A Bonding Quandary—or—A Demonstration of the Fact That Scientists Are Not Born With Logic


  • Santiago Alvarez Prof.,

    1. Departament de Química Inorgànica and Institut de Química Teòrica i Computacional (IQTC-UB), Universitat de Barcelona, Martí i Franquès 1-11, 08028 Barcelona (Spain), Fax: (+34) 93-4907725
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  • Roald Hoffmann Prof.,

    1. Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY 14853-1301 (USA), Fax: (+1) 6072555707
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  • Carlo Mealli Dr.

    1. Istituto di Chimica dei Composti Organometallici, ICCOM-CNR, Via Madonna del Piano 10, 50019 Sesto Fiorentino, Firenze (Italy), Fax: (+39) 055225203
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We document here a spirited debate among three colleagues and friends who have strong opinions on a specific bonding problem, the presence or absence of a cross-ring sulfur–sulfur bond in a trinuclear Cu3S2 cluster. The example may seem esoteric, but through their struggles with this specific bond (and with each other) the authors approach the more general problematic of chemistry, the chemical bond. The discussion focuses on bond lengths and the population of bonding and antibonding orbitals, and on oxidation states, electron counting, and associated geometries. It expands to encompass other bonding criteria, and introduces examples ranging far across organic and inorganic chemistry. The authors suggest molecules that might test their ideas. An Appendix to the paper discusses a matter rarely broached in the chemical literature—should one review for publication a paper which criticizes one of your own contributions.