We report the synthesis and in vitro antimalarial activity of several new 4-amino-and 4-alkoxy-7-chloroquinolines carrying a linear dibasic side chain. Many of these chloroquine analogues have submicromolar antimalarial activity versus HB3 (chloroquine sensitive) and Dd2 (chloroquine resistant strain of P. falciparum) and low resistance indices were obtained in most cases. Importantly, compounds 11-15 and 24 proved to be more potent against Dd2 than chloroquine. Branching of the side chain structure proved detrimental to the activity against the CQR strain.

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We have converted Eu­(OH)3 single crystal nanowires to Eu2O3 single crystal nanowires and studied the transformation using temperature and atmosphere controlled X-ray powder diffraction. The single crystal Eu2O3 nanowires were investigated as a starting material for the preparation of controlled morphology synthesis of the magnetic semiconductors EuO, EuS, and EuSe using gas phase reagents. In addition, we also explored the synthesis of EuOCl nanowires from Eu2O3 as an alternative route to EuO and EuS nanowires.

Europium chalcogenide alloys, EuS x Se1–x , have been synthesized both in the solid-state and as colloidal nanoparticles; the composition, structure, magnetism, and optical band gaps have been characterized. The goal was to observe the consequences of selenium concentration on the electronic structure as evidenced by the optical and magnetic properties and whether these properties are maintained in the nanomaterials. Both solid-state and nanoparticle alloys obey Vegard’s law with a systematic change in cell constant as confirmed by the powder X-ray diffraction. The bulk materials form homogeneous alloys that exhibit a linear change in both magnetic and optical properties as a function of composition. A synthetic method to prepare nanoalloys with a wide range of S:Se ratio has been developed. The nanoalloys are homogeneous, and EDS mapping of single nanoparticles indicates relatively uniform S and Se composition across the nanocrystals. The magnetic properties of the nanoparticles appear to parallel those in the solid-state. Although the composition is an effective tool to tune to the optical band gap in the solid-state alloys with a linear change in E g with composition, the nanoparticle optical band gaps appeared to be shifted, which we attribute to the presence of an amorphous selenium phase. The study of the properties of colloidal alloys highlights the importance of the mechanism of nanoparticle formation to control composition and purity.

Review: synthetic strategies and magnetic properties as function of size and compositin; 119 refs.