What is the nature of the uranium()-arene bond?
Complexes of the form [U(η 6 -arene)(BH 4 ) 3 ] where arene = C 6 H 6 ; C 6 H 5 Me; C 6 H 3 -1,3,5-R 3 (R = Et, iPr, t Bu, Ph); C 6 Me 6 ; and triphenylene (C 6 H 4 ) 3 were investigated towards an understanding of the nature of the uranium-arene interaction. Density functional theory (DFT) shows th...
Gespeichert in:
Veröffentlicht in: | Chemical science (Cambridge) 2024-01, Vol.15 (5), p.181-1819 |
---|---|
Hauptverfasser: | , , |
Format: | Artikel |
Sprache: | eng |
Schlagworte: | |
Online-Zugang: | Volltext |
Tags: |
Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
|
Zusammenfassung: | Complexes of the form [U(η
6
-arene)(BH
4
)
3
] where arene = C
6
H
6
; C
6
H
5
Me; C
6
H
3
-1,3,5-R
3
(R = Et, iPr,
t
Bu, Ph); C
6
Me
6
; and triphenylene (C
6
H
4
)
3
were investigated towards an understanding of the nature of the uranium-arene interaction. Density functional theory (DFT) shows the interaction energy reflects the interplay between higher energy electron rich π-systems which drive electrostatic contributions, and lower energy electron poor π-systems which give rise to larger orbital contributions. The interaction is weak in all cases, which is consistent with the picture that emerges from a topological analysis of the electron density where metrics indicative of covalency show limited dependence on the nature of the ligand - the interaction is predominantly electrostatic in nature. Complete active space natural orbital analyses reveal low occupancy U-arene π-bonding interactions dominate in all cases, while δ-bonding interactions are only found with high-symmetry and electron-rich C
6
Me
6
. Finally, both DFT and multireference calculations on a reduced, formally U(
ii
), congener, [U(C
6
Me
6
)(BH
4
)
3
]
−
, suggests the electronic structure (
S
= 1 or 2), and hence metal oxidation state, of such a species cannot be deduced from structural features such as arene distortion alone. We show that arene geometry strongly depends on the spin-state of the complex, but that in both spin-states the complex is best described as U(
iii
) with an arene-centred radical.
Complexes of the form [U(η
6
-arene)(BH
4
)
3
] where arene = C
6
H
6
; C
6
H
5
Me; C
6
H
3
-1,3,5-R
3
(R = Et,
i
Pr,
t
Bu, Ph); C
6
Me
6
; and triphenylene (C
6
H
4
)
3
were investigated towards an understanding of the nature of the uranium-arene interaction. |
---|---|
ISSN: | 2041-6520 2041-6539 |
DOI: | 10.1039/d3sc04715f |