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.
more »
« less
Toward Antikekulene: Angular 1,2-Di-, 2,3-Di-, and 1,2,15,16-Tetrachloro[6]phenylene
- Award ID(s):
- 1301346
- PAR ID:
- 10081636
- Date Published:
- Journal Name:
- Synlett
- Volume:
- 25
- Issue:
- 17
- ISSN:
- 0936-5214
- Page Range / eLocation ID:
- 2429 to 2433
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
More Like this
-
-
Thorp, Holden (Ed.)Ancestral metabolic processes involve the reversible oxidation of molecular hydrogen by hydrogenase. Extant hydrogenase enzymes are complex, comprising hundreds of amino acids and multiple cofactors. We designed a 13–amino acid nickel-binding peptide capable of robustly producing molecular hydrogen from protons under a wide variety of conditions. The peptide forms a di-nickel cluster structurally analogous to a Ni-Fe cluster in [NiFe] hydrogenase and the Ni-Ni cluster in acetyl-CoA synthase, two ancient, extant proteins central to metabolism. These experimental results demonstrate that modern enzymes, despite their enormous complexity, likely evolved from simple peptide precursors on early Earth.more » « less
-
Natural Human-Robot interaction (HRI) attracts considerable interest in letting robots understand the users’ emotional state. This paper demonstrates a method to introduce the affection model to the robotic system’s conversational agent to provide natural and empathetic HRI. We use a large-scale pre-trained language model and fine-tune it on a dialogue dataset with empathetic characteristics. Based on existing studies’ progress, we extend the current method and enable the agent to perform advanced sentiment analysis using the affection model. This dialogue agent will allow the robot to provide natural response along with emotion classification and the estimations of arousal and valence level. We evaluate our model using different metrics, comparing it with the recent studies and showing its emotion detection capacity.more » « less
An official website of the United States government

