TY - JOUR
T1 - Arene-, Chlorido-, and Imido-Uranium Bis and Tris(boryloxide) Complexes
AU - Dan, Xuhang
AU - Du, Jingzhen
AU - Zhang, Shuhan
AU - Seed, John A.
AU - Perfetti, Mauro
AU - Tuna, Floriana
AU - Wooles, Ashley J.
AU - Liddle, Stephen T.
N1 - Publisher Copyright:
© 2024 The Authors. Published by American Chemical Society.
PY - 2024/5/27
Y1 - 2024/5/27
N2 - We introduce the boryloxide ligand {(HCNDipp)
2BO}
− (NBO
Dipp, Dipp = 2,6-di-isopropylphenyl) to actinide chemistry. Protonolysis of [U{N(SiMe
3)
2}
3] with 3 equiv of NBO
DippH produced the uranium(III) tris(boryloxide) complex [U(NBO
Dipp)
3] (1). In contrast, treatment of UCl
4 with 3 equiv of NBO
DippK in THF at room temperature or reflux conditions produced only [U(NBO
Dipp)
2(Cl)
2(THF)
2] (2) with 1 equiv of NBO
DippK remaining unreacted. However, refluxing the mixture of 2 and unreacted NBO
DippK in toluene instead of THF afforded the target complex [U(NBO
Dipp)
3(Cl)(THF)] (3). Two-electron oxidation of 1 with AdN
3 (Ad = 1-adamantyl) afforded the uranium(V)-imido complex [U(NBO
Dipp)
3(NAd)] (4). The solid-state structure of 1 reveals a uranium-arene bonding motif, and structural, spectroscopic, and DFT calculations all suggest modest uranium-arene δ-back-bonding with approximately equal donation into the arene π
4 and π
5 δ-symmetry π* molecular orbitals. Complex 4 exhibits a short uranium(V)-imido distance, and computational modeling enabled its electronic structure to be compared to related uranium-imido and uranium-oxo complexes, revealing a substantial 5f-orbital crystal field splitting and extensive mixing of 5f |m
l,m
s⟩ states and m
j projections. Complexes 1-4 have been variously characterized by single-crystal X-ray diffraction,
1H NMR, IR, UV/vis/NIR, and EPR spectroscopies, SQUID magnetometry, elemental analysis, and CONDON, F-shell, DFT, NLMO, and QTAIM crystal field and quantum chemical calculations.
AB - We introduce the boryloxide ligand {(HCNDipp)
2BO}
− (NBO
Dipp, Dipp = 2,6-di-isopropylphenyl) to actinide chemistry. Protonolysis of [U{N(SiMe
3)
2}
3] with 3 equiv of NBO
DippH produced the uranium(III) tris(boryloxide) complex [U(NBO
Dipp)
3] (1). In contrast, treatment of UCl
4 with 3 equiv of NBO
DippK in THF at room temperature or reflux conditions produced only [U(NBO
Dipp)
2(Cl)
2(THF)
2] (2) with 1 equiv of NBO
DippK remaining unreacted. However, refluxing the mixture of 2 and unreacted NBO
DippK in toluene instead of THF afforded the target complex [U(NBO
Dipp)
3(Cl)(THF)] (3). Two-electron oxidation of 1 with AdN
3 (Ad = 1-adamantyl) afforded the uranium(V)-imido complex [U(NBO
Dipp)
3(NAd)] (4). The solid-state structure of 1 reveals a uranium-arene bonding motif, and structural, spectroscopic, and DFT calculations all suggest modest uranium-arene δ-back-bonding with approximately equal donation into the arene π
4 and π
5 δ-symmetry π* molecular orbitals. Complex 4 exhibits a short uranium(V)-imido distance, and computational modeling enabled its electronic structure to be compared to related uranium-imido and uranium-oxo complexes, revealing a substantial 5f-orbital crystal field splitting and extensive mixing of 5f |m
l,m
s⟩ states and m
j projections. Complexes 1-4 have been variously characterized by single-crystal X-ray diffraction,
1H NMR, IR, UV/vis/NIR, and EPR spectroscopies, SQUID magnetometry, elemental analysis, and CONDON, F-shell, DFT, NLMO, and QTAIM crystal field and quantum chemical calculations.
U2 - 10.1021/acs.inorgchem.3c04275
DO - 10.1021/acs.inorgchem.3c04275
M3 - Article
C2 - 38557081
SN - 0020-1669
VL - 63
SP - 9588
EP - 9601
JO - Inorganic Chemistry
JF - Inorganic Chemistry
IS - 21
ER -