@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} } @article {139, title = {Self-Assembled p-Carborane Analog of p-Mercaptobenzoic Acid on Au{111}}, journal = {Chemistry of Materials}, year = {2015}, month = {06/2015}, type = {Article}, abstract = {

Thep-carborane cluster analog of p-mercaptobenzoic acid, 1

}, keywords = {boron compounds, carborane, crystallography, scanning tunneling microscopy, self-assembly}, doi = {10.1021/acs.chemmater.5b02263}, url = {http://pubs.acs.org/doi/pdf/10.1021/acs.chemmater.5b02263}, author = {John C Thomas and Ishtvan Boldog and Harsharn S Auluck and Pablo J Bereciartua and Michal Dusek and Jan Machacek and Zdenek Bastl and Paul S Weiss and Tomas Base} } @proceedings {135, title = {Self-assembled monolayers of polyhedral dicarbadodecaborane dithiols: a computational assesment of high coverage patterns}, journal = {18th Interdisciplinary Surface Science Conference (ISSC-18)}, year = {2011}, publisher = {Institute of Physics, Organised by the IOP Thin Films and Surfaces Group}, address = {Warwick University, UK}, abstract = {

During the last decade, carborane thiols were introduced as building blocks for self-assembled monolayers on metal surfaces.[1, 2, 3] This work follows up the first calculations of dicarbadodecaborane dithiolate moieties on gold under sparse coverage.[4] Their results were used to place the polyhedral dithiolate moieties on a (111) gold surface as densely as possible, that is one moiety over six surface gold atoms, and compare computationally their various possible arrangements by DFT calculations of periodical systems using the Abinit program.[5] The
intermolecular interactions force the moieties to deviate from the bonding geometry found under sparse coverage, the two sulfur atoms are now positioned at almost equal height over the surface. The calculated stability of the monolayer formed by 9,12-dithiolate is again significantly higher than that of the layer build from 1,2-dithiolate moieties.

[1] T. Base, Z. Bastl, Z. Plzak, T. Grygar, J. Plesek, M. Carr, V. Malina, J. Subrt, J. Bohacek, E. Vecernikova, O. Kriz, Langmuir 21 (2005) 7776-7785.
[2] T. Base, Z. Bastl, V. Havr }, url = {http://www.iop.org/conferences}, author = {Jan Machacek} } @article {125, title = {Synthesis and catalytic activity of spaced ferrocene oxazolines}, journal = {Collection of Czechoslovak Chemical Communications}, volume = {68}, year = {2003}, chapter = {1206}, doi = {10.1135/cccc20031206}, url = {http://cccc.uochb.cas.cz/68/7/1206/}, author = {Petr Stepnicka and Tomas Base and Ivana Cisarova and Jiri Kubista and Stepan Vyskocil and Martin Sticha} }