Catalytic Silylation of Dinitrogen by a Family of Triiron Complexes

Ricardo B Ferreira; Brian J Cook; Brian J Knight; Vincent J Catalano; Ricardo García-Serres; Leslie J Murray

doi:10.1021/acscatal.8b02021

Catalytic Silylation of Dinitrogen by a Family of Triiron Complexes

ACS Catal. 2018 Aug 3;8(8):7208-7212. doi: 10.1021/acscatal.8b02021. Epub 2018 Jul 19.

Authors

Ricardo B Ferreira¹, Brian J Cook¹, Brian J Knight¹, Vincent J Catalano², Ricardo García-Serres³, Leslie J Murray¹

Affiliations

¹ Center for Catalysis and Florida Center for Heterocyclic Chemistry, Department of Chemistry, University of Florida, Gainesville, FL 32611, USA.
² Department of Chemistry, University of Nevada, Reno, NV 89557, USA.
³ Université Grenoble Alpes, CNRS, CEA, BIG, LCBM (UMR 5249), F-38054 Grenoble, France.

Abstract

A series of triiron complexes supported by a tris(β-diketiminate)cyclophane (L ^3- ) catalyze the reduction of dinitrogen to tris(trimethylsilyl)amine using KC₈ and Me₃SiCl. Employing Fe₃Br₃ L affords 83 ± 7 equiv. NH₄ ⁺/complex after protonolysis, which is a 50% yield based on reducing equivalents. The series of triiron compounds tested evidences the subtle effects of ancillary donors, including halides, hydrides, sulfides, and carbonyl ligands, and metal oxidation state on N(SiMe₃)₃ yield, and highlight Fe₃(μ₃-N)L as a common species in product mixtures. These results suggest that ancillary ligands can be abstracted with Lewis acids under reducing conditions.

Keywords: N2 reduction; N2 silylation; iron clusters; multinucleating ligand; trinuclear clusters.

Grants and funding

R01 GM123241/GM/NIGMS NIH HHS/United States