Isomerism in Coordination Complexes

Submitted by Anthony L. Fernandez / Merrimack College on Thu, 01/18/2018 - 12:07
Description

Students are confronted with a number of new types of isomerism as they move from organic chemistry into inorganic chemistry. This can be confusing and students often have trouble visualizing structures and differentiating between isomers. In this exercise, students are asked to examine a number of different crystal structures from the Teaching Subset (distributed with Mercury version 3.10, early 2018) of the Cambridge Structural Database.

Geometry Indices

Submitted by Anthony L. Fernandez / Merrimack College on Fri, 01/12/2018 - 23:20
Description

In the primary literature, goemetry indices are being used quite often to describe four- and five-coordinate structures adopted by transition metal complexes. This slide deck, which is longer than the intended 5 slides, describes the three common geometry indices (tau4, tau4', and tau5) and provides example calculations for structures that are freely available in the Teaching Subset of the Cambridge Structural Database. (Students can access these structures in Mercury, which is freely available from the CCDC, or via a web request form for which the link is provided below.)

Inclusive Pedagogy: A Misidentified Molecule and Paper Retraction

Submitted by Sibrina Collins / Lawrence Technological University on Sun, 09/10/2017 - 19:20
Description

This learning object focuses on teaching students how to read and use Chemical and Engineering News for class discussions and critically evaluate the scientific literature. Recently, Chemical and Engineering News published an article about the retraction of a 15-year old paper, which had misidentified a multidentate ligand, which is central to the paper (Ritter, S.K. “Chemist Retract 15-year old paper and publish a revised version.” Chem. Eng. News, 2017, 95, (36), p6).

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. 2007104(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.

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.