Recently, neutral organic molecules

Recently, neutral organic molecules which are capable of creating highly directional hydrogen bonding interactions have been
successfully used in the design of novel anion receptors. The
acetate anion plays an important role in biochemistry, environmental, and pharmaceutical science. 9–11 For example, acetate production and oxidation rate have been frequently used because the
acetate anion is considered as an indicator of organic decomposition in marine sediments. 12 A great effort has been made to the
development of sensing devices for AcO ? involving fluorescence
chemosensors, chromogenic chemosensors, 13 and sensors based
on electrochemical devices. 14 Even with these remarkable achieve-
ments, there are many downsides being recognized. Generally, the
recognition of anions are studied in less polar organic solvents 15,16
(e.g. CH 2 Cl 2 , DMSO, CH 3 CN etc.) and sometimes also in the mixture
of protic solvents (e.g. H 2 O, CH 3 CH 2 OH). Normally the acetate
chemosensors will display response to other anions such as fluo-
ride and dihydrogenphosphate, especially the former, 17 but the
sensitivity of our receptor L to the fluoride ion as well as dihydro-
gen phosphate is negligible and does not show any ‘naked-eye’
detectable color.