Energetics of Hypervalent Bonds

Northern Illinois University, Dekalb IL

Investigators

Abstract

Lee Sunderlin of Northern Illinois University is supported by a grant from the Experimental Physical Chemistry Program to measure the dissociation energies of polyhalides and other systems involving hypervalent three-center four-electron bonds. Information is only available for these types of species from condensed phase studies where solvent effects are involved. For this, he will use threshold collision-induced dissociation in a flowing afterglow tandem mass spectrometer apparatus. The specific systems that will be investigated are mixed linear polyhalide anions, as well as branched hypervalent halides of germanium, phosphorus sulfur and iodine, and isoelectronic compounds. Other species, including [(CH3)2Sb]3- and POF4-, will be studied as time permits to determine how non-halide terminal groups effect the bonding and to provide an anchor for fluoride affinities that are presently available. These studies will lead to a further understanding of hypervalent chemical bonding, in particular that involving three-centered bonds containing four electrons. The studies are complimentary to those in solution, where there are extensive solvent effects, and will provide a wealth of data on bond strengths. The information is important in fields as diverse as organic superconductors, iodine-starch tests, mass spectrometry and atmospheric chemistry.