Direct S2 or S2X Manifold─Mechanistic Study of Ion-Pair-Catalyzed Carbon(sp)-Carbon(sp) Bond Formation.

Density functional theory (DFT) is used in this work to predict the mechanism for constructing congested quaternary-quaternary carbon(sp)-carbon(sp) bonds in a pentanidium-catalyzed substitution reaction. Computational mechanistic studies were carried out to investigate the proposed S2X manifold, which consists of two primary elementary steps: halogen atom transfer (XAT) and subsequent S2. For the first calculated model on original experimental substrates, XAT reaction barriers were more kinetically competitive than an S2 pathway and connect to thermodynamically stable intermediates.

Biodissolution and Cellular Response to MoO3 Nanoribbons and a New Framework for Early Hazard Screening for 2D Materials.

Two-dimensional (2D) materials are a broad class of synthetic ultra-thin sheet-like solids whose rapid pace of development motivates systematic study of their biological effects and safe design. A challenge for this effort is the large number of new materials and their chemical diversity. Recent work suggests that many 2D materials will be thermodynamically unstable and thus non-persistent in biological environments.

Resting state and task-related brain dynamics supporting insight.

Problems can be solved in a variety of ways. One might systematically evaluate a known space of possible solutions until the right one is found. Alternatively, it may prove necessary to enlarge or restructure the expected problem space - so called "thinking outside the box.