title: From group 13-group 13 donor-acceptor bonds to triple-decker cations.
abstract: Donor-acceptor bonding between group 13 elements seems counter-intuitive because one normally thinks of e.g. boron and aluminium compounds as classical Lewis acids. Indeed, many such compounds have achieved industrial prominence in this regard. Recently, however, it has become possible to stabilize these and other group 13 elements in the +1 oxidation state as opposed to the archetypical +3 oxidation state. Moreover, it turns out that in the +1 oxidation state these species are excellent donors--hence the formation of these unprecedented donor-acceptor bonds. The discovery of such bonds has led, albeit indirectly, to the development of triple-decker main group cations. This aspect is also covered in the review.
authors.affiliation: Department of Chemistry and Biochemistry, The University of Texas at Austin, 1 University Station A5300, Austin, Texas 78712, USA. cowley@mail.utexas.edu
authors.forename: Alan H
authors.initials: AH
authors.lastname: Cowley
mesh_terms: D000535:Aluminum / Q000737:chemistry; D001895:Boron / Q000737:chemistry; D002412:Cations / Q000737:chemistry; D018360:Crystallography, X-Ray; D005708:Gallium / Q000737:chemistry; D007204:Indium / Q000737:chemistry; D008670:Metals / Q000737:chemistry*; D008958:Models, Molecular; D015394:Molecular Structure; D009942:Organometallic Compounds / Q000737:chemistry; D010084:Oxidation-Reduction
chemical_list: D002412:Cations; D008670:Metals; D009942:Organometallic Compounds; D007204:Indium; D005708:Gallium; D000535:Aluminum; D001895:Boron