Complexes of benzene-1,2-diol Mannich bases. I - Novel hexacoordinate zwitterionic silicon(IV) complexes

This paper reports the synthesis and characterization of a number of novel silicon(IV) complexes with a range of mono-Mannich bases of benzene-1,2-diol. Mannich bases of general structure 3-(dialkylaminomethyl) benzene-1,2-diol form zwitterionic 6-coordinate tris complexes with silicon(IV), eliminating the need for an external counter ion. These complexes exhibit marked differences in their ability to partition between an aqueous and organic phase compared with the analogous tris(benzene-1,2-diol) silicon(IV) complex. Mannich bases of diamines and benzene-1, 2-diol will also complex to silicon; however, they result in more complicated polymeric structures.