Main Group Cations, Radicals, Metal Complexes and Their Applications

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As part of the ongoing research within my research group, in this proposal we will be focusing on the following projects that span our areas of specialty including main group and transition metal synthetic chemistry:***1. Low-valent and/or low oxidation state heavy Group 13 elements: Cations and radicals stabilized by electron-rich ligands***In the area of Group 13 cations and radicals we aim to develop the appropriate molecular frameworks that are necessary to electronically and sterically stabilize these molecules. A complete understanding of these systems will provide insight to the bonding of Al with other atoms and at the same time, allow us to determine if these molecules can be used as ligands on transition metals. This work is expected to have a high impact in the area involving fundamental reactivity and bonding in these metals.***2. Chelating Cp/aryl based ligands for main group and transition metal complexes ***We aim to prepare a suite of mono anionic ligands similar to known constrained geometry-type of ligands where the metal center is chelated by one cyclopentadienyl (Cp) anionic ring and one, neutral aryl ring, both separated by o-positioning about a backbone aryl ring. Altering the substituents on the (Cp) ring and the aryl ring will tune the electronics and sterics of these molecules, allowing for the studying of the bonding. In the case of some metals, for example iron, the strained Cp-Aryl angle will cause a significant destabilization of the frontier molecular orbitals when compared to ferrocene, Cp2Fe, or [Cp-Fe-Benzene] cations, allowing for unprecedented reactivity to take place.***3. The chemistry of white phosphorus (P4) with hydrogen***Our experience in P4 chemistry has lead us to investigate the fundamental reactivity of P4 with both a proton and a hydrogen atom. To date, there is only evidence of the existence of [P4H]+ in the gas phase. Through judicious selection of a "super acid" and solvent choice we plan on identifying [P4H]+ in solution and isolating it in the solid state. In a similar vein, the reactivity of P4 with a hydrogen atom is proposed to be studied using muonium, a light isotope of hydrogen. ***4. Electron-rich organic and inorganic molecules***Recently we have had success in the preparation of electron rich, highly unsaturated "organic" molecules, many of them highly colored. These systems are stable derivatives of the highly reactive propargyl cation [H2C-CC-H]+ and its related radical. We aim to explore various substitution patterns about a central, highly unsaturated fragment [para-CC-C6H4-CC]. These "inorganic" analogues of our original molecules will be made by substituting the ends of the [para-CC-C6H4-CC] with phosphorus or boron-based molecules. We also propose making a "push-pull" type of system where an e- donating group is attached to one end and an e- withdrawing group is on the other. These substitutions will allow for the tuning of their properties and reactivity.**