Conversion of N<sub>2</sub> into oxadiazoles promoted by a multinuclear samarium complex.

Shi, Xianghui; Yuan, Qiong; Chen, Yuanjin; Xi, Zhenfeng; Wei, Junnian · Nat Commun · 2025

basic_science · Level V

Where this comes from

Abstract

The nitrogenous compounds play a substantial role in life. Transformation of N<sub>2</sub> into high-value nitrogen-containing organic compounds, not through NH<sub>3</sub>, is of great significance but poses a long-standing challenge. Compared with d-block metals, the derivatization chemistry of rare-earth metal dinitrogen complexes remains elusive. Here we report the single-electron reductions of tetrametallic samarium dinitrogen complex 1 [L<sub>4</sub>Sm<sub>4</sub>N<sub>2</sub>(THF)<sub>2</sub>] (L = [(CH<sub>2</sub>)<sub>5</sub>C(C<sub>4</sub>H<sub>3</sub>N)<sub>2</sub>]<sup>2-</sup>) in THF with dipyrrolide dianion as the ligand, to obtain ionic complexes 2 and 3, [L<sub>4</sub>Sm<sub>4</sub>N<sub>2</sub>]M(THF)<sub>6</sub> (M = K, Na), respectively. Different from 2, 3 could dissolve in Et<sub>2</sub>O to give complex 4 [L<sub>4</sub>Sm<sub>4</sub>N<sub>2</sub>Na(Et<sub>2</sub>O)], featuring a side-on coordination of Na to dinitrogen molecule. When upon extended reaction time, a more nucleophilic complex 5 [L<sub>4</sub>Sm<sub>3</sub>N<sub>2</sub>Na<sub>3</sub>] is achieved. Moreover, further reaction of 5 with many aroyl chlorides to successfully afford corresponding oxadiazole organic compounds from N<sub>2</sub>, facilitated by rare-earth metal [(N<sub>2</sub>)<sup>4-</sup>] unit.