Catalysis: Iron-catalyzed Arylation of Alkyl Halides

Submitted by Brad Wile / Ohio Northern University on Fri, 06/09/2017 - 15:34
Description

This LO describes a laboratory experiment in which students generate (in situ) an iron catalyst for the arylation of alkyl halides (Kumada coupling). Students pool data from the class to discern what features lead to successful catalyst systems. GC-MS or GC-FID may be used to quantify the catalytic performance of each system, and results may be expressed as % conversion, with TON/TOF values. Students gain experience proposing reasonable coordination complexes that may be formed from the catalyst precursors, and searching the literature/databases for related compounds/systems.

Investigating the toxicities of metals and identifying cadmium centers in metallothioneins

Submitted by Chantal Stieber / Cal Poly Pomona on Sat, 06/03/2017 - 14:43
Description

This activity was designed as an in-class group activity, in which students begin by using basic principles to predict relative toxicities and roles of metals in biological systems. Students then learn about the structures of metallothioneins using information from the protein data bank (PDB) and 113Cd NMR data. By the end of the activity, students will have analyzed data to identify and determine bonding models and coordination sites for multiple cadmium centers in metallothioneins. It is based on recent literature, but does not require students to have read the papers before class.

Introduction to Agostic Interactions

Submitted by Emma Downs / Fitchburg State University on Sat, 06/03/2017 - 11:59
Description

A brief introduction to agostic interactions and their importance to common organometallic mechanisms such as beta-hydride elimination. Examples of compounds containing these interactions are discussed and compared to familiar molecules such as diborane. Ways to characterize these interactions are also introduced.

Slides are based on the PNAS review Agostic Interactions in Transition Metal Compounds 

Brookheart, Green, and Parkin Proc. Natl. Acad.Sci. 2007, 104(7), 6908-6914

Literature Discussion of R3CH→ SiFR3 Agostic Interactions

Submitted by tgupta / South Dakota State University on Sat, 06/03/2017 - 11:53
Description

The set of questions in this literature discussion activity is intended to engage students in reading and interpreting scientific literature and to develop a clear and coherent understanding of agostic interactions.

Literature Discussion of "A stable compound of helium and sodium at high pressure"

Submitted by Nicole Crowder / University of Mary Washington on Sat, 06/03/2017 - 11:26
Description

This paper describes the synthesis of a stable compound of sodium and helium at very high pressures. The paper uses computational methods to predict likely compounds with helium, then describe a synthetic protocol to make the thermodynamically favored Na2He compound. The compound has a fluorite structure and is an electride with the delocalization of 2e- into the structure.

This paper would be appropriate after discussion of solid state structures and band theory.

The questions are divided into categories and have a wide range of levels.

An ion exchange method to produce metastable wurtzite metal sulfide nanocrystals

Submitted by Janet Schrenk / University of Massachusetts Lowell on Sat, 06/03/2017 - 11:25
Description

In this literature discussion, students use a paper from the literature to explore the synthesis, structure, characterization (powder XRD, EDS and TEM) and energetics associated with the production of a metastable wurtzite CoS phase. Students also are asked define key terms and acronyms used in the paper; identify the goal of the experiments and determine if the authors met their goal. They examine the fundamental concepts around the key crystal structures available.  

 

Quantum Dot Growth Mechanisms

Submitted by Chi / United States Military Academy on Sat, 06/03/2017 - 11:01
Description

This literature article covers a range of topics introduced in a sophomore level course (confinement/particle-in-a-box, spectroscopy, kinetics, mechanism) and would serve as a an end-of-course integrated activity, or as a review activity in an upper level course.

Fivefold Bonding in a Cr(I) Dimer Updated and Expanded

Submitted by T Brown / SUNY Oswego on Sat, 06/03/2017 - 10:46
Description

This paper describes the synthesis and characterization of a Cr(I) dimer with a very short Cr-Cr distance. Computational studies support fivefold bonding between the chromium atoms. This paper could be used to introduce metal-metal multiple bonds and discuss the molecular orbital interactions of homonuclear diatomics including d-orbitals. More generally, it is a nice example to stimulate the discussion of what constitutes a bond and the various interpretations of bond order.

Ligand based reductive elimination from a thorium compound

Submitted by Chip Nataro / Lafayette College on Tue, 05/23/2017 - 16:52
Description

This literature discussion is based on a paper describing the ligand-based reductive elimination of a diphosphine from a thorium compound (Organometallics, 2017, ASAP). The thorium compound contains two bidentate NHC ligands providing an opportunity to discuss the coordination of these ligands. The ligand-based reduction is very subtle and would be challenging for students to pick up without some guidance. The compound undergoing reductive elimination also presents an excellent introduction into magnetic nonequivalence and virtual coupling.

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