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The reaction between HONO and HCl is a possible pathway for the generation of ClNO, which is prone to photolyze, produce chlorine radicals, and accelerate the oxidation of tropospheric VOCs. Current experimental and theoretical studies have significant differences in rate constants under similar conditions. This study aims to examine the reasons for this difference. In this study, the effects of a single water molecule, water dimer, water trimer, excess HCl and excess HONO on the reaction mechanism of HONO + HCl were studied at the CCSD(T)/aug-cc-pVTZ//M06-2X/6-311+G(2df,2p) level and the rate constants of each reaction channel were calculated. Our results showed that the reaction potential barrier of HONO with HCl was the lowest only when the water dimer was present, and the reaction rate constants were close to the experimental results, and both the cis-HONO⋯(H2O)2 + HCl and the trans-HONO⋯(H2O)2 + HCl reaction paths are likely to occur. We think that the reason for the inconsistency between experimental and theoretical results is that the water dimer is involved in the reaction in experiments. [ABSTRACT FROM AUTHOR]

Y2C2@C82 series (as well as Y2@C84 series) and the parent C82 cages were investigated by density functional theory in conjunction with statistical thermodynamic analyses. C2(39717)‐C82 is the most stable isomer of pristine C82 cages, and Y2@D2d(51591)‐C84 is the most low‐lying isomer of Y2C84 series. At the temperature range of fullerene formation, C2(39712)‐C82, Cs(39713)‐C82, and C3v(39717)‐C82 are the three most abundant C82 isomers, and Y2C2@Cs(39715)‐C82, Y2C2@C3v(39717)‐C82, and Y2C2@C2v(39718)‐C82 are the three only abundant Y2C84 isomers. However, mole fraction of Y2@D2d(51591)‐C84 turns to be very low at the high temperature range. Further statistical thermodynamic analyses revealed that vibrational frequencies are the underlying reason for high abundances of Y2C2@Cs(39715)‐C82, Y2C2@C3v(39717)‐C82, and Y2C2@C2v(39718)‐C82 and low abundance of Y2@D2d(51591)‐C82 at high temperature range. The statistical thermodynamic analysis approach to separately consider energy, rotation and vibration partition functions can be used to investigate other endohedral metallofullerenes. [ABSTRACT FROM AUTHOR]

Nanocarbon oxides have been proved to possess great peroxidase-like activity, catalyzing the oxidation of many peroxidase substrates, such as 3,3′,5,5′-tetramethylbenzidine (TMB) and o-phenylenediamine dihydrochloride (OPD), accompanied by a significant color change. This chromogenic reaction is widely used to detect glucose and occult blood. The chromogenic reaction was intensively investigated with density functional theory and molecular-level insights into the nature of peroxidase-like activity were gained. A radical mechanism was unraveled and the carboxyl groups of nanocarbon oxides were identified as the reactive sites. Aromatic domains connected with the carboxyl groups were critical to the peroxidase-like activity. [ABSTRACT FROM AUTHOR]

The reaction between HONO and HCl is a possible pathway for the generation of ClNO, which is prone to photolyze, produce chlorine radicals, and accelerate the oxidation of tropospheric VOCs. Current experimental and theoretical studies have significant differences in rate constants under similar conditions. This study aims to examine the reasons for this difference. In this study, the effects of a single water molecule, water dimer, water trimer, excess HCl and excess HONO on the reaction mechanism of HONO + HCl were studied at the CCSD(T)/aug-cc-pVTZ//M06-2X/6-311+G(2df,2p) level and the rate constants of each reaction channel were calculated. Our results showed that the reaction potential barrier of HONO with HCl was the lowest only when the water dimer was present, and the reaction rate constants were close to the experimental results, and both the cis -HONO⋯(H 2 O) 2 + HCl and the trans -HONO⋯(H 2 O) 2 + HCl reaction paths are likely to occur. We think that the reason for the inconsistency between experimental and theoretical results is that the water dimer is involved in the reaction in experiments.

Nonclassical fullerene is a new member of the fullerene family. In the present work, a systematic investigation on La x Sc 3- x N@C 80 ( x = 0-3) covering both classical and nonclassical C 80 cages was performed utilizing density functional theory combined with statistical mechanics. At absolute zero, LaSc 2 N@ Hept(6) - C s (2)-C 80 with a heptagon-containing nonclassical carbon is the second most stable isomer, whereas at the temperature range of endohedral metallofullerene (EMF) formation, due to the large vibrational frequencies, LaSc 2 N@ Hept(6) - C s (2)-C 80 is the third most abundant isomer, and its mole fraction is very low, accounting for the low experimental yield of LaSc 2 N@ Hept(6) - C s (2)-C 80 ; La 2 ScN@ Hept(6) - C s (2)-C 80 , and La 3 N@ Hept(6) - C s (2)-C 80 are the overwhelming isomers of the corresponding series, but compared with the cases of Sc 3 N@C 80 and LaSc 2 N@C 80 , La 2 ScN and La 3 N clusters suffer much larger constraints from the C 80 cages, perhaps preventing the synthesis of La 2 ScN@C 80 and La 3 N@C 80 species. Because of the large mole fractions and large electron donation and back-donation of La 2 ScN@ Hept(6) - C s (2)-C 80 and La 3 N@ Hept(6) - C s (2)-C 80 , it can be inferred that La 2 ScN and La 3 N clusters may be used to stabilize some other larger nonclassical fullerene cages. This work will provide useful insights into the origins of stabilization of nonclassical fullerene cages by endohedral derivation and guidelines for synthesis EMF with nonclassical cages.

Transition-metal disulfide with its layered structure is regarded as a kind of promising host material for sodium insertion, and intensely investigated for sodium-ion batteries. In this work, a simple solvothermal method to synthesize a series of MoS 2 nanosheets@nitrogen-doped graphene composites is developed. This newly designed recipe of raw materials and solvents leads the success of tuning size, number of layers, and interplanar spacing of the as-prepared MoS 2 nanosheets. Under cut-off voltage and based on an intercalation mechanism, the ultrasmall MoS 2 nanosheets@nitrogen-doped graphene composite exhibits more preferable cycling and rate performance compared to few-/dozens-layered MoS 2 nanosheets@nitrogen-doped graphene, as well as many other reported insertion-type anode materials. Last, detailed kinetics analysis and density functional theory calculation are also employed to explain the Na + - storage behavior, thus proving the significance in surface-controlled pseudocapacitance contribution at the high rate. Furthermore, this work offers some meaningful preparation and investigation experiences for designing electrode materials for commercial sodium-ion batteries with favorable performance., (© 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

A family of dilanthanum-containing endohedral metallofullerene La 2 C 2n (n = 46-51) was synthesized recently. In the present work, a systematical investigation on La 2 C 96 series including the carbide clusterfullerene form La 2 C 2 @C 94 and the conventional dimetallofullerene form La 2 @C 96 was implemented by density functional theory, combined with statistical mechanics. Three isomers, i.e., La 2 @D 2 (191838)-C 96 , La 2 C 2 @C s (153479)-C 94 , and La 2 C 2 @C 1 (153491)-C 94 were disclosed to be thermodynamically stable at the temperature region of endohedral metallofullerene formation. La 2 @D 2 (191838)-C 96 is the prevailing isomer at low temperature, while La 2 C 2 @C s (153479)-C 94 and La 2 C 2 @C 1 (153491)-C 94 are the most and second-most abundant isomers at high temperature. Interestingly, the highest occupied molecular orbital (HOMO) of La 2 C 2 @C 1 (153491)-C 94 is distributed on one pole of the cage, and the lowest unoccupied molecular orbital (LUMO) of this isomer is mainly located on the equator of the cage, which can facilitate synthesis of regioselective derivatives. This work will provide useful information for further experimental identification and application of La 2 C 96 .