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The drum-like C4nNn (n = 3-8) cages and corresponding hydrogenated products C4n H4nN2n (n = 3-8) are studied at the DFT B3LYP/6-31G** level. Their structures, energies, and vibrational frequencies have been investigated. Comparison of heat of formation reveals that C32N16 with D8h symmetry in the C4nN2n (n = 3-8) series is a promising candidate as high energy density matter. The calculation of the DeltaG and DeltaH for the hydrogenation of C4nN2n (n = 3-8) shows that it is an exothermic reaction at 298 K and the C4nH4nN2n (n = 3-8) species are more stable than C4nN2n (n = 3-8) species. The analysis of molecular orbital and selected bond lengths of N-N and C-C provides another insight about their stability. Combined with the nucleus-independent chemical shifts (NICS) calculation, it is indicated that molecular stability for cage-shaped molecules depends on not only aromatic character but also the cage effect.

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The adsorption and self-assembly of isocyanide derivatives on Au(111) surface were investigated by density functional theory (DFT) and molecular dynamics simulation. The calculation for phenyl isocyanide by DFT was based on cluster and slab models. The self-assembled monolayers of 2-isocyanoazulene and 1,3-diethoxycarbonyl-2-isocyanoazulene on Au(111) were simulated using Au-C force field parameters developed by us. It was found that the top site was the most preferred position, and the isocyanoazulene and its derivatives could form the ordered face to edge self-assembled monolayer on gold surface indeed, and the molecules stood on the gold surface vertically.

Nitroaromatics are tremendously valuable organic compounds with a long history of being used as pharmaceuticals, agrochemicals, and explosives as well as vital intermediates to a wide variety of chemicals. Consequently, the exploration of aromatic nitration has become an important endeavor in both academia and industry. Herein, we report the identification of a powerful nitrating reagent, 5-methyl-1,3-dinitro-1 H -pyrazole, from the N -nitro-type reagent library constructed using a practical N–H nitration method. This nitrating reagent behaves as a controllable source of the nitronium ion, enabling mild and scalable nitration of a broad range of (hetero)arenes with good functional group tolerance. Of note, our nitration method could be controlled by manipulating the reaction conditions to furnish mononitrated or dinitrated product selectively. The value of this method in medicinal chemistry has been well established by its efficient late-stage C–H nitration of complex biorelevant molecules. Density functional theory (DFT) calculations and preliminary mechanistic studies reveal that the powerfulness and versatility of this nitrating reagent are due to the synergistic “nitro effect” and “methyl effect”.

The self-assembled monolayers (SAMs) of 1-adamantanethiolate and its derivatives on Au(111) surface were investigated. Density functional theory (DFT) calculation indicates that the most stable configuration for absorption is at the face centered cubic (fcc)-bridge site. Canonical ensemble molecular dynamics (MD) simulations were carried out to study the structures and energies of the SAMs. The ordered structures of the SAMs were analyzed by means of radial distribution function and the relative stability of the SAMs was compared. It was concluded by the comparison of various contributions to the SAM formation energy that the formation of the SAMs was determined by the intermolecular nonbonding interaction and the chemical bonding interaction of sulfur and gold.

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