864962-41-4

Upstream product

• 86336-41-6 2-(2-{N-[2-(2-hydroxyethoxy)ethyl]phenylamino}ethoxy)ethanol 
• 864962-40-3 4-{bis-[2-(2-hydroxyethoxy)ethyl]amino}benzaldehyde 
• 98-59-9 p-toluenesulfonyl chloride 

Downstream Products

• 864962-42-5 (C₆H₃CH₂)4(OCH₂CH₂OCH₂CH₂N(C₆H₄CHO)CH₂CH₂OCH₂CH₂O)2 

Relevant academic research and scientific papers

A highly selective fluorescent molecular sensor for potassium based on a calix[4]bisazacrown bearing boron-dipyrromethene fluorophores

The synthesis of a ditopic fluorescent sensor for cations associating a 1,3 alternate calix[4]bisazacrown-5 as an ionophore and substituted boron-dipyrromethene dyes as fluorophores is reported. Photophysical studies revealed that in medium and high polarity solvents an efficient charge transfer (CT) reaction occurs in the excited state leading to a dual emission and a strong quenching of fluorescence. This CT process is either totally suppressed by amino group protonation or hampered by cation complexation; in both cases, a strong fluorescence enhancement is observed. This "switching-on" of the emission is more pronounced when two cations are coordinated. The stability constants of complexes with sodium, potassium, caesium, calcium and barium cations were measured in acetonitrile and ethanol. The system shows a high sensitivity and selectivity for potassium over other metal ions. A test under physiological conditions was successfully achieved. The Royal Society of Chemistry and the Centre National de la Recherche Scientifique 2005.