Capped chelating organic molecules are presented as a design principle for tuning heterogeneous nanoparticles for electrochemical catalysis. Gold nanoparticles (AuNPs) functionalized with a chelating tetradentate porphyrin ligand show a 110-fold enhancement compared to the oleylamine-coated AuNP in current density for electrochemical reduction of CO to CO in water at an overpotential of 340 mV with Faradaic efficiencies (FEs) of 93 %. These catalysts also show excellent stability without deactivation (<5 % productivity loss) within 72 hours of electrolysis. DFT calculation results further confirm the chelation effect in stabilizing molecule/NP interface and tailoring catalytic activity. This general approach is thus anticipated to be complementary to current NP catalyst design approaches.

Trifluoromethyl-containing compounds play a significant role in medicinal chemistry, materials and fine chemistry. Although direct C-H trifluoromethylation has been achieved on Csp -H bonds, direct conversion of Csp -H bonds to Csp -CF remains challenging. We report herein an efficient protocol for the selective trifluoromethylation of benzylic C-H bonds. This process is mediated by a combination Cu -CF species and persulfate salts. A wide range of methylarenes can be selectively trifluoromethylated at the benzylic positions. A combination of experimental and theoretical mechanistic studies suggests that the reaction involves a radical intermediate and a Cu -CF species as the CF transfer reagent.

Developing processes that allow partial oxidation of light alkanes (C 1 −C 4 ) to more valuable oxygenates is important from both industrial and academic perspectives. In this study, quantum mechanics combined with a constant potential model were employed to evaluate the ability of metal-N 4 -functionalized graphene (gMN 4 ) to catalyze anodic partial oxidation of light alkanes to oxygenates via electrochemical means while considering both reactivity and selectivity. During the reaction, reactive oxo (*O) is generated through water electrochemical oxidation. This reactive oxo is used to oxidize light alkanes (represented by methane and propane). On the basis of investigating the systems with different Ms (Cr, Mn, Fe, Co, Ru, Rh, Os, and Ir) in a wide range of electrode potentials (U, 0.0− 2.5 V SHE ) and pH values (0.0−14.0), only gIrN 4 and gFeN 4 were capable of catalyzing this oxidation with acceptable reaction rates. The other catalysts were unable to form *O or inert to C−H bonds. Both alkanes can be oxidized but the rate for methane is slower. gIrN 4 oxidizes methane to formaldehyde under proper Us. For propane, this catalyst generates iso-propanol at low Us and acetone at high Us. gFeN 4 only oxidizes propane to acetone. Our theoretical investigation along with known experimental results suggest a high probability for experimental realization of this anodic partial oxidation, which would allow for utilization of natural gas discovered in remote oil fields.

High-energy-density materials (HEDMs) containing the cyclopentazole anion (cyclo-N 5 ) are highly desirable due to the release of more energy and being environmentally more friendly than conventional HEDMs. However, the synthesis of stable cyclo-N 5 -containing HEDMs has been a challenge. In this study, quantum mechanical calculations were employed to elucidate the stability of [M(N 5 ) 2 (H 2 O) 4 ]•4H 2 O (M = Mn, Fe, Co, and Zn), one of the few recently reported cyclo-N 5 -contained HEDMs, under ambient conditions. The results from our study indicate that the stability is due to the presence of two types of water (coordinated H 2 O (c-H 2 O) and hydrogenbonded H 2 O (h-H 2 O)). Each type uses a unique mode to stabilize the highly reactive M(N 5 ) 2 cores. c-H 2 O binds with M to reduce the M ↔ cyclo-N 5 interaction, leading to a less activated cyclo-N 5 and higher kinetic barriers (E a s) for its decomposition. In contrast, h-H 2 O takes advantage of its permanent electrostatic interactions with cyclo-N 5 to inhibit the decomposition. The stabilizing effects of the two types of water on M(N 5 ) 2 are similar. On the basis of the lower energy cost to remove h-H 2 O from the materials and the subsequent large decrease in the E a due to this removal, we propose that h-H 2 O acts as a "safety device" that prevents the materials from becoming kinetically unstable. For future design of cyclo-N 5 -contained HEDMs, we proposed the use of various molecular building blocks, such as NH 3 , H 2 S, and PH 3 , which can tightly bind to M to reduce the M ↔ cyclo-N 5 interaction and impose permanent electrostatic interactions with cyclo-N 5 to provide the similar dual functions of H 2 O to suppress cyclo-N 5 decomposition.