Density functional theory and ab initio methods have been used to calculate the structures and energies of minima and transition states for the reactions of methane coordinated to a transition metal. The reactions studied are reversible C-H bond activation of the coordinated methane ligand to form a transition metal methyl hydride complex and dissociation of the coordinated methane ligand. The reaction sequence can be summarized as L(x)M(CH(3))H <==> L(x)M(CH(4)) <==> L(x)M + CH(4), where L(x)M is the osmium-containing fragment (C(5)H(5))Os(R(2)PCH(2)PR(2))(+) and R is H or CH(3). Three-center metal-carbon-hydrogen interactions play an important role in this system. Both basis sets and functionals have been benchmarked in this work, including new correlation consistent basis sets for a third transition series element, osmium. Double zeta quality correlation consistent basis sets yield energies close to those from calculations with quadruple-zeta basis sets, with variations that are smaller than the differences between functionals. The energies of important species on the potential energy surface, calculated by using 10 DFT functionals, are compared both to experimental values and to CCSD(T) single point calculations. Kohn-Sham natural bond orbital descriptions are used to understand the differences between functionals. Older functionals favor electrostatic interactions over weak donor-acceptor interactions and, therefore, are not particularly well suited for describing systems--such as sigma-complexes--in which the latter are dominant. Newer kinetic and dispersion-corrected functionals such as MPW1K and M05-2X provide significantly better descriptions of the bonding interactions, as judged by their ability to predict energies closer to CCSD(T) values. Kohn-Sham and natural bond orbitals are used to differentiate between bonding descriptions. Our evaluations of these basis sets and DFT functionals lead us to recommend the use of dispersion corrected functionals in conjunction with double-zeta or larger basis sets with polarization functions for calculations involving weak interactions, such as those found in sigma-complexes with transition metals.

A thematic course called "Climate Change: Chemistry and Controversy" was developed for upper-level non-STEM students. This course used the socioscientific context of climate change to teach chemical principles and the nature of science. Students used principles of agnotology (direct study of misinformation) to debunk climate change misconceptions commonly encountered in the media and politics. The culmination of the course was a service-learning project to create training documents for staff at a local science center that explained common climate misconceptions. In the process of completing this project, students gained a greater appreciation for the nature of science and learned chemical principles of electromagnetic radiation, atomic structure (isotopes), molecular structure (Lewis structures, VESPR, and polarity) spectroscopy, and stoichiometry. This paper summarizes the outcomes of the course, teaching strategies used to reach the outcomes, and strategies for incorporating agnotology and socioscientific study in science courses.

Structured collaborative peer teams are widely recognized as a high-impact pedagogy that supports learning outcomes for diverse learners but it can be difficult to implement this pedagogy in an online environment. This communication describes a structure to use collaborative teams to develop and sustain a community of inquiry in an asynchronous online environment. Courses were designed to support the individual learner by developing strong peer-to-peer learning in teams. We describe how asynchronous teams were structured and what specific activities (cognitive and instructor-based) helped teams work effectively through the term. This practice was applied in two different environments: a first-year course at a two-year community college and a first-year lab sequence at a four-year university. At both institutions, student reflections described how teams supported learning and allowed development of process skills. Our results suggest that structured teams can support student learning in asynchronous classes at a wide range of institutions.

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