Kinetic Studies of Hantzsch Ester and Dihydrogen Donors Releasing Two Hydrogen Atoms in Acetonitrile.

In this work, kinetic studies on HEH, 2-benzylmalononitrile, 2-benzyl-1-indene-1,3(2)-dione, 5-benzyl-2,2-dimethyl-1,3-dioxane-4,6-dione, 5-benzyl-1,3-dimethylpyrimidine-2,4,6(1,3,5)-trione, 2-(9-fluoren-9-yl)malononitrile, ethyl 2-cyano-2-(9-fluoren-9-yl)acetate, diethyl 2-(9-fluoren-9-yl)malonate, and the derivatives (28 XH) releasing two hydrogen atoms were carried out. The thermokinetic parameters Δ ° of 28 dihydrogen donors (XH) and the corresponding hydrogen atom acceptors (XH) in acetonitrile at 298 K were determined. The abilities of releasing two hydrogen atoms for these organic dihydrogen donors were researched using their thermokinetic parameters Δ °(XH), which can be used not only to compare the H-donating ability of different XH qualitatively and quantitatively but also to predict the rates of HAT reactions.

Urea-doped carbon dots as fluorescent switches for the selective detection of iodide ions and their mechanistic study.

A facile and green strategy for the fabrication of fluorescent urea-doped carbon dots (N-CDs) has been explored. Significantly, the fluorescent N-CDs could recognize iodide ions (I) with high selectivity, and their photoluminescence could be efficiently quenched by the addition of I. The sensitivity analysis for I indicated a linear relationship in the range from 12.

Mechanism and Origins of Enantio- and Regioselectivities in Catalytic Asymmetric Minisci-Type Addition to Heteroarenes.

This work presents a density functional theory (DFT) study on the mechanism and origins of enantio- and regioselectivities in dual photoredox/chiral Brønsted acid-catalyzed asymmetric Minisci-type addition of carbon-centered radicals to N-heteroarenes [, , , 419-422]. The previously proposed mechanism has been partially revised. First, photoexcited *[Ir] is reductively quenched by TRIP anion rather than the experimentally proposed neutral radical generated from the chiral Brønsted acid cycle.

Two-Dimensional (001) LaAlO/SrTiO Heterostructures with Adjustable Band Gap and Magnetic Properties.

Very recently, freestanding crystalline perovskite films as thin as a single unit cell have been successfully synthesized, which expands the opportunities for research and applications of low-dimensional materials with novel functionalities. In this work, we constructed a series of two-dimensional (2D) (001) LaAlO/SrTiO heterostructures and systematically investigated their atomic and electronic properties by means of first-principles calculations. Our results show that (1) nonstoichiometry leads to ferromagnetism at the interfaces of the systems; (2) half-metallicity can be realized by introducing slight hole-doping; and (3) a semiconductor-to-metal transition can be triggered by applying a moderate (within 3%) out-of-plane strain.

Precise and Wide-Ranged Band-Gap Tuning of Ti-Core-Based Titanium Oxo Clusters by the Type and Number of Chromophore Ligands.

Sensitization with dyes is the most promising option to narrow the band gap and improve visible-light absorption of TiO. As ideal structure and reaction models of TiO, titanium oxo clusters (TOCs) with exact crystal structure are beneficial for further understanding the structure-property relationship of TiO. Most reports mainly focus on the synthesis and properties of TOCs, but research on the band-gap tuning of TOCs at the large range of 3.

A series of silver doped butterfly-like TiAg clusters with two Ag ions panelled on a Ti surface.

Silver doped TiO (Ag-TiO) materials show high activity and good stability in photocatalysis, but the mechanism could not be illustrated clearly due to their imprecise and inhomogeneous characteristics. Ag-doped titanium-oxo clusters (Ag-TOCs) with an exact crystal structure, which are rarely reported, are beneficial for further understanding structure-property relationships. Herein, six new Ag-TOCs with a butterfly-like TiAg core have been synthesized through facile solvothermal reactions, in which two Ag ions are successfully linked to the surface of the Ti core.

Atomic Resolution Insights into the Structural Aggregations and Optical Properties of Neat Imidazolium-Based Ionic Liquids.

A fundamental understanding of the structural heterogeneity and optical properties of ionic liquids is crucial for their potential applications in catalysis, optical measurement, and solar cells. Herein, a synergistic approach combining molecular dynamics simulations, excited-state calculations, and statistical analysis was used to explore the explicit correlation between the structural and optical properties of one imidazolium amino acid-based ionic liquid, 1-butyl-3-methylimidazolium glycine. The estimated absorption spectrum successfully rationalizes the unusual and non-negligible absorption band beyond 300 nm for the neat imidazolium-based ionic liquid.

Revised role of selectfluor in homogeneous Au-catalyzed oxidative C-O bond formations.

The pairing of transition metal catalysis with the reagent Selectfluor (F-TEDA-BF4) has attracted considerable attention due to its utility in myriad C-C and C-heteroatom bond-forming reactions. However, little mechanistic information is available for Selectfluor-mediated transition metal-catalyzed reactions and controversy surrounds the precise role of Selectfluor in these processes. We present herein a systematic investigation of homogeneous Au-catalyzed oxidative C-O bond-forming reactions using density functional theory calculations.