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Abstract Reaction of (P)AuOTf [P=P(t‐Bu)2o‐biphenyl] with indenyl‐ or 3‐methylindenyl lithium led to isolation of gold η1‐indenyl complexes (P)Au(η1‐inden‐1‐yl) (1 a) and (P)Au(η1‐3‐methylinden‐1‐yl) (1 b), respectively, in >65 % yield. Whereas complex1 bis static, complex1 aundergoes facile, degenerate 1,3‐migration of gold about the indenyl ligand (ΔG≠153K=9.1±1.1 kcal/mol). Treatment of complexes1 aand1 bwith (P)AuNTf2led to formation of the corresponding cationic bis(gold) indenyl complexestrans‐[(P)Au]2(η1,η1‐inden‐1,3‐yl) (2 a) andtrans‐[(P)Au]2(η1,η2‐3‐methylinden‐1‐yl) (2 b), respectively, which were characterized spectroscopically and modeled computationally. Despite the absence of aurophilic stabilization in complexes2 aand2 b, the binding affinity of mono(gold) complex1 atoward exogenous (P)Au+exceed that of free indene by ~350‐fold and similarly the binding affinity of1 btoward exogenous (P)Au+exceed that of 3‐methylindene by ~50‐fold. The energy barrier for protodeauration of bis(gold) indenyl complex2 awith HOAc was ≥8 kcal/mol higher than for protodeauration of mono(gold) complex1 a.
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Di(indenyl)beryllium
Abstract The bonding in beryllocene, [BeCp2], took decades to establish, owing to its unexpected mixed hapticity structure (i.e., [Be(η5‐Cp)(η1‐Cp)]). Beryllium complexes containing the indenyl ligand, which is a close relative of the cyclopentadienyl anion, but which is also known to exhibit its own bonding peculiarities (e.g., facile η5⇄ η3shifts), have remained unknown. Standard metathetical approaches to their synthesis (e.g., with K[Ind′] + BeX2in an ether solvent) give rise to intractable oils from which nothing identifiable can be isolated. In contrast, mechanochemical preparation, involving the solvent‐free grinding of BeBr2and potassium indenides, leads to the production of discrete (indenyl)beryllium complexes, including [Be(C9H7)2] (1) and [Be{1,3‐(SiMe3)2C9H5}Br] (2). The former displays η5/η1‐coordinated ligands in the solid state, but DFT calculations indicate that an η5/η5‐conformation is less than 5 kcal mol−1higher in energy.
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- Award ID(s):
- 1665327
- PAR ID:
- 10305151
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Angewandte Chemie International Edition
- Volume:
- 60
- Issue:
- 39
- ISSN:
- 1433-7851
- Format(s):
- Medium: X Size: p. 21174-21178
- Size(s):
- p. 21174-21178
- Sponsoring Org:
- National Science Foundation
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