A Terminal Osmium(IV) Nitride: Ammonia Formation and Ambiphilic Reactivity. Issue 38 (16th August 2016)

• Record Type: Journal Article
• Authors: Schendzielorz, Florian S.; Finger, Markus; Volkmann, Christian; Würtele, Christian; Schneider, Sven
• Is Part Of: Angewandte Chemie international edition. Volume 55:Issue 38(2016)
• Page Start: 11417
• Page End: 11420
• Publication Date: 2016-08-16
• Subjects: ammonia -- dihydrogen -- nitride -- nitrogen fixation -- osmium; Chemistry -- Periodicals; 540
• DOI: 10.1002/anie.201604917
• Languages: English
• ISSNs: 1433-7851

Abstract

Abstract: Low‐valent osmium nitrides are discussed as intermediates in nitrogen fixation schemes. However, rational synthetic routes that lead to isolable examples are currently unknown. Here, the synthesis of the square‐planar osmium(IV) nitride [OsN(PNP)] (PNP=N(CH2 CH2 P(tBu)2 )2 ) is reported upon reversible deprotonation of osmium(VI) hydride [Os(N)H(PNP)] + . The Os IV complex shows ambiphilic nitride reactivity with SiMe3 Br and PMe3, respectively. Importantly, the hydrogenolysis with H2 gives ammonia and the polyhydride complex [OsH4 (HPNP)] in 80 % yield. Hence, our results directly demonstrate the role of low‐valent osmium nitrides and of heterolytic H2 activation for ammonia synthesis with H2 under basic conditions. Abstract : The first rational synthesis for an isolable osmium(IV) nitride is reported. The title compound [Os(N){N(CH2 CH2 P t Bu2 )2 }] shows ambiphilic nitride reactivity and gives ammonia upon hydrogenolysis with H2 in high yield. These results emphasize the role of low‐valent osmium nitrides and H2 heterolysis for nitrogen fixation strategies.