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[Display omitted] • The various hydrogen-bonded complexes involving the imidazol-2‑ylidene and its heavier congeners are investigated and compared. • Two types of hydrogen-bonded geometries can be located on the basis of the molecular electrostatic potential surfaces. • The relaxed potential energy surface scans were performed for some selected complexes. The hydrogen-bonded complexes formed between the imidazol-2‑ylidene and its heavier congeners C 2 H 4 N 2 T: (T = C, Si, Ge, Sn, Pb) and the three selected electron acceptors (HF, HCN and C 2 H 2) have been optimized at the aug-cc-pVTZ level, and the nature of these complexes has been investigated by natural bond orbital (NBO), atoms in molecules (AIM) and energy decomposition analyses. The complexes can be classified into type-A structure and type-B structure according to the location of the electron acceptors. The electron acceptors are around T atoms of C 2 H 4 N 2 T: for the type-A complexes, and the electron acceptors are above the five-membered ring (π-system) of C 2 H 4 N 2 T: for the type-B complexes. The electron-donating ability of T atoms becomes weaker, and that of π-systems becomes stronger when T atoms become heavier for C 2 H 4 N 2 T:, which is consistent with the molecular electrostatic potentials (MEP) maps of C 2 H 4 N 2 T:. For a given C 2 H 4 N 2 T:, the E int values of the type-A complexes go in the order HF > HCN > C 2 H 2 , and the E int values of the type-B complexes go in the order HF ≈ HCN > C 2 H 2. The contribution of electrostatic energy to the interaction energy of complexes becomes smaller for the type-A complexes when the T atoms become heavier. The interaction energies are dominated by the electrostatic energies for all the type-B complexes involving HF, and the interaction energies are dominated by the dispersion energies for most type-B complexes involving HCN and C 2 H 2. The relaxed potential energy surface scans were performed for some selected complexes involving HF and HCN to examine the difference in binding behavior between HF and HCN. [ABSTRACT FROM AUTHOR]

The metal-organic frameworks/cotton fabric composites (MOFs/CFCs) have emerged as a new type of prospective materials for environmental cleanup, due to their convenient recyclability and high removal efficiency towards hazardous pollutants. However, their practical applications are limited by complicated synthetic conditions, insufficient interface bonding and poor adsorption capacity. Herein, for the first time, a robust ethylenediaminetetraacetic acid (EDTA)-functionalized MOFs/CFC is prepared based on UiO-66-NH 2 crystals by using EDTA dianhydride as the cross-linking agent, and applied for simultaneous removal of heavy metals and dyes, as well as degradation of chemical warfare agents. The as-prepared EDTA-UiO-66-NH 2 /CFC shows extraordinary monocomponent adsorption performance with maximum adsorption capacity of 158.7, 126.2, 131.5, 117.4 and 104.5 mg/g for Cd(II), Cu(II), methylene blue, crystal violet and safranin O, respectively. Interestingly, in metal-dyes binary system, the uptake of Cu(II) by EDTA-UiO-66-NH 2 /CFC increases significantly when co-existing high concentration of dyes. The results indicate that the synergistic and simultaneous removal of both dyes and metal from complex systems can be realized by EDTA-UiO-66-NH 2 /CFC via multiple mechanisms. The EDTA-UiO-66-NH 2 /CFC also exhibits an outstanding catalytic performance for degrading dimethyl 4-nitrophenylphosphate. Besides, it can be reused for several times without obvious decrease of its adsorption and catalysis efficiencies. More impressively, the cross-linking reaction approach can not only anchor UiO-66-NH 2 crystals firmly onto cotton fabric, but also facilitate in-situ formation of abundant adsorption sties on the adsorbent surface. Therefore, this work offers a simple and versatile synthetic strategy to develop high-performance environmental material for multiple pollutants remediation. [Display omitted] • A simple and versatile synthetic strategy to develop high-performance environmental material. • Efficient and simultaneous adsorption of metal and dye pollutants. • EDTA dianhydride act as cross-linking agent and in-situ formation of chelating sites for metals. • EDTA-UiO-66-NH 2 /CFC exhibits excellent catalytic property in DMNP degradation. [ABSTRACT FROM AUTHOR]

Figures of persimmons for the world's top ten persimmon producing countries are about 4000,000 tons in 2011 and are increasing every year according to FAO statistics. However, there is not any report on pectin production by microbial with persimmon peel as the source. Optimization of fermentation conditions of pectin production from Aspergillus terreus in submerged culture and partial characterization of pectin were carried out in the work. An optimum fermentation condition for pectin production was obtained through a central composite rotatable design in response surface methodology as follows: fermentation time, 30.09 h, temperature, 25.00 °C and the initial pH in the fermentation medium, 6.90, respectively and the pectin yield reached the maximal value 0.449 g/g. Persimmon peel pectin had highly methoxylated (62.51%), high galacturonic acid content (82.28%) than citrus pectin, and was classified as the highly methoxylated pectin, the results indicated that persimmon peel had potential good resources for pectin production. The investigation can make it available to utilize persimmon peel to produce high methoxyl pectin for food industry, pharmacy and cosmetic manufacture. [ABSTRACT FROM AUTHOR]

Highlights: [•] The anion-binding ability of FH2As is stronger than that of FH2P. [•] The binding strength is in the sequence of SO4 2− >F− >Cl− >NO3 − >Br− >I−. [•] The anion-binding strength of pnicogen bonding is comparable to that of hydrogen and halogen bonding. [•] The anion-binding ability of pnicogen bonding can be strengthened through multiple receptor–anion interactions. [Copyright &y& Elsevier]

Abstract: The reactions of NbS+ (3∑−, 1Γ) with COS have been studied using density functional theory at the B3LYP level: the O/S exchange reaction (NbS+ +COS→NbO+ +CS2), the S-transfer reaction (NbS+ +COS→ +CO) and the O-transfer reaction (NbS+ +COS→ONbS+ +CS). The different mechanisms on the triplet and singlet surfaces have been identified. It is found that the S-transfer reaction has two parallel reaction paths (path A and path B) with respective to two isomeric products (-1 and -2), which may account, respectively, for the endothermic and the exothermic features of the product cross-section observed in the experiment. The spin-forbidden reaction NbS+ (3∑−)+COS→ (1-A′)+CO was found to be energetically much more favorable than the spin-allowed reaction NbS+ (3∑−)+COS→ (3-A′)+CO. According to the identified reaction mechanisms, a triplet–singlet surface crossing is suggested. The larger activation barriers (23.7 and 59.5kcal/mol) and the small probability of the formation of the preceding intermediate 3IM1 result in a much lower efficiency of the O/S exchange reaction and the O-transfer reaction of the 3∑− ground state of NbS+ with COS. For the O-transfer reaction, a triplet–singlet surface crossing may also exist. [Copyright &y& Elsevier]

Abstract: Uniform and monodispersed TiO2 hollow spheres with nanoporous titania shell are prepared successfully by using carboxyl-functionalized polystyrene spheres as templates. The results show that TiO2 hollow spheres pose a stable reversible capacity of 230 mAhg−1 at 33.5 mAg−1 and 120 mAhg−1 at 1675 mAg−1, which are higher than that of bulk TiO2 with coarse grain. The discharge process of TiO2 hollow spheres are suggested containing three consecutive stages: the formation of tetragonal Li x TiO2 solid solution, coexistence of two-phase mixture of Li0.05TiO2 and Li0.5TiO2 at 1.75 V and additional lithium storage in the surface. The superior high rate and high capacity performance of prepared TiO2 hollow spheres are due to its highly reversible additional surface capacities and accommodation of phase transformation within nanostructure. [Copyright &y& Elsevier]

Abstract: The reaction mechanism of the Mn+ (7 S and 5 S states) with COS has been studied by means of density functional method (B3LYP). The overall energetics has been refined at the CCSD (T) level. The calculated results indicate that both the C–S and C–O bond activations proceed via an insertion–elimination mechanism. The C–S bond activation is found to be much more favorable than the C–O bond activation. Intersystem crossing between the septuplet and quintet surfaces may occur along both the C–O and C–S bond activation branches. The calculated barriers of spin-forbidden reaction Mn+ (7 S)+COS→MnS+ (5 Π)+CO and spin-allowed reaction Mn+ (7 S)+COS→MnS+ (7 Π)+CO are 17.6 and 43.8kcal/mol, respectively, which are in good agreement with the values assigned in the experiment. [Copyright &y& Elsevier]