Heavy Heteroelement Multiple Bonds of Groups 13/14 and 13/15

Homo- and hetero- multiple bonding between second row elements, especially between carbon, nitrogen and oxygen, has been known for a long time. However, it was only recently that a relatively complete array of homo- atomic analogues of the heavier elements of group 13, 14 and 15 have been isolated and characterized. Many of these syntheses were made in the research group of Prof. P. P. Power. This has led to a sea change in the chemistry of multiply bonded compounds and in chemistry in general, for such compounds had been presumed to be unstable for a long time. These compounds were found to exhibit large differences in structure and reactivity from their well known multiply bonded analogues of the lighter second row elements. Yet, despite the considerable progress made with homo-atomic derivatives, the synthesis of compounds with multiple bonds between heavier elements of two different groups in the periodic system still remains a challenge for synthetic organometallic chemists. Having in mind the current application of group 13, 14 and 15 elements as semiconductors and various other industrial applications, the synthesis of compounds containing multiple bonds between the different elements is of considerable importance. The main objective of the proposed work is the synthesis and characterization of hitherto unknown molecules which feature hetero-atomic double bonds between elements of groups 13 and 14 and triple bonds between elements of groups 13 and 15 with principal number higher than two, i.e. between elements such as Al, Ga, In, Tl; Si, Ge, Sn, Pb and P, As, Sb and Bi. For this purpose, several novel synthetic strategies are outlined in this proposal. These include syntheses of unprecedented compounds with multiple bonds between heavier group 13/14 elements, as well as between heavier group 13/15 elements. Structural properties of the synthesized compounds will be characterized by means of X-ray, vibrational and UV-VIS spectroscopy, multinuclear NMR (also solid state NMR) spectroscopy. In addition, the investigation of the reactivity of the novel compounds will be carried out with emphasis on addition reactions of the non-symmetrical molecules. Also one electron oxidation and reduction reactions leading to radical ions will be studied by means of EPR spectroscopy and cyclic voltammetry, allowing insight in the electronic properties of heteroatomic multiple bonds between heavier main group elements. This work shall be carried out in the research group of Prof. Philip P. Power at the University of California at Davis.