Synthesis of 3,5-bis(phosphonomethyl)benzoic acid and its application as a metal oxide surface bivalent anchor

Article abstract of DOI:10.1016/S0040-4020(99)00062-9

A protected form of 3,5-bis(phosphonomethyl)benzoic acid (Bpb-OH), a metal oxide surface bivalent anchor, has been synthesized, coupled to an amine functionality, deprotected, and shown to bind to metal oxide surfaces. The protected anchor, 3,5-bis(dimethoxyphosphinylmethyl)benzoic acid (Me₄Bpb-OH) was synthesized in 23% yield over four steps, coupled to a proline-chromophore, deprotected with a solution of iodotrimethylsilane (TMSI) in acetonitrile and adsorbed to Tin(IV)-doped indium oxide and nanocrystalline TiO₂ electrodes at surface coverages of 1.5 x 10^-10 mol cm^-2 and 4.9 x 10^-11 mol cm^-2, respectively. Finally, Me₄Bpb-OH was converted to an amino derivative by attaching a diamino butane linker.