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Nitrogen (N2) fixation by nature, which is a crucial process for the supply of bio-available forms of nitrogen, is performed by nitrogenase. This enzyme uses a unique transition-metal–sulfur–carbon cluster as its active-site co-factor ([(R-homocitrate)MoFe7S9C], FeMoco)1,2, and the sulfur-surrounded iron (Fe) atoms have been postulated to capture and reduce N2 (refs. 3–6). Although there are a few examples of synthetic counterparts of the FeMoco, metal–sulfur cluster, which have shown binding of N2 (refs. 7–9), the reduction of N2 by any synthetic metal–sulfur cluster or by the extracted form of FeMoco10 has remained elusive, despite nearly 50 years of research. Here we show that the Fe atoms in our synthetic [Mo3S4Fe] cubes11,12 can capture a N2 molecule and catalyse N2 silylation to form N(SiMe3)3 under treatment with excess sodium and trimethylsilyl chloride. These results exemplify the catalytic silylation of N2 by a synthetic metal–sulfur cluster and demonstrate the N2-reduction capability of Fe atoms in a sulfur-rich environment, which is reminiscent of the ability of FeMoco to bind and activate N2.Iron atoms in a synthetic metal–sulfur cluster can capture nitrogen and catalyse its silylation, demonstrating successful nitrogen reduction by iron atoms in a sulfur-rich environment. [ABSTRACT FROM AUTHOR]

A synthetic protocol was developed for a series of cubane‐type [Mo3S4M] clusters that incorporate halides of first‐row transition metals (M) from Groups 4–10. This protocol is based on the anionic cluster platform [Cp*3Mo3S4]− ([1]−; Cp*=η5‐C5Me5), which crystallizes when K(18‐crown‐6) is used as the counter cation. Treatment of in situ‐generated [1]− with such transition‐metal halides led to the formation of [Mo3S4M] clusters, in which the M/halide ratio gradually changes from 1:2 to 1:1.5 and to 1:1, when moving from early to late transition metals. This trend suggests a tendency for early transition metals to tolerate higher oxidation states and adopt larger ionic radii relative to late transition metals. The properties of the [Mo3S4Fe] cluster 6 a were investigated in detail by using 57Fe Mössbauer spectroscopy and computational methods. Cubic clusters: A synthetic protocol was developed for a series of cubane‐type [Mo3S4M] clusters, based on the anionic cluster platform [Cp*3Mo3S4]−, which incorporate halides of first‐row transition metals (M) from Group 4–10. The M/halide ratio gradually increases from 1:2 to 1:1.5 and to 1:1 upon moving from early to late transition metals. [ABSTRACT FROM AUTHOR]

A synthetic protocol was developed for a series of cubane-type [Mo 3 S 4 M] clusters that incorporate halides of first-row transition metals (M) from Groups 4-10. This protocol is based on the anionic cluster platform [Cp* 3 Mo 3 S 4 ] - ([1] - ; Cp*=η 5 -C 5 Me 5 ), which crystallizes when K(18-crown-6) is used as the counter cation. Treatment of in situ-generated [1] - with such transition-metal halides led to the formation of [Mo 3 S 4 M] clusters, in which the M/halide ratio gradually changes from 1:2 to 1:1.5 and to 1:1, when moving from early to late transition metals. This trend suggests a tendency for early transition metals to tolerate higher oxidation states and adopt larger ionic radii relative to late transition metals. The properties of the [Mo 3 S 4 Fe] cluster 6 a were investigated in detail by using 57 Fe Mössbauer spectroscopy and computational methods., (© 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)