Chemistry Databases. Chemistry Databases. Question: 1. The CO adduct of borane, BH3, is a somewhat puzzling compound. Although at first sight it appears to be a trivial Lewis acid – Lewis base adduct, CO is a special type of Lewis base: aside from its σ-donating ability, it has strong π-accepting abilities, and prefers to bind to fragments that are able to support a dual, σ-donation, π-back-donation type interaction. Consequently, it is a ligand typical for electron-rich transition metals, and forms few compounds with main group elements. Computational studies have shown that BH3, aside from being a good Lewis acid, is able to participate in hyperconjugation with the π-antibonding orbital on CO, thus explaining its ability to bind with this ligand. a) define hyperconjugation and negative hyperconjugation. b) identify the original paper reporting the synthesis of H3B-CO and explain why, many years after its observation, the structure of this compound has not yet been determined. This means that, although we know what its structure looks like, and experimental determination of the metric parameters of this structure (bond lengths and angles) has not been accomplished. c) find the calculated length and strength of the B-C bond in H3B-CO, identifying the paper that reports these values.
Question: 2. The transformation shown below was recently observed. This is a rather remarkable transformation, first because such “activation” of small molecules is much more typical of transition metals, and second because ammonia is a notoriously difficult small molecule to activate with any system. Activation is often the first step in the incorporation of small molecules such as ammonia in larger organic molecules such as ammines via catalytic processes. a) define “catalyst”. b) why is ammonia a notoriously difficult small molecule to activate on transition metal systems? c) identify the original paper reporting the above transformation and indicate why T-shaped phosphorus systems have the propensity to activate small molecules. How is the molecule above a T-shaped phosphorus system? d) identify a paper reporting a catalytic transformation on a phosphorus(III) center and outline this catalytic transformation, as well as the catalyst. Note that this needs to be catalysis on a phosphorus center, and not one of the numerous transition metal catalysts incorporating phosphorus.
3. Identify the following:
a) The most recent paper published by a scientist affiliated with the Department of Chemistry at the University of Calgary.
b) The most cited paper by Gary J. Schrobilgen.
c) A paper reporting on the predicted structure of NF5.
Place your order now to enjoy great discounts on this or a similar topic.
People choose us because we provide:
Essays written from scratch, 100% original,
Delivery within deadlines,
Competitive prices and excellent quality,
24/7 customer support,
Priority on their privacy,
Unlimited free revisions upon request, and
Plagiarism free work,