A new way of modifying aluminum sec-butoxide (Al(OBus)(3)) is proposed. Thi
s synthesis is carried out by reacting Al(OBus)(3) dissolved in tetrahydrof
uran with an unsaturated acid, viz. acrylic acid.
The structure evolution of Al(OBus)(3) with increasing acrylic acid amounts
is investigated by infrared, H-1 NMR, C-13 NMR, and Al-27 NMR spectroscopi
es and viscosity measurements. Information obtained suggests that the excha
nge reaction occurring between butoxy groups and acrylate ligands is stoppe
d for an acid/alkoxide molar ratio within the range 1.6-1.7. This value lea
ds us to assume that the dominant trimeric species of precursor is preserve
d after modification. Moreover, Al-27 NMR analysis only reveals the presenc
e of hexacoordinated Al sites in the structure of the modified Al(OBus)(3).
Evidence of the acrylic acid reaction with sec-butanol released during the
alkoxide modification is also proved by the infrared and C-13 NMR data. How
ever the produced ester amount can be considered as negligible.