436084-62-7Relevant academic research and scientific papers
Tuning and dissecting electronic and steric effects in ammonium receptors: Nonactin vs artificial receptors
Chin, Jik,Oh, Jinho,Jon, Sang Yong,Park, Sang Hyun,Walsdorff, Christian,Stranix, Brent,Ghoussoub, Assaad,Lee, Seok Jong,Jei Chung, Hyun,Park, Su-Moon,Kim, Kimoon
, p. 5374 - 5379 (2002)
Ion selective electrodes (ISE) based on three different tripodal receptors (5, 6, and 7) have been investigated for sensing ammonium ion. Each receptor is based on three pyrazole groups that can accept three H-bonds from the bound ammonium ion. The receptor based on 4-bromo-3,5-dimethylpyrazole (6) is the most sensitive with a detection limit for ammonium ion of 2.5 × 10-5 M at pH 8. The detection limits for the receptors based on 2,3-dimethylpyrazole (5) and unsubstitued pyrazole (7) are 1.0 × 10-4 and 2.0 × 10-4 M, respectively. The selectivities of the receptors 5, 6, and 7 for sensing ammonium ion over potassium ion (logKNH4+/K+) are -2.8, -2.3, and -1.7, respectively. In contrast, the detection limit and the selectivity of a nonactin-based ISE are 2.2 × 10-5 M and -1.3, respectively. Crystallographic studies reveal that 6 accepts three H-bonds from the bound ammonium and singly protonated receptor 5 forms three H-bonds with the bound water molecule.
Synthesis of tripodal and hexapodal pyrazole- and benzimidazole-bearing compounds
Koch, Niklas,Mazik, Monika
, p. 3341 - 3348 (2014/01/06)
The syntheses of eight new tripodal and hexapodal benzimidazole- and pyrazole-bearing compounds, which are all potentially applicable for use as artificial receptors, are described. The prepared compounds contain either bromo-substituted heteroaromatic ri
