV), Al(III)] μ-oxo-isopropoxide and its acid complexes

Abstract

Reaction of dimethyldiacetoxysilane with aluminium isopropoxide was carried out in 1 : 2 molar ratio in refluxing cyclohexane and a mixed [Si(IV), Al(III)] μ-oxo-isopropoxide of the composition Me 2SiO 2Al 2(OPr i ) 4 was isolated. This compound was characterised by elemental analysis and IR and NMR spectral studies. The tertiary butanol derivative, Me 2SiO 2Al 2(OBu t ) 4, was prepared by alcoholysis. Reactions of this mixed [Si(IV), Al(III)] μ-oxo-isopropoxide with monobasic bidentate carboxylic acids, such as trans-cinnamic acid (HCA) and dihydrocinnamic acid (HDCA) and with dibasic tridentate carboxylic acids such as salicylic acid (H 2SA) and benzilic acid (H 2BA) were also studied. Products of the type Me 2SiO 2Al 2(OPr i ) 4- n (L) n [where HL = trans-cinnamic acid (HCA), dihydrocinnamic acid (HDCA) and n = 1,2,3 or 4] and Me 2SiO 2Al 2(OPr i ) 4-2 n (L) n [where H 2L = salicylic acid (H 2SA), benzilic acid (H 2BA) and n = 1 or 2] were isolated and characterised by elemental and spectral studies.