Synthesis and applications of (5-substituted benzimidazolo)-benzo-15-crown-5 and 4,4′-bis-benzimidazolo-dibenzo-15-crown-5 for the colorimetric detection of Au3+

In the present work, we have reported the synthesis of benzimidazoles functionalized crown ether derivatives of 4-formyl benzo-15-crown-5/4,4 '-diformyl dibenzo-15-crown-5 and substituted diamine pyridine using sulfamic acid as a catalyst in DMSO. These molecules are used for the colorimetric determination of Au3+ selectively among other metal cations such as Fe2+, Co2+, Ni2+, Cu2+, Zn2+, Cd2+, Pb2+, Hg2+, Au3+ and Ag+ ions(.)