Chiral electron deficient ruthenium helical coordination polymer as a catalyst for the epoxidation of substituted styrenes

An air and moisture stable ruthenium（Ⅲ） formate complex[Ru（HCO2）Cl2]n has been synthesized and examined in the epoxidation of substituted styrenes.X-ray crystallographic data of this complex were determined and showed that the formate ligand coordinates to the ruthenium centers in a μ~2-η~2 fashion（syn,syn）.Its asymmetric unit contains one Ru（Ⅲ） ion together with the half of a formate ligand and one chloride anion,which are bridged between the metal centers,forming a 1-D chain coordination polymer.This electron deficient helical coordination polymer was employed in the epoxidation of parafluorostyrene,affording the epoxide product in 92%yield.Natural chirality of this coordination polymer is applicable in asymmetric epoxidation reactions.

Amination of electron deficient aryl chlorides promoted by nano sized Mg(OH)_2 under transition metals free condition

This paper presents the amination reactions of electron deficient aryl chlorides promoted by Mg（OH）_2 without transition metals. Only using stoichiometric amount of nano sized Mg（OH）_2,good to moderate isolated yields could be achieved in N-methylpyr-rolidone （NMP） after 24 h at 150℃.

Highly surface electron-deficient Co_(9)S_(8) nanoarrays for enhanced oxygen evolution

Tailoring valence electron delocalization of transition metal center is of importance to achieve highly-active electrocatalysts for oxygen evolution reaction(OER).Herein,we demonstrate a“poor sulfur”route to synthesize surface electron-deficient Co_(9)S_(8) nanoarrays,where the binding energy(BE)of Co metal center is considerably higher than all reported Co_(9)S_(8)-based electrocatalysts.The resulting Co_(9)S_(8) electrocatalysts only require the overpotentials(h)of 265 and 326 mV at 10 and 100 mA cm^(-2) with a low Tafel slope of 56 mV dec^-(1) and a 60 hlasting stability in alkaline media.The OER kinetics are greatly expedited with a low reaction activation energy of 27.9 kJ mol^-(1) as well as abundant OOH*key intermediates(24%),thus exhibiting excellent catalytic performances.The surface electron-deficient engineering gives an available strategy to improve the catalytic activity of other advanced non-noble electrocatalysts.

Inverse Halogen Bonds Interactions Involving Br Atom in the Electronic Deficiency Systems of CH3＋… Br-Y （Y--H, CCH, CN, NC）

Inverse halogen bonds interactions involving Br in the electronic deficiency systems of CH3＋...Br-Y （Y=H, CCH, CN, NC） have been investigated by B3LYP/6- 311＋＋G（d, p） and MP2/6-311＋＋G（d, p） methods. The calculated interaction energies with basis set super-position error correction of the four IXBs complexes are 218.87, 219.48, 159.18, and 143.05kJ/mol （MP2/6-311＋＋G（d, p））, respectively. The relative stabilities of the four complexes increased in the order： CH3＋ … BrCN〈CH3＋…- BrNC〈CH3＋… BrH≈CH3＋ …BrCCH. Natural bond orbital theory analysis and the chemical shifts calculation of the related atoms revealed that the charges flow from Br-Y to CH3e. Here, the Br of Br-Y acts as both a halogen bond donor and an electron donor. Therefore, compared with conventional halogen bonds, the IXBs complexes formed between Br-Y and CH3＋. Atoms-in-molecules theory has been used to investigate the topological properties of the critical points of the four IXBs structures which have more covalent content.

Promoting selective electroreduction of nitrates to ammonia over electron-deficient Co modulated by rectifying Schottky contacts

Developing efficient electrocatalysts for selective nitrate contamination reduction into value-added ammonia is significant.Here,heterostructured Co/CoO nanosheet arrays(Co/CoO NSAs)exhibited excellent Faradaic efficiency(93.8%)and selectivity(91.2%)for nitrate electroreduction to ammonia,greatly outperforming Co NSAs.15N isotope labeling experiments and 1H nuclear magnetic resonance(NMR)quantitative testing methods confirmed the origin of the produced ammonia.Electrochemical in situ Fourier transform infrared(FTIR)spectroscopy,online differential electrochemical mass spectrometry(DEMS)data and density functional theory(DFT)results revealed that the superior performances arose from the electron deficiency of Co induced by the rectifying Schottky contact in the Co/CoO heterostructures.The electron transfer from Co to CoO at the interface could not only suppress the competitive hydrogen evolution reaction,but also increase energy barriers for by-products,thus leading to high Faradaic efficiency and selectivity of ammonia.

Ab initio Studies on Boron Clusters and Their Corresponding Boranes with T_d,O_h and I_h Symmetries

The thermal stability and bonding characteristics of the larger boron clusters B n and their corresponding boranes with T d , O h or I h symmetries were studied by means of ab initio method. The results obtained from the calculation show that the clusters and boranes are all thermally stable to a different extent. The number of the skeletal bonding orbitals of B n H 2- n satisfies the Wades rule, but this kind of clusters need not be a complete triangular face polyhedron. The results also indicate that the larger neutral boranes B n H n may exist.

Accelerating the Activation of NO_(x)^(−)on Ru Nanoparticles for Ammonia Production by Tuning Their Electron Deficiency

Stable and portable ammonia(NH3)is a promising,low-cost,and environment-friendly medium for energy storage.How to achieve the rapid production of NH3 from reducing NO_(x)^(−)in aqueous systems and industrial wastewater via electrochemical methods remains the main challenge for practical application on a large scale.The corresponding electrocatalysts as the key materials in electrochemical devices suffer from low activity,especially in neutral systems.In this work,we successfully elevated the activity of the bench-mark Ru electrocatalysts to more than 30 times via construction of rectifying contact of Ru metals and noble carbons.We theoretically predicted and then rationally designed a new type of P-O rich carbon with large work functions as“noble”supports to attract a pronounced number of electrons from Ru metals at the rectifying interface.The resulting electron deficiency of Ru metals largely promotes the pre-adsorption and activation of NO_(x)^(−)anions,providing high Faradaic efficiencies(>96%)and record-high turnover frequency values for universal NO_(2)^(−)and NO_(3)^(−)reduction in neutral solution.