Abstract Tetra-coordinated diacetoxy-boron Schiff base derivatives of the type (AcO)2B(SB) (where SB− is the anion of the corresponding monofunctional bidentate Schiff base, SBH) have been synthesized in almost quantitative yields and in a state of sufficient purity by the equimolar ratio reactions of boric acid and Schiff bases in acetic anhydride medium. Even on mixing the reactants in higher molar ratio only 1:1 derivatives could be isolated. On the basis of elemental analyses, molecular weight determinations and conductance measurements and infrared and proton magnetic resonance spectra, the possible structures for the resulting new derivatives have been indicated.