Chemical Science

List of Papers (Total 4,436)

Contact electrification induced interfacial reactions and direct electrochemical nanoimprint lithography in n-type gallium arsenate wafer.

Although metal assisted chemical etching (MacEtch) has emerged as a versatile micro-nanofabrication method for semiconductors, the chemical mechanism remains ambiguous in terms of both thermodynamics and kinetics. Here we demonstrate an innovative phenomenon, ...

Differences between the elimination of early and late transition metals: DFT mechanistic insights into the titanium-catalyzed synthesis of pyrroles from alkynes and diazenes.

Early transition metals (TMs), such as titanium, generally resist undergoing reductive elimination to form C–X bonds due to their weak electronegativity. By analyzing the mechanism of the titanium-catalyzed synthesis of pyrroles from alkynes and ...

Pairwise hydrogen addition in the selective semihydrogenation of alkynes on silica-supported Cu catalysts.

Mechanistic insight into the semihydrogenation of 1-butyne and 2-butyne on Cu nanoparticles supported on partially dehydroxylated silica (Cu/SiO[2-700] ) was obtained using parahydrogen. Hydrogenation of 1-butyne over Cu/SiO[2-700] yielded 1-butene with ...

Cobalt catalyzed carbonylation of unactivated C(sp3)-H bonds.

A general efficient regioselective cobalt catalyzed carbonylation of unactivated C(sp[3] )–H bonds of aliphatic amides was demonstrated using atmospheric (1–2 atm) carbon monoxide as a C1 source. This straightforward approach provides ...

A new class of Cu/ZnO catalysts derived from zincian georgeite precursors prepared by co-precipitation.

Zincian georgeite, an amorphous copper–zinc hydroxycarbonate, has been prepared by co-precipitation using acetate salts and ammonium carbonate.Zincian georgeite, an amorphous copper–zinc hydroxycarbonate, has been prepared by co-precipitation ...

CO/CO and NO/NO coupling at a hidden frustrated Lewis pair template.

N-Allyltetramethylpiperidine is readily isomerized to the corresponding enamine by treatment with catalytic amounts of B(C[6] F[5] )[3] . It adds HB(C[6] F[5] )[2] at the nucleophilic enamine carbon atom to form a C/B Lewis adduct. This reacts with ...

Fabrication and nanostructure control of super-hierarchical carbon materials from heterogeneous bottlebrushes.

Advances in the performances of many modern materials fundamentally depend upon the exploitation of new micro/nanostructures. Therefore, ingenious design of hierarchical structures through the mimicking of natural systems is of increasing importance. ...

Molecular engineering and sequential cosensitization for preventing the "trade-off" effect with photovoltaic enhancement.

In dye-sensitized solar cells (DSSCs), it is essential to use rational molecular design to obtain promising photosensitizers with well-matched energy levels and narrow optical band gaps. However, the “trade-off” effect between the photocurrent ...

Coevolution and ratiometric behaviour in metal cation-driven dynamic covalent systems.

Dynamic Covalent Libraries (DCLs) have been used to demonstrate coevolution behaviour on a molecular level using dynamic covalent molecules such as imines and hydrazones. Two systems are presented: the first system is based on a dialdehyde and two diamines ...

Versatile routes for synthesis of diarylamines through acceptorless dehydrogenative aromatization catalysis over supported gold-palladium bimetallic nanoparticles.

Diarylamines are an important class of widely utilized chemicals, and development of diverse procedures for their synthesis is of great importance. Herein, we have successfully developed novel versatile catalytic procedures for the synthesis of diarylamines ...

In situ observation of reactive oxygen species forming on oxygen-evolving iridium surfaces.

Water splitting performed in acidic media relies on the exceptional performance of iridium-based materials to catalyze the oxygen evolution reaction (OER). In the present work, we use in situ X-ray photoemission and absorption spectroscopy to resolve ...

Triflimide-catalyzed allylsilane annulations of benzylic alcohols for the divergent synthesis of indanes and tetralins.

The development of a triflimide-catalyzed annulation of benzylic alcohols with allylsilanes for the divergent synthesis of indane or tetralin structures from common precursors is reported.The development of a triflimide-catalyzed annulation of benzylic ...

Continuous variables logic via coupled automata using a DNAzyme cascade with feedback.

The concentration of molecules can be changed by chemical reactions and thereby offer a continuous readout. Yet computer architecture is cast in textbooks in terms of binary valued, Boolean variables. To enable reactive chemical systems to compute we ...

Simultaneous construction of two linkages for the on-surface synthesis of imine-boroxine hybrid covalent organic frameworks.

The orthogonality between the Schiff base reaction and the boronic acid dehydration reaction is explored during the on-surface synthesis process. By activating the above two reactions in one-step and employing asymmetrical substituted monomers and the ...

CO/O2 assisted oxidative carbon-carbon and carbon-heteroatom bond cleavage for the synthesis of oxosulfonates from DMSO and olefins.

Selective carbon–carbon and carbon–heteroatom bond cleavage was achieved in a one reaction system.Selective carbon–carbon and carbon–heteroatom bond cleavage was achieved in a one reaction system. With this strategy a ...

Mechanism of photocatalytic water oxidation on small TiO2 nanoparticles.

Nonadiabatic molecular dynamics simulations suggest an excited state electron proton transfer mechanism and explain the observation of mobile hydroxyl radicals.We present the first unconstrained nonadiabatic molecular dynamics (NAMD) simulations of photocatalytic ...

AIEgen-based theranostic system: targeted imaging of cancer cells and adjuvant amplification of antitumor efficacy of paclitaxel.

An AIEgen-based theranostic system is developed to amplify the antitumor efficacy of paclitaxel with a synergistic effect of “0 + 1 > 1”.Photosensitizers are generally treated as key components for photodynamic therapy. In contrast, ...

Highly specific C-C bond cleavage induced FRET fluorescence for in vivo biological nitric oxide imaging.

A novel Förster resonance energy transfer (FRET) fluorescence “off–on” system based on the highly specific, sensitive and effective C–C bond cleavage of certain dihydropyridine derivatives was reported for real-time ...

Formation mechanism of overlapping grain boundaries in graphene chemical vapor deposition growth.

The formation of grain boundaries (GBs) in graphene films is both fundamentally interesting and practically important for many applications. A GB in graphene is known as a linear defect and is formed during the coalescence of two single crystalline graphene ...

Pentafluorobenzene end-group as a versatile handle for para fluoro "click" functionalization of polythiophenes.

A convenient method of introducing pentafluorobenzene (PFB) as a single end-group in polythiophene derivatives is reported via in situ quenching of the polymerization. We demonstrate that the PFB-group is a particularly useful end-group due to its ability ...

Prediction of superconducting iron-bismuth intermetallic compounds at high pressure.

The synthesis of materials in high-pressure experiments has recently attracted increasing attention, especially since the discovery of record breaking superconducting temperatures in the sulfur–hydrogen and other hydrogen-rich systems. Commonly, ...

[Ag115S34(SCH2C6H4t Bu)47(dpph)6]: synthesis, crystal structure and NMR investigations of a soluble silver chalcogenide nanocluster.

The soluble 115 nuclear silver cluster [Ag[115] S[34] (SCH[2] C[6] H[4] [t] Bu)[47] (dpph)[6] ] was synthesized and fully characterized in solution and in the solid state.With the aim to synthesize soluble cluster molecules, the silver salt of (4-(tert-butyl)phenyl)methanethiol ...

An albumin-based tumor-targeted oxaliplatin prodrug with distinctly improved anticancer activity in vivo.

The design of targeted platinum() prodrugs is a very promising approach to enhance the low selectivity of platinum() drugs towards cancerous tissue in order to reduce the impact on healthy tissue and, consequently, the often severe side-effects. Herein, ...

Complementary oligonucleotides regulate induced fit ligand binding in duplexed aptamers.

Duplexed aptamers (DAs) are engineered by hybridizing an aptamer-complementary element (ACE, e.g. a DNA oligonucleotide) to an aptamer; to date, ACEs have been presumed to sequester the aptamer into a non-binding duplex state, in line with a conformational ...

SABRE hyperpolarisation of vitamin B3 as a function of pH.

NMR sensitivity enhanced through SABRE hyperpolarisation and pH manipulation enables the use of vitamin B3 as a pH probe.In this work we describe how the signal enhancements obtained through the SABRE process in methanol-d [4] solution are significantly ...