Alkyl, silyl, and phosphane ligands are amongst the most familiar and ubiquitous ligands in organometallic and coordination chemistry. The C, Si, and P donor atoms of these ligands are sp3‐hybridized and the ligands are related to each other by the isolobal analogy: (CR3)−(SiR3)−PR3. Herein, we demonstrate that although a number of unusual observations concerning the reactivity and bonding of these ligands appears unrelated at first sight, they in fact provide offer an exiting and consistent picture that may form the basis for new paradigms. The characterization of stable complexes in which alkyl, silyl, and phosphane ligands behave as symmetrical bridges confirms that there is no inherent thermodynamic instability associated with these bonding situations, and, in fact, reactivity studies suggest that these ligands should be able to bridge between metal centers in reaction intermediates or transition states.

Boag, N.M.; Nelson, K.; Montag, B.; Brand, Jennifer I.; and Dowben, Peter A., "The electronic structure of 1,2-PCB 10 H 11 molecular films: a precursor to a novel semiconductor" (2006 Abstract: The band gaps and electronic structure of un doped fi lms of molecular icosahedra of closo-1-phospha-2 carbadodecaborane (1,2-PCB 10 H 11 ) are reported.

We have measured the molecular orientation and bonding of adsorbed ferrocene on Ag(100) and Cu(100) using angle-resolved photoemission spectroscopy (ARPES). The results for molecular adsorption on Ag(100) are complemented by high-resolution electron energy loss spectroscopy (HREELS) measurments and ab initio calculations for the ferrocene vibrational modes. The measurements indicate that ferrocene adsorbs on Ag(100) with the molecular axis perpendicular to the surface. In contrast, as indicated using ARPES and scanning tunneling microscopy, ferrocene adsorbed on the Cu(100) surface is oriented with the molecular axis parallel with the surface. Model calculations allow us to assign all of the observed vibrational modes for the weakly bound molecular ferrocene on Ag(100)-both dipole and impact scattering modes have been observed.

We compare the molecular films of three different isomers of closo-dicarbadodecaborane (orthocarborane (1,2-C2B10H12), metacarborane (1,7-C2B10H12), paracarborane (1,12-C2B10H12)) and two related icosahedral cage molecules, 1-phospha-2-carbadodecaborane (1,2-PCB10H11) and 1-phospha-7-carbadodecaborane (1,7-PCB10H11) adsorbed on a variety of substrates. While the experimental electronic structure from combined photoemission and inverse photoemission studies of the molecular films are in good agreement with semiempirical calculations for the isolated molecule, there is a shift in the chemical potential for each molecule. The experimental position of the molecular chemical potential implicates an influence of both interface and adsorbate dipole.