A number of unanswered questions occurred to us upon reading a communication by Yam and Kai (ref. ) which had reported optical sensing properties of a boronic-acid-appended ReI complex for saccharides. Careful re-examination has disclosed that the pKa-value proposed by them (5.9) is wrong and that the saccharide-binding mode at pH above the pKa is totally different from that at pH below the pKa. The absorption spectral change, which reflects an sp2-to-sp3 boron hybridisation change induced by the saccharide complexation, was observed only at pH below the pKa, and the CD band, which reflects the formation of 1∶1 cyclic complexes, appeared only at pH above the pKa. The results imply that the optimum pH should be carefully selected for the precise optical sensing of saccharides.
No takes yet. Share an insight, caveat, or question.
Mizuno et al. (2000) studied this question.
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: