Bismetalloporphyrin-based ISE sensitive to fluoroborate

Several mu-oxo-bismetalloporphyrin complexes were synthesized for preparing fluoroborate sensors. The electrode based on mu-oxo-bistetra(p-chlorophenyl)porphinatomanganese(III)] with an optimized membrane composition shows a potentiometric response towards fluoroborate ion over the concentration range from 4.3 x 10(-7) to 1.0 x 10(-1) mol l-1 with a Nernstian slope, a wide working pH range from 5.5 to 12.0 and a fast response time of 30 s. The electrode shows anti-Hofmeister selectivity towards BF4- with respect to common co-existing ions, which is an improvement over methods reported so far. As electroactive materials, several mu-oxo-bismetalloporphyrins with different substituents on the benzene rings were compared for potentiometric response characteristics. The interaction between BF4- and bismetalloporphyrin was investigated using UV/VIS spectrophotometry. The electrode was applied to the determination of fluoroborate in electroplating solutions.