Three new colorimetric anion receptors 1–3 were synthesized and characterized. Among them, both 1 and 3 showed good sensitivity and selectivity for discrimination of maleatevs. fumarate or malatevs. tartrate by dramatic colour changes in DMSO or DMSO–H₂O (95 : 5). Thus, both 1 and 3 can be used as optical chemosensors for recognition of maleatevs. fumarate or malatevs. tartrate anion. Besides that, the receptor 1 has also a unique colour change for recognition of either cis-aconitate or trans-aconitate in DMSO, accordingly it can be used for detection of each isomer and discrimination of cis-aconitate from trans-aconitate anion.