Methyl esters were produced at several temperatures (10, 35, and 45 °C) by transesterification batch reactions
of soybean oil with methanol utilizing KOH and NaOH catalysts. The reactions were monitored by aliquot
removal and subsequent proton nuclear magnetic resonance spectroscopy (1H NMR) analysis. 1H NMR analysis
allowed for the calculation of the average degree of fatty acid unsaturation (DU = 1.52) in oil and methyl
ester. 1H NMR analysis also provided initial rates of methyl ester formation and an activation energy of 27.2
kJ/mol. The time-dependent concentration data revealed substantial reaction progress toward equilibrium after
only 120 s at a reduced temperature of 10 °C. Understanding the resonance shifts in the 1H NMR spectra of
starting materials and products allows for quantitation of reaction progress that is in good agreement with
results obtained using other analytical methods.
A major chemical challenge facing implementation of 225 Ac in targeted alpha therapyan emerging technology that has potential for treatment of diseaseis identifying an 225 Ac chelator that is compatible with in vivo applications. It is unclear how to tailor a chelator for Ac binding because Ac coordination chemistry is poorly defined. Most Ac chemistry is inferred from radiochemical experiments carried out on microscopic scales. Of the few Ac compounds that have been characterized spectroscopically, success has only been reported for simple inorganic ligands. Toward advancing understanding in Ac chelation chemistry, we have developed a method for characterizing Ac complexes that contain highly complex chelating agents using small quantities (μg) of 227 Ac. We successfully characterized the chelation of Ac 3+ by DOTP 8− using EXAFS, NMR, and DFT techniques. To develop confidence and credibility in the Ac results, comparisons with +3 cations (Am, Cm, and La) that could be handled on the mg scale were carried out. We discovered that all M 3+ cations (M = Ac, Am, Cm, La) were completely encapsulated within the binding pocket of the DOTP 8− macrocycle. The computational results highlighted the stability of the M(DOTP) 5− complexes.
In this Perspective, we provide a brief background on the use of aromatic phosphonic acid modifiers for tuning work functions of transparent conducting oxides, for example, zinc oxide (ZnO) and indium tin oxide (ITO). We then introduce our preliminary results in this area using conjugated phosphonic acid molecules, having a substantially larger range of dipole moments than their unconjugated analogues, leading to the tuning of ZnO and ITO electrodes over a 2 eV range as derived from Kelvin probe measurements. We have found that these work function changes are directly correlated to the magnitude and the direction of the computationally derived molecular dipole of the conjugated phosphonic acids, leading to the predictive power of computation to drive the synthesis of new and improved phosphonic acid ligands.
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