Dispersion interactions, while weaker than most chemical bonds, can be very important in the self-assembly of nanostructures such as those based on carbon nanotubes or pi-conjugated sheets (graphenes). This talk will introduce the simplest ways of understanding these forces, then reveal a class of systems (zero-gap anistropic nanostructures including graphene and metallic nanotubes) where this simplest approach would appear to break down.

The recent discovery of stable 14 electron ruthenium phosphonium alkylidenes related to the Grubbs olefin metathesis catalyst portfolio has allowed us to probe the properties of the intermediates in the catalytic cycle for this important reaction. The synthesis and properties of these phosphonium alkylidenes will be discussed, and their conversion into ruthenacyclobutanes via reaction with olefins will be presented. Detailed NMR spectroscopic studies reveal the structural and dynamic properties of these previously unobservable intermediates.

Trianionic pincer ligands: nitrile synthesis via N-atom transfer, high oxidation state Cr(IV) and Cr(V) and new chemistry with W-W triple bonds Dr. Adam S. Veige University of Florida Abstract: Classic pincer ligands (A, E = P, N, O, S) are complementary to late transition. Our approach is to match the harder early transition metals with a harder pincer ligand. We have synthesized a series of new pincer ligands based on amidoarylideamido (B, Ar = 2,6iPrC6H3, and 3,5MeC6H3) and alkoxidearylidealkoxide linkages (C, OCO3 = 1,3-C6H4(6-tBuC6H3OH)2). Ligand Attributes 1.