Covalent d-Block Organometallics: Teaching Lewis Structures and sd/sd[superscript 2] Hybridization Gives Students Additional Explanations and Powerful Predictive Tools

Autor/in	Fekl, Ulrich
Titel	Covalent d-Block Organometallics: Teaching Lewis Structures and sd/sd[superscript 2] Hybridization Gives Students Additional Explanations and Powerful Predictive Tools
Quelle	In: Journal of Chemical Education, 98 (2021) 10, S.3189-3206 (18 Seiten)Infoseite zur Zeitschrift PDF als Volltext Verfügbarkeit
Zusatzinformation	ORCID (Fekl, Ulrich)
Sprache	englisch
Dokumenttyp	gedruckt; online; Zeitschriftenaufsatz
ISSN	0021-9584
DOI	10.1021/acs.jchemed.1c00323
Schlagwörter	Metallurgy; Chemistry; College Science; Science Instruction; Visual Aids; Inorganic Chemistry; Undergraduate Students; Teaching Methods + Suchen Sie Ihr Suchwort? Hüttenwesen; Chemie; Teaching of science; Science education; Natural sciences Lessons; Naturwissenschaftlicher Unterricht; Anschauungsmaterial; Anorganische Chemie; Teaching method; Lehrmethode; Unterrichtsmethode
Abstract	Despite tremendous efforts by instructors and textbook authors, students find it difficult to develop useful chemical intuitions about structures and key properties of the important d-block organometallic species that have a d[superscript 6], d[superscript 8], or d[superscript 10] d-electron count. A full molecular orbital analysis is not always practical, and crystal field theory, while generally useful, is too limited here. It would be helpful to give students of organometallic chemistry an additional toolkit for understanding highly covalent d-block compounds. Hybridization arguments involving s and d orbitals (such as sd/sd[superscript 2] hybridization for d[superscript 8]/d[superscript 6] systems) provide useful insight, as is known from the research literature but rarely taught in undergraduate courses. This article makes descriptions of bonding that are based on s,d-hybridized orbitals more accessible, targeted toward undergraduate teaching. Geometries of unusual low-coordinate structures can be predicted. An in-depth physical explanation for the "trans" influence is provided. A clear explanation is given for the higher stability of the "cis" isomers versus the "trans" isomers in square-planar d[superscript 8] complexes MR[subscript 2]L[subscript 2] (R = alkyl/aryl, L = relatively weakly bonded neutral ligand) and for the "fac" versus "mer" isomers in octahedral d6 complexes MR[subscript 3]L[subscript 3]. Relevant to catalysis, it is explained why strongly donating ligands do not always facilitate oxidative addition and why 12-electron and 14-electron Pd(0) species are thermodynamically much more accessible than expected. The method capitalizes on first year knowledge, namely, the ability to write Lewis structures and to use hybridization arguments. It ties into the upper-year experience, including graduate school, where covalent d-block complexes may be encountered in research and where hybridization schemes will naturally emerge from using the natural bond orbital (NBO) formalism. It is discussed where the method might fit into the inorganic curriculum. (As Provided).
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Erfasst von	ERIC (Education Resources Information Center), Washington, DC
Update	2024/1/01