Dinitrogen Cleavage by a Diniobium Tetrahydride Complex: Formation of a Nitride and Its Conversion into Imide Species

Akagi, Fumio; Matsuo, Tsukasa; Kawaguchi, Hiroyuki

doi:10.1002/anie.200703336

Cited by 161 publications

(118 citation statements)

References 38 publications

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“…[38][39][40]42,44,46,47,51,52] A few experimental studies showed that a cooperative N 2 activation may even lead to complete N-N bond cleavage. [53][54][55] Notably, iron (a late metal) is present in all three nitrogenase enzyme types, and also the industrial Haber-Bosch process uses iron-based catalysts for N 2 reduction. As mentioned above, due to the inefficient π-backbonding late metal N 2 complexes typically achieve only a moderate N-N weakening, but apparently, strong activation is not necessarily a requirement for nitrogen fixation.…”

Section: Special Issuementioning

confidence: 99%

Late Metal Scaffolds that Activate Both, Dinitrogen and Reduced Dinitrogen Species N_xH_y

Köthe

Limberg

2014

Zeitschrift anorg allge chemie

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Abstract. In the context of biological nitrogen fixation, the question whether molybdenum or iron is the site for substrate binding and reduction is still discussed controversially. Therefore, the development of relevant model compounds containing early or late transition metals is essential in understanding the nature and behavior of intermediates bound to the FeMo-cofactor. Ligated early transition metal atoms are known to strongly activate N 2 and mediate its cleavage, but the resulting complexes contain metal-nitrogen bonds, which often elude

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Section: Special Issuementioning

confidence: 99%

Late Metal Scaffolds that Activate Both, Dinitrogen and Reduced Dinitrogen Species N_xH_y

Köthe

Limberg

2014

Zeitschrift anorg allge chemie

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“…15 The Nb-H elongation in the extended 18 while a bridging (Nb-H-Nb) separation is in the range of 1.8-2.12Å. 19,20 Of course, the higher n is in NbH n , the larger will be in general the number of near Nb-H separations. The histograms show a clear gap between a first group of Nb-H separations of 1.70-1.94Å (but for NbH 6 there is a single Nb-H separation at 2.1Å), and the next longer group, of 2.60-3.56Å.…”

Section: Interatomic Separations and Coordination Number As N Varimentioning

confidence: 99%

“…In Fig. S1 in Supplementary Material, 17 we show a selection of these [18][19][20] and we note that in these systems, hydrogen is terminally bonded to niobium, and also bridging two niobiums. X-ray determined crystal structures do not locate hydrogens reliably, but neutron diffraction experiments (less plentiful, of course) do so; we then see Nb-H separations of ∼1.80Å for terminal Nb-H, and 1.9-2.0Å for bridging hydrogens.…”

Section: Introductionmentioning

confidence: 99%

Theoretical study of the ground-state structures and properties of niobium hydrides under pressure

et al. 2013

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As part of a search for enhanced superconductivity, we explore theoretically the ground-state structures and properties of some hydrides of niobium over a range of pressures and particularly those with significant hydrogen content. A primary motivation originates with the observation that under normal conditions niobium is the element with the highest superconducting transition temperature (T c ), and moreover some of its compounds are metals again with very high T c 's. Accordingly, combinations of niobium with hydrogen, with its high dynamic energy scale, are also of considerable interest. This is reinforced further by the suggestion that close to its insulator-metal transition, hydrogen may be induced to enter the metallic state somewhat prematurely by the addition of a relatively small concentration of a suitable transition metal. Here, the methods used correctly reproduce some ground-state structures of niobium hydrides at even higher concentrations of niobium. Interestingly, the particular stoichiometries represented by NbH 4 and NbH 6 are stabilized at fairly low pressures when proton zero-point energies are included. While no paired H 2 units are found in any of the hydrides we have studied up to 400 GPa, we do find complex and interesting networks of hydrogens around the niobiums in high-pressure NbH 6 . The Nb-Nb separations in NbH n are consistently larger than those found in Nb metal at the respective pressures. The structures found in the ground states of the high hydrides, many of them metallic, suggest that the coordination number of hydrogens around each niobium atom grows approximately as 4n in NbH n (n = 1-4), and is as high as 20 in NbH 6 . NbH 4 is found to be a plausible candidate to become a superconductor at high pressure, with an estimated T c ∼ 38 K at 300 GPa.

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“…These values can be compared to those found in the rare examples of previously reported imido-bridged diuranium(V) complexes (2.387(5)-2.078 (5) ). [16] Thef ormation of imide complexes from the alkylation of nucleophilic bridging nitrides has been reported [17] but did not lead to valence disproportionation. In contrast, the alkylation of 1 promotes the disproportionation of the metal center, thus leading to the transformation of two U IV cations into aU V and aU III complex.…”

mentioning

confidence: 97%

Facile CO Cleavage by a Multimetallic CsU₂ Nitride Complex

et al. 2016

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Uranium nitrides are important materials with potential for application as fuels for nuclear power generation, and as highly active catalysts. Molecular nitride compounds could provide important insight into the nature of the uranium-nitride bond, but currently little is known about their reactivity. In this study, we found that a complex containing a nitride bridging two uranium centers and a cesium cation readily cleaved the C≡O bond (one of the strongest bonds in nature) under ambient conditions. The product formed has a [CsU2 (μ-CN)(μ-O)] core, thus indicating that the three cations cooperate to cleave CO. Moreover, the addition of MeOTf to the nitride complex led to an exceptional valence disproportionation of the CsU(IV) -N-U(IV) core to yield CsU(III) (OTf) and [MeN=U(V) ] fragments. The important role of multimetallic cooperativity in both reactions is illustrated by the computed reaction mechanisms.

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Dinitrogen Cleavage by a Diniobium Tetrahydride Complex: Formation of a Nitride and Its Conversion into Imide Species

Cited by 161 publications

References 38 publications

Late Metal Scaffolds that Activate Both, Dinitrogen and Reduced Dinitrogen Species N_xH_y

Late Metal Scaffolds that Activate Both, Dinitrogen and Reduced Dinitrogen Species N_xH_y

Theoretical study of the ground-state structures and properties of niobium hydrides under pressure

Facile CO Cleavage by a Multimetallic CsU₂ Nitride Complex

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Dinitrogen Cleavage by a Diniobium Tetrahydride Complex: Formation of a Nitride and Its Conversion into Imide Species

Cited by 161 publications

References 38 publications

Late Metal Scaffolds that Activate Both, Dinitrogen and Reduced Dinitrogen Species NxHy

Late Metal Scaffolds that Activate Both, Dinitrogen and Reduced Dinitrogen Species NxHy

Theoretical study of the ground-state structures and properties of niobium hydrides under pressure

Facile CO Cleavage by a Multimetallic CsU2 Nitride Complex

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Late Metal Scaffolds that Activate Both, Dinitrogen and Reduced Dinitrogen Species N_xH_y

Late Metal Scaffolds that Activate Both, Dinitrogen and Reduced Dinitrogen Species N_xH_y

Facile CO Cleavage by a Multimetallic CsU₂ Nitride Complex