Neutral impact ion scattering spectroscopy (NICISS) is used to measure the depth profiles of ionic surfactants, counterions, and solvent molecules on the angstrom scale. The chosen surfactants are 0.010 m tetrahexylammonium bromide (THA+/Br–) and 0.0050 m sodium dodecyl sulfate (Na+/DS–) in the absence and presence of 0.30 m NaBr in liquid glycerol. NICISS determines the depth profiles of the elements C, O, Na, S, and Br through the loss in energy of 5 keV He atoms that travel into and out of the liquid, which is then converted into depth. In the absence of NaBr, we find that THA+ and its Br– counterion segregate together because of charge attraction, forming a narrow double layer that is 10 Å wide and 150 times more concentrated than in the bulk. With the addition of NaBr, THA+ is “salted out” to the surface, increasing the interfacial Br– concentration by 3-fold and spreading the anions over a ∼30 Å depth. Added NaBr similarly increases the interfacial concentration of DS– ions and broadens their positions. Conversely, the dissolved Br– ions are significantly depleted over a depth of 0–40 Å from the surface because of charge repulsion from DS– ions within the interfacial region. These different interfacial Br– propensities correlate with previously measured gas–liquid reactivities: gaseous Cl2 readily reacts with Br– ions in the presence of THA+ but drops 70-fold in the presence of DS–, demonstrating that surfactant headgroup charge controls the reactivity of Br– through changes in its depth profile.

We report a DNA-templated synthesis method that allows construction of the entire DNA-encoded library with a single DNA template. Taking advantage of deoxyinosine's indiscriminate base-pairing property, we designed a "universal template" that is capable of directing chemical reactions with multiple reactant DNAs with different sequences. In combination with other design features including photocleavable linkers and direct encoding by the reactant DNA, we demonstrated the capabilities of the universal template in library synthesis, target selection, and hit decoding. Our method can be generally and straightforwardly applied to prepare a variety of chemically diverse DNA-encoded libraries.

Visible-light-induced living radical polymerization of acrylates (MA, nBA, tBA), acrylamides (DMA, AMO), and vinyl acetate (VAc) at ambient temperature mediated by (salen)Co(II)/TPO was described. Effects of light intensity, feeding ratio of monomer and equivalent of TPO for the polymerization of MA were investigated. Well-defined homopolymers and block polymers with predetermined molecular weight and narrow polydispersity were obtained under mild conditions. The mechanism of the polymerization was proposed based on polymerization behavior and polymer structure analysis. The (salen)Co(II)/TPO system was suitable for both conjugated and unconjugated monomers under mild conditions.