Reversible Binding and Reduction of Dinitrogen by a Uranium(III) Pentalene Complex

Abstract

The U(III) mixed-sandwich compound [U(eta-Cp)(eta-C(8)H(4)[Si(i)Pr(3)-1,4](2))] 1 may be prepared by sequential reaction of UI(3) with KCp followed by K(2)[C(8)H(4)[Si(i)Pr(3)-1,4](2)], and has been crystallographically characterized. 1 reacts reversibly with dinitrogen to afford dimeric [[U(eta-Cp)(eta-C(8)H(4)[Si(i)Pr(3)-1,4](2))](2)(mu-eta(2):eta(2)-N(2))] 2, whose X-ray crystal structure reveals a sideways-bound, bridging diazenido (N(2)(2-)) ligand.

A base-free synthetic route to anti-bimetallic lanthanide pentalene complexes

“…In contrast the other europium atom Eu2 is not solvated but interacts with all 8 carbons of the pentalene ring, which folds by 16.1° to accommodate the electropositive centre, as is typical for the structures of mono f-element pentalene compounds. 18,52 This unusual coordination environment for Eu2 is quantified by the ring slippage parameter (−0.268 Å) with its proximal pentalene C 5 -centroid (see ESI † Figure S1 for definition of Δ M−Ct ) which is exceptionally large and negative in comparison to this parameter for Eu1 (0.069 Å), and those for 1 and 3. Pentalene is normally considered as a dianionic ligand in the η 8 and is thus best considered as a subtle interaction attributed to the electron deficiency of Eu2 with respect to Eu1.…”

Activation of Molecular Nitrogen: Coordination, Cleavage and Functionalization of N2 Mediated By Metal Complexes

“…X-ray crystallography revealed the two complexes are isomorphous. The N-N distances are 1.264 (7) (Figure 10 [ 64] This difference is surprising considering these two uranium dinitrogen complexes are isoelectronic, and shows how small structural changes can greatly affect dinitrogen coordination.…”

Barium Dibenzopentalenide as a Main‐Group Metal η8 Complex: Facile Synthesis from 1,4‐Dilithio‐1,3‐butadienes and Ba[N(SiMe3)2]2, Structural Characterization, and Reaction Chemistry

“…[1][2][3] The dianion I is known to coordinate with two metal centers in an h 5 mode, both in cis fashion (Ia) and trans fashion (Ib). [2] The dianion I may also coordinate to a single metal in an h 8 mode (Ic).…”

“…[2] The dianion I may also coordinate to a single metal in an h 8 mode (Ic). [3] For the coordinating mode Ic, the metal center is usually an f-or d-block element. [1][2][3] Main-group metals for the coordinating mode Ic have not been reported to date, owing to the high instability caused by the extreme distortion.…”

“…[3] For the coordinating mode Ic, the metal center is usually an f-or d-block element. [1][2][3] Main-group metals for the coordinating mode Ic have not been reported to date, owing to the high instability caused by the extreme distortion. [4] Much less investigation has been carried out on the dibenzopentalene dianion II (Scheme 1), which is more p-extended than the pentalene dianion I.…”