Trent H. Galow

Binary and Ternary Polymer‐Mediated “Bricks and Mortar” Self‐Assembly of Gold and Silica Nanoparticles

An amine-functionalized polymer has been used to simultaneously assemble carboxylic acid functionalized gold and silica nanoparticles into extended aggregates. This three component assembly process is highly versatile, with aggregate morphology controlled through stoichiometry, and nanoparticle segregation within the aggregate regulated through order of component addition.

Highly reactive heterogeneous Heck and hydrogenation catalysts constructed through ‘bottom-up’ nanoparticle self-assembly

Polymer-mediated self-assembly of functionalized Pd and SiO2 nanoparticles provides highly active hydrogenation and Heck coupling catalysts.

Fluorescence enhancement by symmetry breaking in a twisted triphenylene derivative.

1,4,5,8,9,12-hexamethyltriphenylene (HMTP) shows a high photoluminescence quantum yield (PLQY) of 31% in the solid state, making it of interest for luminescence applications. The detailed photophysical properties of HMTP have been investigated by using time-resolved and steady-state luminescence, PLQY, and molar absorption coefficient measurements. An enhancement of the transition dipole moment for fluorescence and absorption was demonstrated compared to the case of unsubstituted triphenylene, which resulted in a 20-fold increase in the radiative decay rate. This is attributed to a breaking of triphenylene symmetry as a result of the necessarily twisted structure induced by steric crowding. In addition, it was shown that HMTP shows similar photoluminescence energies in solution, powder, and film, indicating a reduced propensity for intermolecular π-stacking compared to the case of triphenylene, as a result of this twisted structure. This work also develops a method for calculating the photoluminescence quantum yield of powders by using a calibrated photodiode in combination with an uncalibrated CCD spectrometer.

Flavins as modular and amphiphilic probes of silica microenvironments

The amphiphilic and solvochromatic characteristics of flavins are utilized as a non-invasive polarity sensor for silica-based media.

Vicinal tricarbonyls as redox-controlled molecular rotors ☆

Abstract Using electrochemistry, spectroelectrochemistry and density functional computational methods, we have demonstrated that tricarbonyl amide 1 ox undergoes reversible conformational switching upon reduction to the corresponding radical anion 1 rad − .

Communication of electronic information over nanometer distances with supramolecular transduction. An experimental and density functional investigation

We have synthesized a family of conjugated diaminotriazine-functionalized receptors. Variation of distal functionality modulated the affinity of these receptors for flavin, demonstrating efficient electronic communication over a distance of 11 A. The origin of this communication was explored using DFT methodology. These calculations demonstrate that modulation of recognition in these systems is derived from a complex push–pull type mechanism.

Model systems for flavoenzyme activity: aromatic stacking in sol-gel matrices

Silicate matrices effectively replicate both the isolation and preorganization found in the active sites of flavoenzymes.

A ‘Building Block’ Approach To Mixed-Colloid Systems Through Electrostatic Self-Organization

We have developed a highly modular electrostatically-mediated approach to colloid-colloid and polymer-colloid networks using ‘building block’ and ‘bricks and mortar’ self-assembly methodologies, respectively. The former approach involved functionalization of one type of nanoparticle building block with a primary amine and a counterpart building block with a carboxylic acid derivative. After combining these two systems, acid-base chemistry followed by immediate charge-pairing resulted in the spontaneous formation of electrostatically-bound mixed-nanoparticle constructs. The shape and size of these ensembles were controlled via variation of particle size and stoichiometries. In the ‘bricks and mortar’ approach, a functionalized polymer is combined with complementary nanoparticles to provide mixed polymer-nanoparticle networked structures. A notable feature is the inherent porosity resulting from the electrostatic assembly. The shape and size of these ensembles were controlled via variation of particle size, stoichiometries and the order in which they were added.