Synthesis of novel NHC-based transition metal complexes of Pd(II), Au(I), Cu(I) and Ir(III) with pendant 1,2,3-triazole group for remediation of rhodamine B

Abstract

The transition metal-NHC complexes presented here were all created by us. For instance, A bidentate ligand, [L1-H(Br)] having 1-methyl imidazolium salt, using for N-heterocyclic carbene as precursor, connected to a pendant triazole moiety via methylene bridge has been synthesized via ‘CuAAC’ or ‘Click’ reaction. Imidazolium salt, [L1-H(PF6)] with a non-coordinating anion PF6 has been prepared via anion exchange of [L1-H(Br)] with NH4PF6. Reaction of [L1-H(PF6)] with half an equivalent of Ag2O yielded the Ag(I)–NHC complex [(L1)2Ag](PF6). This Ag(I)–NHC complex is shown to be an excellent carbene transfer agent to other transition metals, both linear and non-linear, when reacted with appropriate equivalents of metal precursors to give variety of organometallic metal-NHC complexes via transmetallation. The compound [(L1)IrCl(Cp*)](PF6) has been applied for the remediation of a water pollutant rhodamine B dye from wastewater. The results of this study also provide good opportunities for organic synthesis in future research.