@article {152, title = {Formation of Highly Ordered Terminal Alkyne Self-Assembled Monolayers on the Au{111} Surface through Substitution of 1-Decaboranethiolate}, journal = {J. Phys. Chem. C}, volume = {123}, year = {2019}, pages = {1348{\textendash}1353}, abstract = {

The reaction aimed at completing and closing the open cages of 1-decaboranethiol self-assembled monolayers (SAMs) on Au{111} with 4-phenyl-1-butyne results in highly ordered monolayers of 4-phenyl-1-butyne. The initially disordered 1-decaboranethiolate changed into ordered (√3{\texttimes}√3)R 30{\textdegree} lattices on Au{111} typical of alkyne SAMs, indicating the complete substitution of 1-decaboranethiolate moieties, as determined by nanoscale imaging with scanning tunneling microscopy and X-ray photoelectron spectroscopy. Vibrational spectroscopy results indicate that the process happens gradually and that alkynyl groups are not totally oxidized in the ordered 4-phenyl-1-butyne monolayer.

}, keywords = {alkyne, decaborane, gold, self-assembly, surface, thiol}, doi = {10.1021/acs.jpcc.8b11033}, url = {https://pubs.acs.org/doi/10.1021/acs.jpcc.8b11033}, author = {Shenkai Wang and Dominic P Goronzy and Thomas D Young and Natcha Wattanatorn and Logan Stewart and Tomas Base and Paul S Weiss} } @article {143, title = {Surface Dipole Control of Liquid Crystal Alignment}, journal = {JACS}, volume = {138}, year = {2016}, month = {April 19, 2016}, pages = {5957-5967}, chapter = {5957}, abstract = {

Detailed understanding and control of the intermolecular forces that govern molecular assembly are necessary to engineer structure and function at the nanoscale. Liquid crystal (LC) assembly is exceptionally sensitive to surface properties, capable of transducing nanoscale intermolecular interactions into a macroscopic optical readout. Self-assembled monolayers (SAMs) modify surface interactions and are known to influence LC alignment. Here, we exploit the different dipole magnitudes and orientations of carboranethiol and dithiol positional isomers to deconvolve the influence of SAM-LC dipolar coupling from variations in molecular geometry, tilt, and order. Director orientations and anchoring energies are measured for LC cells employing various carboranethiol and dithiol isomer alignment layers. The normal component of the molecular dipole in the SAM, toward or away from the underlying substrate, was found to determine the in-plane LC director orientation relative to the anisotropy axis of the surface. By using LC alignment as a probe of interaction strength, we elucidate the role of dipolar coupling of molecular monolayers to their environment in determining molecular orientations. We apply this understanding to advance the engineering of molecular interactions at the nanoscale.

}, keywords = {carborane, Dipole, liquid crystal, surface}, doi = {10.1021/jacs.6b02026}, url = {http://pubs.acs.org/doi/abs/10.1021/jacs.6b02026}, author = {Jeffrey J Schwartz and Alexandra M. Mendoza and Natcha Wattanatorn and Yuxi Zhao and Vinh T Nguyen and Alexander M Spokoyny and Chad A Mirkin and Tomas Base and Paul S Weiss} }