Editor's Page pubs.acs.org/Organometallics
Literature-Based Teaching Strategies for Organometallic Courses task: how can the entire field of organometallic chemistry be condensed into 26 papers? The answer, simply, is that it did not have to be. The idea in this issue is to expose students to manuscripts that highlight the central, foundational concepts that define the field with the goal of inspiring their further independent learning endeavors in organometallic chemistry and beyond. And so, we arrived at the articles included in this issue. For the majority of the articles included here, LOs have already been developed and published on VIPEr. Several of these LOs were developed at NSF-funded faculty development workshops run by the IONiC VIPEr leadership. In general, LOs help students digest the papers by asking a series of probing questions. In many cases questions build from fundamental concepts (often not covered in the paper, e.g., electron counting) all the way to advanced material (e.g., the conclusions of the paper). These LOs are grouped together in a collection on VIPEr, available at https://www.ionicviper. org/collection/virtual-issue-organometallics. All of the LOs include learning goals, which are brief descriptions of what students are expected to learn from reading the paper and completing each LO. Tips for using the LOs in the classroom and feedback and assessment data are also provided. The seven papers in this issue that do not include LOs are the initial description of teaching organometallics through the literature from Duncan and Johnson,2 a paper on using the Covalent Bond Classification method for electron counting from Parkin and Green,3 a paper on charge distribution in organometallic compounds from Wolczanski,4 three excellent Tutorials from Labinger, Evans, and Schrock and Copéret,5−7 and a paper of a more historical slant from Kronauge and Mindiola, which examines the unique relevance of M−C bonds in nuclear medicine.8 These seven papers are designed to be more teaching/review in nature and as such do not fit well in the LO model but are excellent instructional resources. The remainder of the papers range from classic papers, covering topics of great importance to the field, to recently published articles that were chosen by members of the IONiC VIPEr community, who viewed the papers as being valuable for teaching purposes. Catalytic processes are a very important aspect of organometallic chemistry, and therefore we deemed it important to include a variety of catalytic systems in this issue. Most of the classic papers include some form of catalysis in order to provide a historical perspective into the development of this field. The oldest paper in this issue is the first ever scholarly journal report of the Monsanto Acetic Acid Process from Forster.9 This communication is perfect for introducing catalytic cycles, and the level of detail in the manuscript provides plenty of opportunities for students to think about the individual steps occurring in the process. Olefin metathesis is another important catalytic reaction in organometallic chemistry. While there are numerous available options, the paper by
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he Interactive Online Network of Inorganic Chemists (IONiC) was formed to build a community of educators in the field of inorganic chemistry.1 Two of our main products are the Virtual Interactive Pedagogical Educational Resource (VIPEr, www.ionicviper.org) and an annual summer faculty development workshop. Both products are designed to take faculty out of their comfort zones and encourage them to teach the breadth of the field in their classroom. A primary focus of the workshops and the web site, the killer app, if you will, is to bring cutting-edge primary literature into the undergraduate classroom. Over the past decade, the network has populated the VIPEr Web site with over 800 learning objects (LOs), which are discrete, small modules on a variety of topics ready for incorporation into an undergraduate classroom by a nonexpert. The primary focus has been literature discussion LOs, which serve to bridge the gap between textbook learning and primary literature consumption. Our workshops have trained 112 faculty members, graduate students, and postdocs interested in becoming faculty members in the use of VIPEr, active learning strategies, and incorporation of the primary literature into the classroom. Part of the driving force for the development of VIPEr stemmed from an idea two of us (A.R.J. and A.P.D.) had several years ago. We set out to design an undergraduate course in organometallic chemistry based on “classic” papers in the field, with the broad goal of transitioning advanced undergraduates away from textbook-based learning and toward using the primary literature as a source of information. In its first iteration (Spring 2005), the course was cotaught (by A.R.J. and A.P.D.) at Harvey Mudd College. In the years since, we have continued to teach the course individually, both at Harvey Mudd (A.R.J.) and at Pomona College and Willamette University (A.P.D.). Although the specific format of the course has varied from year to year, the general structure, as previously described, has remained largely intact.2 We conceived of three main components: first, an introductory series of lectures given by the faculty; second, student-led presentations of the designated classic papers; third, a written literature review describing an area of the field not otherwise covered in the course. Student feedbackboth formal and informalhas been highly positive in each iteration of the course. Students consistently report that expectations associated with capturing and internalizing information from the primary literature, as well as the planning and execution of full class-period presentations, are significantly elevated in comparison to prior courses they have taken. The students also affirm that the acquisition of research, presentation, and discussion skills are among their most significant takeaways. From an instructor standpoint, the structure of the course gives the flexibility to change content (by swapping out papers) and approach (by changing the nature of assignments) year to year. For this virtual issue, we have assembled a collection of papers that could be used to teach an entire course on organometallic chemistry. Of course this was quite a daunting © 2017 American Chemical Society
Published: August 14, 2017 2703
DOI: 10.1021/acs.organomet.7b00450 Organometallics 2017, 36, 2703−2705
Organometallics
Editor's Page
by Barrett and Iluc.25 While the compounds of both metals displayed similar reactivity, the palladium compounds were inherently less stable and thus decomposed more in various reactions. The polymerization of rac-lactide was accomplished by Byers and co-workers using a series of bis(imino)pyridine alkoxide iron catalysts.26 The catalytic activity was found to depend on the nature of the alkoxide ligand and the valence of the iron; with iron(II) the polymerization was living, but upon oxidation to iron(III) the polymerization terminated. The valence of the metal also plays an important role in a recent study of the reductive elimination of diphosphine from a thorium(IV) compound, which Arnold and Garner found occurred via a ligand-based reduction of bipyridine as opposed to a classical metal-based reduction.27 It is our hope that the papers in this issue, paired with the available LOs, will provide a powerful introduction to key work in the field of organometallic chemistry and will motivate students and teachers alike to keep reading, push the limits of their knowledge, and apply what they have learned to new ideas. Perhaps this approach will even energize them to learn more about organometallic chemistry.
Grubbs et al. presents a kinetic and mechanistic study of this process in addition to examining the impact of varying the ligands on the catalyst efficiency.10 The effect of varying ligands, in particular phosphine and cyclopentadienyl ligands, on the heat of protonation of iridium compounds is presented in a paper by Wang and Angelici.11 In this study the reaction of Cp′Ir(CO)(PR3) with HOTf was found to be more favorable with more electron donating ligands, consistent with the observed trend in νCO data for the complexes in question. The effect of changing ligands was also examined in C−H bond activation of arenes by Jones and Feher.12 Insights into the mechanism of the activation were found by using C6H6 and C6D6 in the reactions. A second mechanistic paper from Breitung et al. examined carbon−carbon and carbon−iodine reductive eliminations from a platinum(IV) compound.13 The final classic papers present the coordination of two diatomic elements, H214 (Wasserman and coauthors) and N2,15 (Chirik et al.) to transition-metal centers. The more recent papers in this issue are all from the past decade, with the majority appearing in the last four years. On the basis of a combination of kinetic data and computational studies, Ison and co-workers posited an unusual direct insertion of CO into the rhenium−carbon bonds of several oxorhenium(V) complexes.16 Following up on previous studies demonstrating that Ir(III) bis(acetate) complexes stoichiometrically dehydrogenate n-octane, Goldberg and co-workers demonstrated that Ir(III) hydride complexes generated as byproducts of the dehydrogenation can be converted back to starting Ir(III) bis(acetate) complexes by molecular oxygen.17 Although this system is not itself catalytic, it suggests that a catalytic variant using O2 as a terminal oxidant may be possible. Dias and Wu performed a systematic, detailed structural study of coinage-metal ethylene complexes supported by fluorinated tris(pyrazolyl)borate ligands, establishing that all three complexes in the isoleptic Cu/Ag/Au series featured unusual κ2 coordination of the tris(pyrazolyl) ligand to the metal center.18 Legzdins and coauthors provide a report of a tungsten complex capable of functionalizing methane into unsymmetrical unsaturated ketones.19 The electrochemistry of a family of half-sandwich ruthenium hydride complexes with bidentate metallocene-based phosphine ligands is described in a paper by Nataro, Norton, and colleagues; protonation of the complexes led to the transdihydride in all cases but one, which formed a molecular dihydrogen complex.20 A large family of pincer ligand complexes was prepared by Kirchner and co-workers from zerovalent group VI metal carbonyls using a solvothermal technique. The carbonyl stretching frequencies were used to characterize the steric and electronic parameters of the pincer ligands.21 Returning to catalysis, ruthenium half-sandwich complexes, this time with N-heterocyclic carbene supporting ligands, were used for transfer hydrogenation of a variety of substrates in a study by Nikonov and Mai.22 Another paper by Norton and colleagues explores early-metal insertion chemistry with the reaction of isonitriles with a zirconium butadiene complex to form η2-iminoacyl complexes; activation of CO is also reported.23 Ritter and coauthors report the occurrence of nucleophilic attack at an arene coordinated to iridium, and this reaction, while not catalytic, leads to a synthetic cycle for the hydroxylation of benzene.24 The synthesis and reactivity of trigonal-planar palladium and platinum carbene compounds without heteroatom substituents on the carbenes was examined
Andrew P. Duncan† Adam R. Johnson‡ Chip Nataro*,§
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† Department of Chemistry, Willamette University, Salem, Oregon 97301, United States ‡ Department of Chemistry, Harvey Mudd College, Claremont, California 91711, United States § Department of Chemistry, Lafayette College, Easton, Pennsylvania 18042, United States
AUTHOR INFORMATION
Corresponding Author
*E-mail for C.N.:
[email protected]. Notes
Views expressed in this editorial are those of the authors and not necessarily the views of the ACS.
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REFERENCES
(1) Jamieson, E. R.; Eppley, H. J.; Geselbracht, M. J.; Johnson, A. R.; Reisner, B. A.; Smith, S. R.; Stewart, J. L.; Watson, L. A.; Williams, B. S. Inorg. Chem. 2011, 50, 5849. (2) Duncan, A. P.; Johnson, A. R. J. Chem. Educ. 2007, 84, 443. (3) Green, M. L. H.; Parkin, G. J. Chem. Educ. 2014, 91, 807. (4) Wolczanski, P. T. Organometallics 2017, 36, 622. (5) Labinger, J. A. Organometallics 2015, 34, 4784. (6) Evans, W. J. Organometallics 2016, 35, 3088. (7) Schrock, R. R.; Copéret, C. Organometallics 2017, 36, 1884− 1892. (8) Kronauge, J. F.; Mindiola, D. J. Organometallics 2016, 35, 3432. (9) Forster, D. J. Am. Chem. Soc. 1976, 98, 846. (10) Sanford, M. S.; Love, J. A.; Grubbs, R. H. J. Am. Chem. Soc. 2001, 123, 6543. (11) Wang, D.; Angelici, R. J. Inorg. Chem. 1996, 35, 1321. (12) Jones, W. D.; Feher, F. J. J. Am. Chem. Soc. 1986, 108, 4814. (13) Goldberg, K. I.; Yang, J.; Breitung, E. M. J. Am. Chem. Soc. 1995, 117, 6889. (14) Kubas, G. J.; Ryan, R. R.; Swanson, B. I.; Vergamini, P. J.; Wasserman, H. J. J. Am. Chem. Soc. 1984, 106, 451. (15) Hanna, T. E.; Lobkovsky, E.; Chirik, P. J. J. Am. Chem. Soc. 2004, 126, 14688. (16) Robbins, L. K.; Lilly, C. P.; Smeltz, J. L.; Boyle, P. D.; Ison, E. A. Organometallics 2015, 34, 3152.
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(17) Allen, K. E.; Heinekey, D. M.; Goldman, A. S.; Goldberg, K. I. Organometallics 2014, 33, 1337. (18) Dias, H. V. R.; Wu, J. Organometallics 2012, 31, 1511. (19) Baillie, R. A.; Patrick, B. O.; Legzdins, P.; Rosenfeld, D. C. Organometallics 2017, 36, 26. (20) Shaw, A. P.; Norton, J. R.; Buccella, D.; Sites, L. A.; Kleinbach, S. S.; Jarem, D. A.; Bocage, K. M.; Nataro, C. Organometallics 2009, 28, 3804. (21) Mastalir, M.; de Aguiar, S. R. M. M.; Glatz, M.; Stöger, B.; Kirchner, K. Organometallics 2016, 35, 229. (22) Transfer hydrogenation: Mai, V. H.; Nikonov, G. I. Organometallics 2016, 35, 943. (23) Valadez, T. N.; Norton, J. R.; Neary, M. C.; Quinlivan, P. J. Organometallics 2016, 35, 3163. (24) D’Amato, E. M.; Neumann, C. N.; Ritter, T. Organometallics 2015, 34, 4626. (25) Barrett, B. J.; Iluc, V. M. Organometallics 2017, 36, 730. (26) Biernesser, A. B.; Li, B.; Byers, J. A. J. Am. Chem. Soc. 2013, 135, 16553. (27) Garner, M. E.; Arnold, J. Organometallics 2017, DOI: 10.1021/ acs.organomet.7b00301.
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