We have investigated electronic and transport properties of a novel form of [V(Bz)2]n@SWCNT and [V(Bz)2]n@DWCNT nanocables by means of DFT and NEGF methods. We find that endohedral encapsulation of [V(Bz)2]n into SWCNT or DWCNT is energetically favorable. Both nanocables exhibit strong magnetism and their ferromagnetic state is predicted to have a very high Curie or Neél temperature of over 1100 K, suggesting a potential candidate as magnetic nanopart. [V(Bz)2]n@SWCNT and [V(Bz)2]n@DWCNT show metallic property with a little spin dependent character: spin-down state gives a slight higher conductivity than the spin-up state due to the half-metallic character of the core [V(Bz)2]n. We also find that multiple transport channels coexist in [V(Bz)2]n@DWCNT: half-metallic channel of [V(Bz)2]n, direct main metallic channel of inner CNT, indirect hopping channel between inner and outer CNTs. Encapsulating [V(Bz)2]n into either SWCNT or DWCNT can effectively tune electronic and transport properties and these nanocables can be potentially used as functional nanodevices.

•A subtle competition between lp⋯π interaction and hydrogen bond of titled complexes has been studied theoretically.•The combination of hydrogen bonding and lp⋯π interaction controls the structures of complexes.•Novel non-covalent C⋯N carbon bonding is observed in the TNT⋯NH3 complex.•New IR absorption peak of the complexes may be helpful for the detection of TNT.A theoretical study of the interactions between 2,4,6-trinitrotoluene (TNT) and ammonia (NH3) has been carried out by means of MP2, DFT, and CCSD(T) methods. Eight stable structures of TNT⋯NH3 complexes were identified at the MP2/6-311++G(d,p) level. Various interactions such as lone pair⋯π interaction (lp⋯π interaction), conventional NH⋯O, CH⋯N, N–H···π hydrogen bonds, and novel noncovalent C⋯N carbon bonding, have been observed in the titled complexes. The competition between hydrogen bonding and lp⋯π interaction in the complexes was studied and discussed. The attractive lp⋯π interactions are observed when the lone pair of NH3 points toward TNT π ring. At the CCSD(T)/6-311++G(d,p)//MP2/6-311++G(d,p) level, the corresponding BSSE corrected interaction energy (ΔE) is −3.7 kcal mol−1. The calculated results also show that the lp⋯π interaction competes successfully with the NH⋯π and NH⋯O hydrogen bonds. The competition between hydrogen bonding and lp⋯π interaction in TNT⋯NH3 complexes plays important role to affect the structures of complexes. However, the conventional CH⋯N hydrogen bond is stronger than the lp⋯π interaction. The complex I merely with CH⋯N hydrogen bond is the most stable structure among eight complexes. The theoretical studies on UV and IR spectra of the TNT⋯NH3 complexes show that the formations of hydrogen bonding and lp⋯π interaction have small effect on the UV spectra but new IR absorption peaks in range of 100–300 cm−1 correlated to interactions between TNT and NH3 have been predicted, which may be helpful for the detection of TNT.

•Novel chalcogen-doped organic semiconductors (OSCs) have been studied theoretically.•The results show that two derivatives are promising candidates for ambipolar OSCs.•The selected derivatives exhibit remarkable anisotropic behaviors.Triisopropylsilylethynyl(TIPS)-functionalized polyacenes, a new family of novel organic semiconductors, have attracted extensive interests due to their high solubility, good air stability, and high performance in organic field effect transistors (OFETs). In present study, the electronic and charge transport properties of a series of chalcogen-doped TIPS-pentacene (PENT) derivatives have been studied by density functional theory (DFT). Their electronic structures, ionization energies, electron affinities, reorganization energies, transfer integrals of possible hopping pathways, hole and electron mobilities, and anisotropic mobilities have be calculated to discuss the role of various factors affecting the charge transport properties of these novel organic semiconductors. Fluorination and chlorination effects on the electronic properties and reorganization energies of the studied molecules have also been studied. The calculated results show that the fluorination and chlorination are efficient strategies for tuning the molecular orbital level to decrease the charge injection barrier from metal electrode and improve their oxidative stabilities. Though the fluorination indeed lowers the lowest unoccupied molecular orbital (LUMO) levels of TIPS-PENT derivatives, it also leads to much larger reorganization energies and smaller electron transfer integrals. Thus, it may be not an effective way for TIPS-PENT derivatives to convert a p-type semiconductor to an n-type one. Our calculated hole mobilities for available experiment crystal structures are in good agreement with the experimental observation. The computed hole mobilities for TIPS-anthradithiophene (ADT) and TIPS-teracenothiophene (TT) are 0.622 and 1.186 cm2 V−1 s−1, respectively, which are in good agreement with the corresponding experimental values of 0.6 and 1.25 cm2 V−1 s−1, respectively. Their relative calculated electron mobilities are 0.607 and 0.637 cm2 V−1 s−1, respectively. The results show that they have high balanced hole and electron mobilities and may be promising candidates for ambipolar organic semiconductors. The studies on anisotropic mobilities of the selected derivatives show that they exhibit remarkable anisotropic behaviors and the hole and electron transfers along the parallel hopping pathway make the dominant contribution on their charge carrier mobilities.

A novel BINOL-based ratiometric fluorescent sensor (R2) is presented, which can selectively respond to Zn2+ over Cd2+ and other metal ions with fluorescence enhancement in aqueous solution. The R2 was successfully applied in the imaging of Zn2+ in living cells. Additionally, the in situ generated R2-Zn(II) ensemble could further serve as a probe to distinguish histidine from other amino acids via a displacement mode.

•Nine new nitrogen lp⋯π interactions systems have been reported for the first time.•Strong new attractive nitrogen lp⋯π interaction are observed.•The present studies show how to manipulate and obtain strong lp⋯π interaction.For a better understanding of the interesting lone pair⋯π (lp⋯π) interaction, MP2 and CCSD(T) calculations have been carried out to investigate the nitrogen lp⋯π interactions between amine and tri-s-triazine derivatives. New strong attractive lp⋯π interactions are observed when the lone pairs of NH3 and NMe3 point toward the large π system, tri-s-triazine ring. At the CCSD(T)/6-311++G(d,p)//MP2/6-311G(d,p) level, the BSSE corrected interaction energy of the C6N7H3⋯NH3 complex is −6.3 kcal mol−1,which is larger than those of the most previously reported lp⋯π systems. The substitution effects on interaction energy of the present studied systems were studied to probe how to manipulate lp⋯π interaction and obtain stronger one. The results indicate that the very strong lp⋯π interaction can form between electron-rich amines and electron-deficient large aromatic ring. But the lp⋯π interactions between the electron-deficient amine such as NF3 and aromatic ring are very weak. The C6N7F3⋯NMe3 complex has interaction energy of −9.8 kcal mol−1. This interaction is much stronger than previously reported lp⋯π bindings. The AIM analysis of the nine studied complexes shows that their molecular graphs are obvious different from previously reported benzene⋯amine complexes and X–H/π systems, which may result from the tri-s-triazine ring’s characteristic.

Counterintuitive amine lone pair⋯π interactions are computationally revealed by MP2 and CCSD(T) methods, attractive lone pair⋯π interactions are observed when the lone pair of nitrogen points toward the π system. Symmetry adapted perturbation theory (SAPT) calculations and atoms in molecules (AIM) analyses were performed and the origin of the calculated attractive interaction between nitrogen lone pairs and π rings is discussed. Dispersion effects were revealed to play a crucial role in the attractive lone pair⋯π interaction.

A highly enantioselective Strecker reaction of difluoromethyl and trifluoromethyl ketoimines was developed. Remarkable fluorine effect on the reactivity and selectivity is observed and discussed.

High level G3(MP2B3) calculations have been performed to study the structures and properties of [n]silaprismanes and poly[n]silaprismanes. The similarity and differences of these molecules were systematically studied in terms of their structures, binding energy, strain energy, heat of formation, and HOMO–LUMO gaps, etc. Our calculations reveal that the five-membered silaprismane (n = 5) have relatively high stability among the [n]silaprismanes studied. Considering that only the three- (n = 3) and four-membered (n = 4) silaprismane derivatives have been synthesized up to now, our calculations provide an interesting target for future synthesis. In addition, we designed a series of multi-layer silaprismane whose HOMO–LUMO gaps decrease with the number of layers. It is then expected that the silicon nanotubes are semi-conductive with small HOMO–LUMO gaps. The comparisons between silaprismane and hydrogenated silicon fullerene were also made and discussed.

The reaction mechanisms of Ag and Au atoms with CS2 on both doublet and quartet potential energy surfaces (PESs) have been investigated using UBPW91 and UCCSD(T) methods. The two studied reactions proceed via a similar insertion–elimination mechanism instead of a direct abstract mechanism. The reaction Ag + CS2 → SAgCS is endothermic by about 21.0 kcal/mol. But another reaction Au + CS2 → SAuCS is slightly exothermic by about 8.8 kcal/mol, which is different from the previous theoretical prediction. In the overall reactions, the rate-determining step is found to be the C–S bond cleavage step with a high-activation barrier of about 40 kcal/mol. The calculated vibration frequencies are in good agreement with the experiment values and show that the BPW91 method is very good for the calculation of small molecules containing Ag and Au. The reactivity of the two atoms toward CS2 is compared with those of the first-row transition-metal atoms. The present study provides a detailed picture of the C–S bond activation and cleavage in carbon disulfide mediated by second and the third row transition-metal atoms Ag and Au.

A Gaussian-3 theory investigation using B3LYP geometries is carried out to examine N4H4 isomers. Eleven species are found, six of which are reported for the first time. The structures, stabilities, thermochemical properties, and tautomerism between them are studied and discussed. The most stable N4H4 isomer is the straight-chain tetrazene (NH2NNNH2). The results show that N4H4 isomers have high positive heats of formation (ΔHf298) and are highly energetic. The calculated ΔHf298 values are about 300–600 kJ/mol. If synthesized, they would be possible candidates of high-energy-density materials (HEMDs).

•Stabilization effect of applied electric field on activated structures was addressed.•Bond activation energy of FOX-7 decreases under electric fields in regardless of field direction.•Bond rupture path, homolytic or heterolytic, is affected by field direction and strength.•Field-induced peak splitting in stretching vibrations and redshift in electronic absorption were revealed.Molecular structure, vibrational and electronic absorption spectra, chemical reactivity of energetic compound FOX-7, one of the most widely used explosives, were studied computationally in presence of an electrostatic field of 0.01–0.05 a.u. The CN bond, which usually triggers the decomposition of FOX-7, is shortened/elongated under a parallel/antiparallel field. The CN bond activation energy varies with the external electric field, decreasing remarkably with the field strength in regardless of the field direction. This is attributed to two aspects: the bond weakening by the field parallel to the CN bond and the stabilization effect on the transition-state structure by the field antiparallel to the bond. The variations in the structure and property of FOX-7 under the electric fields were further analyzed with its distributional polarizability, which is dependent on the charge transfer characteristics through the CN bond.

Counterintuitive amine lone pair⋯π interactions are computationally revealed by MP2 and CCSD(T) methods, attractive lone pair⋯π interactions are observed when the lone pair of nitrogen points toward the π system. Symmetry adapted perturbation theory (SAPT) calculations and atoms in molecules (AIM) analyses were performed and the origin of the calculated attractive interaction between nitrogen lone pairs and π rings is discussed. Dispersion effects were revealed to play a crucial role in the attractive lone pair⋯π interaction.