Display omitted •Seven ferrocenyl-based unsymmetrical azines 3a–3f and 5a were synthesized under metal-free conditions in good yields.•The compounds 3f and 5a have shown to be excellent multichannel recognition receptors for Hg2+ and Cu2+.•1,1′-disubstituted ferrocene-based azines 3f has higher sensitivity than 1-disubstituted ferrocene-based azines 5a.•Different substituent groups on the phenyl have significant influence on the sensitivity.•The color of the solution containing chemosensor 3f changed from yellow to colorless, upon the addition of Hg2+ and Cu2+ ions. Seven ferrocenyl-based unsymmetrical azines 3a–3f and 5a were synthesized under metal-free conditions in good yields. Ferrocene-based unsymmetrical azines 3f and 5a have shown to be excellent multichannel chemosensors for Hg2+ and Cu2+ ions in aqueous environment. The color of the solution containing chemosensor 3f changed from yellow to colorless, upon the addition of Hg2+ and Cu2+ ions. Quantification of the absorption titration analysis shows that the detection limit was 6.77×10−7M for 3f-Cu2+ and 7.19×10−7M for 3f-Hg2+, respectively. For 5a, the detection limit can reach 1.29×10−7M and 2.40×10−7M for Cu2+ and Hg2+, respectively. Moreover, 1-substituted ferrocene-based unsymmetrical azines 3a–3e with electron-rich, electron-neutral, and electron-deficient aryl groups have significant influence on the sensitivity.