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Main-group elements as transition metals

Abstract

The last quarter of the twentieth century and the beginning decade of the twenty-first witnessed spectacular discoveries in the chemistry of the heavier main-group elements. The new compounds that were synthesized highlighted the fundamental differences between their electronic properties and those of the lighter elements to a degree that was not previously apparent. This has led to new structural and bonding insights as well as a gradually increasing realization that the chemistry of the heavier main-group elements more resembles that of transition-metal complexes than that of their lighter main-group congeners. The similarity is underlined by recent work, which has shown that many of the new compounds react with small molecules such as H2, NH3, C2H4 or CO under mild conditions and display potential for applications in catalysis.

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Figure 1: Bonding in group 14 analogues of ethylene and alkynes.
Figure 2: Similarity of H 2 interactions with main-group and transition-metal compounds.
Figure 3: The reactions of various main-group and transition-metal species with H2 or NH3.
Figure 4: Reversible reactions of main-group compounds with unsaturated molecules.
Figure 5: Catalytic cycle for the reduction of imines by phosphine-boranes.
Figure 6: Structures and reactions of main-group diradicaloids.

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Acknowledgements

I thank the US NSF and the US Department of Energy Office of Basic Energy Sciences for financial support.

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Power, P. Main-group elements as transition metals. Nature 463, 171–177 (2010). https://doi.org/10.1038/nature08634

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