When size matters: exploring the potential of aminocyclopropenium cations as head groups in triphenylene-derived ionic liquid crystals in comparison with guanidinium and ammonium units

The influence of the size of a single ionic head group on the mesomorphic properties of hexaalkoxytriphenylenes was investigated by synthesising three derivatives with increasing head group diameter. The derivatives were investigated with optical polarising microscopy (POM), differential scanning calorimetry (DSC) and X-ray scattering (WAXS, SAXS). For the derivative with the small trimethylammonium head group, an enantiotropic mesophase was found. The derivative with the bigger tetramethylguanidine head group only showed a monotropic phase and the derivative with the largest bisdiisopropylaminocyclopropenium head group displayed no liquid crystaline properties at all.     

Kinetic Isotope Effect as a Tool To Investigate the Oxygen Reduction Reaction on Pt-based Electrocatalysts – Part I: High-loading Pt/C and Pt Extended Surface

Kinetic isotope effect (KIE) was used to study the rate-determining step for oxygen reduction reaction (ORR) on dispersed Pt/C electrocatalyst and polycrystalline Pt (Pt-poly). KIE is defined as the ratio of the kinetic current measured in protonated electrolyte versus deuterated electrolyte, with KIE values larger than one indicating proton participation in the rate-determining step. The effect of poisoning anions on the platinum rate determining step is investigated by assessing the KIE in perchloric (non-poisoning) and sulfuric acid-based electrolytes. The kinetics currents were calculated using the Koutechy-Levich and Tafel analysis. A KIE of 1 was observed for Pt/C (with a 40 wt.% Pt loading) and Pt-poly, thus indicating that, on 40 wt. % Pt/C and Pt-poly, the rate determining step is proton independent.     

Exploration of continuous-flow benchtop NMR acquisition parameters and considerations for reaction monitoring

This study focused on fundamental data acquisition parameter selection for a benchtop nuclear magnetic resonance (NMR) system with continuous flow, applicable for reaction monitoring. The effect of flow rate on the mixing behaviors within a flow cell was observed, along with an exponential decay relationship between flow rate and the apparent spin–lattice relaxation time (T1*) of benzaldehyde. We also monitored sensitivity (as determined by signal-to-noise ratios; SNRs) under various flow rates, analyte concentrations, and temperatures of the analyte flask. Results suggest that a maximum SNR can be achieved with low to medium flow rates and higher analyte concentrations. This was consistent with data collected with parameters that promote either slow or fast data acquisition. We further consider the effect of these conditions on the analyte's residence time, T1*, and magnetic field inhomogeneity that is a product of continuous flow. Altogether, our results demonstrate how fundamental acquisition parameters can be manipulated to achieve optimal data acquisition in continuous-flow NMR systems.     

Hybrid nanocapsules: interactions of ABA block copolymers with liposomes

Amphiphilic ABA triblock copolymers, such as poly(2-methyloxazoline)-block-poly(dimethylsiloxan)-block-poly(2-methyloxazoline) (PMOXA-PDMS-PMOXA), form vesicular structures. Here, the interaction of these ABA molecules with lipids is investigated by electron microscopy, fluorescence spectroscopy, light scattering, and differential scanning calorimetry. Our observations suggest the formation of homogeneous mixed polymer-lipid composites, independent of preparation method, i.e. film hydration, dispersion, or detergent removal. When ABA polymersomes and liposomes are mixed, we observed monomer exchanges on a time scale of minutes. The possibility of forming mixed structures and the exchanges between preformed structures allow the combination of the properties of lipids and polymers such as stability and loading encapsulation capacity.     

Combining player statistics to predict outcomes of tennis matches

^** Email: tbarnett{at}swin.edu.au^*** Email: sclarke{at}swin.edu.au With the growth in sports betting, it is possible to bet, bothbefore and during a match, on a range of outcomes in tennis.This paper shows how the standard statistics published by theATP can be combined to predict the serving statistics to beobtained when two given players meet. These statistics are thenused in a spreadsheet model to predict further match outcomes,such as the length of the match and chance of either playerwinning. These calculations can be updated as the match progresses.The method is demonstrated by focusing on a very long men'ssingles match between Roddick and El Aynaoui played at the 2003Australian Open.     

Digital holographic microscopy: a noninvasive contrast imaging technique allowing quantitative visualization of living cells with subwavelength axial accuracy

We have developed a digital holographic microscope (DHM), in a transmission mode, especially dedicated to the quantitative visualization of phase objects such as living cells. The method is based on an original numerical algorithm presented in detail elsewhere [Cuche et al., Appl. Opt. 38, 6994 (1999)]. DHM images of living cells in culture are shown for what is to our knowledge the first time. They represent the distribution of the optical path length over the cell, which has been measured with subwavelength accuracy. These DHM images are compared with those obtained by use of the widely used phase contrast and Nomarski differential interference contrast techniques.     

Gambling your way to New York: A story of expectation

Scenarios 1 and 2 assume the player only plays the one game to turn over the required 10,000. If a player had a good run in the first10,000. If a player had a good run in the first 5,000 turnover in Casino War, he or she may be inclined to switch to 3 Card Stud Poker. Likewise, if a player had a bad run in the first $5,000 turnover in 3 Card Stud Poker, he or she may be inclined to switch to Casino War. A player’s choice to switch between 3 Card Stud Poker and Casino War is dependent on his or her current bankroll and how many hands are left to play to wager the required $5,000 turnover in 3 Card Stud Poker, he or she may be inclined to switch to Casino War. A player’s choice to switch between 3 Card Stud Poker and Casino War is dependent on his or her current bankroll and how many hands are left to play to wager the required 10,000. The minimum bet for both games has always been applied. A player may choose to speed up the process by betting higher than the minimum. This may again depend on the player’s current bankroll and how many hands are left to play. In general, increasing the size of the bankroll in any casino game increases the variance and skewness. This would amount to increasing the probability of losing the initial 200 before wagering the initial200 before wagering the initial 5,000 (i.e., a greater chance of having to deposit more money into the casino account).     

In Situ Coupling of Single Molecules Driven by Gold‐Catalyzed Electrooxidation

A single‐molecule method has been developed based on the scanning tunneling microscope (STM) to selectively couple a series of aniline derivatives and create azobenzenes. The Au‐catalyzed oxidative coupling is driven by the local electrochemical potential at the nanostructured Au STM tip. The products are detected in situ by measuring the conductance and molecular junction elongation and compared with analogous measurements of the expected azobenzene derivatives prepared ex situ. This single‐molecule approach is robust, and it can quickly and reproducibly create reactions for a variety of anilines. We further demonstrate the selective synthesis of geometric isomers and the assembly of complex molecular architectures by sequential coupling of complementary anilines, demonstrating unprecedented control over bond formation at the nanoscale.     

Self-Assembly of Aminocyclopropenium Salts: En Route to Deltic Ionic Liquid Crystals

Aminocyclopropenium ions have raised much attention as organocatalysts and redox active polymers. However, the self-assembly of amphiphilic aminocyclopropenium ions remains challenging. The first deltic ionic liquid crystals based on aminocyclopropenium ions have been developed. Differential scanning calorimetry, polarizing optical microscopy and X-ray diffraction provided insight into the unique self-assembly and nanosegregation of these liquid crystals. While the combination of small headgroups with linear p-alkoxyphenyl units led to bilayer-type smectic mesophases, wedge-shaped units resulted in columnar mesophases. Upon increasing the size and polyphilicity of the aminocyclopropenium headgroup, a lamellar phase was formed.