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Formation of Mono Oxo Molybdenum(IV) PNP Pincer Complexes: Interplay between Water and Molecular Oxygen.

ABSTRACT: The synthesis of cationic mono oxo Mo^IV PNP pincer complexes of the type [Mo(PNP^Me-iPr)(O)X]⁺ (X = I, Br) from [Mo(PNP^Me-iPr)(CO)X₂] is described. These compounds are coordinatively unsaturated and feature a strong Mo?O triple bond. The formation of these complexes proceeds via cationic 14e intermediates [Mo(PNP^Me-iPr)(CO)X]⁺ and requires both molecular oxygen and water. ESI MS measurements with ¹⁸O labeled water (H₂ ¹⁸O) and molecular oxygen (¹⁸O₂) indicates that water plays a crucial role in the formation of the Mo?O bond. A plausible mechanism based on DFT calculations is provided. The X-ray structure of [Mo(PNP^Me-iPr)(O)I]SbF₆ is presented.

SUBMITTER: de Aguiar SRMM

PROVIDER: S-EPMC6485545 | biostudies-literature | 2018 Feb

REPOSITORIES: biostudies-literature

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Formation of Mono Oxo Molybdenum(IV) PNP Pincer Complexes: Interplay between Water and Molecular Oxygen.

de Aguiar Sara R M M SRMM Öztopcu Özgür Ö Troiani Anna A de Petris Giulia G Weil Matthias M Stöger Berthold B Pittenauer Ernst E Allmaier Günter G Veiros Luis F LF Kirchner Karl K

European journal of inorganic chemistry 20180212 7

The synthesis of cationic mono oxo MoIV PNP pincer complexes of the type [Mo(PNPMe-iPr)(O)X]+ (X = I, Br) from [Mo(PNPMe-iPr)(CO)X2] is described. These compounds are coordinatively unsaturated and feature a strong Mo≡O triple bond. The formation of these complexes proceeds via cationic 14e intermediates [Mo(PNPMe-iPr)(CO)X]+ and requires both molecular oxygen and water. ESI MS measurements with <su ...[more]

PMID: 31057330

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Synthesis and Characterization of Hydrido Carbonyl Molybdenum and Tungsten PNP Pincer Complexes.

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| S-EPMC6341480 | biostudies-literature

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Carbon dioxide hydrogenation catalysed by well-defined Mn(i) PNP pincer hydride complexes.

Project description:The catalytic reduction of carbon dioxide is of great interest for its potential as a hydrogen storage method and to use carbon dioxide as C-1 feedstock. In an effort to replace expensive noble metal-based catalysts with efficient and cheap earth-abundant counterparts, we report the first example of Mn(i)-catalysed hydrogenation of CO2 to HCOOH. The hydride Mn(i) catalyst [Mn(PNPNH-iPr)(H)(CO)2] showed higher stability and activity than its Fe(ii) analogue. TONs up to 10 000 and quantitative yields were obtained after 24 h using DBU as the base at 80 °C and 80 bar total pressure. At catalyst loadings as low as 0.002 mol%, TONs greater than 30 000 could be achieved in the presence of LiOTf as the co-catalyst, which are among the highest activities reported for base-metal catalysed CO2 hydrogenations to date.

| S-EPMC5613213 | biostudies-literature

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