Tungsten and molybdenum dinitrogen complexes supported by a pentadentate tetrapodal phosphine ligand: comparative spectroscopic, electrochemical and reactivity studies
The tungsten dinitrogen complex [W(N 2 )(P Me 2 PP Ph 2 )] ( 2 ) (P Me 2 PP Ph 2 = [2-({bis[3-(diphenylphosphino)propyl]-phosphino}methyl)-2-methylpropane-1,3-diyl]bis(dimethylphosphine)) is synthesized and characterized by X-ray diffraction as well as IR and NMR spectroscopies, showing strong analo...
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Veröffentlicht in: | Dalton transactions : an international journal of inorganic chemistry 2022-04, Vol.51 (16), p.6166-6176 |
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Hauptverfasser: | , , , , , , |
Format: | Artikel |
Sprache: | eng |
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Zusammenfassung: | The tungsten dinitrogen complex [W(N
2
)(P
Me
2
PP
Ph
2
)] (
2
) (P
Me
2
PP
Ph
2
= [2-({bis[3-(diphenylphosphino)propyl]-phosphino}methyl)-2-methylpropane-1,3-diyl]bis(dimethylphosphine)) is synthesized and characterized by X-ray diffraction as well as IR and NMR spectroscopies, showing strong analogies to its molybdenum analogue [Mo(N
2
)(P
Me
2
PP
Ph
2
)] (
1
). Whereas cyclic voltammetry studies indicate very similar redox potentials, detailed electrochemical and IR-spectroelectrochemical investigations reveal characteristic differences between
1
and
2
upon electrochemical oxidation in THF. Protonation of
2
with HBAr
F
(BAr
F
= tetrakis(3,5-bis(trifluoromethyl)-phenyl)borate) leads to the hydrazido(2-) derivative
3
which is spectroscopically characterized as well. In the presence of SmI
2
/H
2
O slightly overstoichiometric conversion of N
2
to ammonia (2.75 equiv.) is observed. Although this is far below the activity of the Mo-complex
1
, it renders
2
the first W complex to produce more than 2 equivalents of NH
3
from N
2
upon addition of protons and reductant.
The tungsten dinitrogen complex [W(N
2
)(P
Me
2
PP
Ph
2
)] is compared to its molybdenum analogue. Detailed (IR-spectro)electrochemical investigations were made. In the presence of SmI
2
/H
2
O the W complex mediates the conversion of N
2
to 2.75 equiv. ammonia. |
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ISSN: | 1477-9226 1477-9234 |
DOI: | 10.1039/d1dt04212b |