[Fe(bpy)Cl₃X][bpy H] complexes: synthesis, characterization and theoretical studies towards visible-light photocatalytic hydroxyethylation of quinoline

Abstract

A series of [Fe(bpy)Cl₃X][bpy·H] (X = Cl, Br, I) complexes were prepared from direct treatment of FeCl₃·6H₂O with 2,2′-bipyridine in the presence of an HX solution. The complexes were characterized by IR, UV–Vis, XRDP, and cyclic voltammetry techniques. Electrochemical studies revealed a possible reduction to form the corresponding Fe⁰ complexes. A single crystal of [Fe(bpy)Cl₄][bpy·H] displayed important H–Cl/Cl–H, H–H, H–C/C–H, and H–N/N–H interactions which were corroborated by a Hirshfeld surface analysis as well as MEP, QTAIM, and NCI studies, and complemented by HOMO/LUMO calculations at the B3LYP/cc-pVDZ + LANL2DZ level. In addition, the complexes displayed catalytic activity for the visible-light-driven the formation of 1-quinolin-4-yl-ethanol from quinoline under acidic conditions.

KEYWORDS:

• Iron complex
• bipyridine
• hydroxyethylation

Disclosure statement

No potential conflict of interest was reported by the authors.

Acknowledgments

The authors thank N. Zavala, A. Nuñez, L. Triana, and M.C. Martínez for the technical support.

Additional information

Funding

Funded by CONACYT (Project No. A1-S-18230 and fellowship for Z.G.R.M., CVU: 860116).