1299464-58-6Relevant articles and documents
Recognition, Sensing, and Trapping of Bicarbonate Anions with a Dicationic meso-Bis(benzimidazolium) Calix[4]pyrrole
Mulugeta, Endale,He, Qing,Sareen, Divya,Hong, Seong-Jin,Oh, Ju Hyun,Lynch, Vincent M.,Sessler, Jonathan L.,Kim, Sung Kuk,Lee, Chang-Hee
, p. 1008 - 1020 (2017)
A meso-aryl calix[4]pyrrole derivative bearing benzimidazolium groups at the two diametrical meso positions was synthesized. The receptor acts as an effective host for the bicarbonate anion at concentrations as low as 4 nM. A change in fluorescence response was observed under conditions of fluorescence dye displacement when this functionalized calix[4]pyrrole was exposed to the HCO3 – anion. Tests with various carbonated drinks revealed its ability to function as an easy-to-use sensor for dissolved CO2, as monitored through the bicarbonate anion concentration. Depending on the specific choice of conditions, recrystallization of the calix[4]pyrrole receptor in the presence of Cs2CO3 and methanol yielded crystals of either the HCO3 – anion complex or methyl carbonate (CH3OCO2 –), a normally difficult-to-access species whose formation under non-forcing equilibrium conditions is ascribed to trapping by the calix[4]pyrrole receptor. The present system thus provides a recognition-based approach to the chemical capture of hydrated, anionic forms of CO2. CO2 is intimately associated with life, both as a building block for carbohydrate synthesis and as the end product of aerobic respiration. It is also key to maintaining the pH of waterways and remains a topic of intense ongoing debate involving climate change. The central nature of CO2 in the chemical world and beyond provides an incentive to develop easy-to-use “tools” to capture, sense, and chemically “fix” CO2 and its hydrated forms (e.g., HCO3 –). Here, we report a dicationic meso-bis(benzimidazolium) calix[4]pyrrole that works to capture CO2 by modulating the HCO3 –/CO2 balance (including in carbonated beverages) and acts as a HCO3 – sensor (at concentrations as low as 4 nM) under solution-phase indicator displacement assay conditions. It also promotes the conversion of hydrated CO2 into methyl carbonate (CH3OCO2 –) under near-neutral conditions by stabilizing this normally unstable mono-ester species in bound form. The chemistry appears generalizable to other related host systems. A synthetic dicationic meso-bis(benzimidazolium) calix[4]pyrrole permits the sensing and chemical capture of CO2 in its hydrated forms.
Synthesis and evaluation of sensitive coumarin-based fluorogenic substrates for discovery of α-N-acetyl galactosaminidases through droplet-based screening
Chen, Hong-Ming,Nasseri, Seyed Amirhossein,Rahfeld, Peter,Wardman, Jacob F.,Kohsiek, Maurits,Withers, Stephen G.
supporting information, p. 789 - 793 (2021/02/09)
As part of a search for a substrate for droplet-based microfluidic screening assay of α-N-acetylgalactosaminidases, spectral and physical characteristics of a series of coumarin derivatives were measured. From among these a new coumarin-based fluorophore, Jericho Blue, was selected as having optimal characteristics for our screen. A reliable method for the challenging synthesis of coumarin glycosides of α-GalNAc was then developed and demonstrated with nine examples. The α-GalNAc glycoside of Jericho Blue prepared in this way was shown to function well under screening conditions.
