Furanyl bis(indolyl)methane as a palladium ion-selective chromogenic agent.

The colorless solution of furan-2-yl bis(indolyl)methane (BIM) is newly revealed to work as a palladium (Pd 2+ ) ion-selective chromogenic agent by turning orange. 5-( N -Methyl- N -phenyl-aminomethyl)-furan-2-yl BIM could be synthesized from 5-chloromethylfurfural as a biorenewable feedstock via one-pot and double functionalization, and a mixture of its solution and Pd 2+ ions showed the highest absorbance at 465 nm in UV-Vis analysis. On the other hand, other metal ions (Cu 2+ , Cr 2+ , Cr 3+ , Fe 2+ , Fe 3+ , Ni 2+ , Zn 2+ , In 2+ , Pt 2+ , or Ce 3+ ) exhibited no response.