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In order to provide atomistic details for the mechanism of the collisional dynamics of O(3P) and dimethylamine (DMA) in the triplet electronic surface, direct dynamics simulations are reported herein. The simulations are performed at the U‐HSE06/aug‐cc‐pVDZ level of theory. The results are reported for the relative collision energy of 7.8 kcal/mol. For the vibrational and rotational excitations, following temperature regimes have been considered: 200 and 10 K, respectively. Simulations reveal that the reaction can lead to two product channels in the considered energy regime: (1) 2OH + 2CH3NHCH2 and (2) 2OH + 2CH3NCH3. The computed reaction cross section for pathways 1 and 2 are as follows: 17.89 ± 0.20 Å2 and 3.28 ± 0.03 Å2, whereas the computed microcanonical reaction rate constants for pathways 1 and 2 are as follows: (4.21 ± 0.05)*10−10 and (7.72 ± 0.07)*10−11 cm3/(molecule sec). Both pathways follow direct and indirect H abstraction processes. Among the direct pathways, stripping and rebound mechanisms have been observed, whereas the indirect pathway involves formation of a post‐reaction complex having lifetime ~0.4–0.5 ps. The velocity scattering angle distribution for the reaction is dominated by scattering in the sideways (60–120 °) and backward (120–180 °) directions with some contribution from the scattering in the forward direction (0–60 °). [ABSTRACT FROM AUTHOR]

The viability of sequestering gas molecules (CO, NO, CO2, NO2, N2O, O2, O3, H2O, NH3, H2, CH3OH, CH3F, C2H5F, C2H2, C2H4, HCN, and SO2) on the Al12Be cluster is investigated by carrying out density functional theory based computations. Thermochemical as well as energetic considerations suggest that Al12Be cluster adsorbs the chosen gas molecules in a favorable fashion. The gas molecules attain an activated state on getting adsorbed on the metal cluster as vindicated by Atoms‐in‐Molecule analysis. The possibility of CO oxidation, dissociative addition of CH3F and C2H5F, NH bond decomposition in NH3, dissociation of NO, and hydrogenation of C2H2 reactions on Al12Be cluster has been investigated. Results indicate that all the reactions take place in a thermodynamically favorable way at 298.15 K and one atmospheric pressure. The first five reactions aforementioned are kinetically favorable also and therefore are amenable to ambient temperature and pressure conditions. © 2017 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

The effect of geometrical confinement on the Diels-Alder reactions between some model dienes viz. furan, thiophene, cyclopentadiene, benzene, and a classic dienophile, ethylene has been explored by performing density functional theory-based calculations. The effect of confinement has been imposed by a rigid macrocyclic molecule cucurbit[7]uril (CB[7]). Results indicate that all the reactions become thermodynamically more favorable at 298.15 K temperature and one atmospheric pressure inside CB[7] as compared to the corresponding free gaseous state reactions. Moreover, the rate constants associated with the reactions experience manifold enhancement inside CB[7] as compared to the 'unconfined' reactions. Suitable contribution from the entropy factor makes the concerned reactions more facile inside CB[7]. The energy gap between the frontier molecular orbitals of the dienes and dienophiles decrease inside CB[7] as compared to that in the free state reactions thereby allowing facile orbital interactions. The nature of interaction as well as bonding has been analyzed with the help of atoms-in-molecules, noncovalent interaction, natural bond orbital as well as energy decomposition analyses. Results suggest that all the guests bind with CB[7] in an attractive fashion. Primarily, noncovalent interactions stabilize the host-guest systems. © 2017 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

The nature of host-guest interaction in between octa acid cavitand (OA) and some representative cationic guests (Li+, Na+, K+, Be+2, Mg+2, Ca+2, Li3O+, Na3O+, K3O+) as well as heterocyclic moieties like [adenine (A), guanine (G), cytosine (C), thymine (T), uracil (U), and tetrathiafulvalene (TTF)] has been examined with the aid of density functional theory (DFT)-based computations. Thermochemical results indicate that all the guests bind with OA in a thermodynamically favorable fashion at 298.15 K temperature and one atmospheric pressure. OA exhibits high selectivity in binding the lighter cations/metal cluster cations as compared to the heavier congeners along each given series. Moreover, OA exhibits enhanced affinity as well as selectivity in binding A/G/TTF molecules as compared to C/T/U. Noncovalent interaction and energy decomposition analyses reveal that in addition to the van der Waals interaction, significant contribution from electrostatic as well as orbital interactions dictate the outcome in all the host-guest complexes. Time dependent DFT calculations have been carried out to assess the role of the guests in tuning the electronic properties as well as absorption spectrum of OA. © 2017 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

The impact of functionalization as well as guest encapsulation on the optoelectronic properties of the ExBox+4 moiety has been investigated with the aid of density functional theory (DFT) based calculations. To this end, three functionalized variants of the ExBox+4 moiety have been modelled in silico, viz. NH2-ExBox+4-F, CN-ExBox+4-NH2 and NO2-ExBox+4-NH2, whereas coronene (Cor), B-doped coronene (BCor), N-doped coronene (NCor), tetrathiafulvalene (TTF), biphenyl (BiPh), tetracyanoethylene (TCNE) and tetracyanoquinodimethane (TCNQ) molecules have been employed as guests. The results indicate that as a result of functionalization, the ExBox+4 moiety can exhibit tangible non-linear optical (NLO) response properties as vindicated by the first static hyperpolarizability (β). As a result of guest encapsulation, significant variation in the optoelectronic properties of the chosen hosts takes place. BCor/TCNQ/NCor molecules enhance the NLO activity of the hosts while TTF/TCNE suppresses the same. In particular, NCor@host moieties demonstrate very high β values at the static field limit. Time dependent DFT results suggest that in general, the ability of the guest in tuning the transition energy associated with the pivotal electronic transitions of the host plays the dominant role in the observed variation in β. In addition, BCor/NCor@host moieties demonstrate broadband optical absorption capability thereby elucidating the possibility of deriving multi-purpose optoelectronic features such as NLO activity as well as utility in photovoltaic systems. Thermochemical results suggest that all the guest@host systems are stable at 298.15 K. Non-covalent and electrostatic binding forces stabilize the studied systems. [ABSTRACT FROM AUTHOR]

The possibility of having neutralXe-bound compounds mediated bysome representative transition metal fluorides of general formulaMX3(where M=Ru, Os, Rh, Ir, Pd, Pt, Ag, Au and X=F) hasbeen investigated through density functional theory based calculations.Nature of interaction between MX3and Xe moieties has beencharacterized through detailed electron density, charge density andbond energy decomposition analyses. The feasibility of having compoundsof general formula XeMX3at 298 K has been predicted throughthermodynamic considerations. The nature of interaction in betweenXe and M atoms is partly covalent in nature and the orbital interactionis the dominant contributor toward these interactions as suggestedby energy decomposition analysis. [ABSTRACT FROM AUTHOR]

The viability of sequestering gas molecules (CO, NO, CO 2 , NO 2 , N 2 O, O 2 , O 3 , H 2 O, NH 3 , H 2 , CH 3 OH, CH 3 F, C 2 H 5 F, C 2 H 2 , C 2 H 4 , HCN, and SO 2 ) on the Al 12 Be cluster is investigated by carrying out density functional theory based computations. Thermochemical as well as energetic considerations suggest that Al 12 Be cluster adsorbs the chosen gas molecules in a favorable fashion. The gas molecules attain an activated state on getting adsorbed on the metal cluster as vindicated by Atoms-in-Molecule analysis. The possibility of CO oxidation, dissociative addition of CH 3 F and C 2 H 5 F, NH bond decomposition in NH 3 , dissociation of NO, and hydrogenation of C 2 H 2 reactions on Al 12 Be cluster has been investigated. Results indicate that all the reactions take place in a thermodynamically favorable way at 298.15 K and one atmospheric pressure. The first five reactions aforementioned are kinetically favorable also and therefore are amenable to ambient temperature and pressure conditions. © 2017 Wiley Periodicals, Inc., (© 2017 Wiley Periodicals, Inc.)

The impact of functionalization as well as guest encapsulation on the optoelectronic properties of the ExBox +4 moiety has been investigated with the aid of density functional theory (DFT) based calculations. To this end, three functionalized variants of the ExBox +4 moiety have been modelled in silico, viz. NH 2 -ExBox +4 -F, CN-ExBox +4 -NH 2 and NO 2 -ExBox +4 -NH 2 , whereas coronene (Cor), B-doped coronene (BCor), N-doped coronene (NCor), tetrathiafulvalene (TTF), biphenyl (BiPh), tetracyanoethylene (TCNE) and tetracyanoquinodimethane (TCNQ) molecules have been employed as guests. The results indicate that as a result of functionalization, the ExBox +4 moiety can exhibit tangible non-linear optical (NLO) response properties as vindicated by the first static hyperpolarizability (β). As a result of guest encapsulation, significant variation in the optoelectronic properties of the chosen hosts takes place. BCor/TCNQ/NCor molecules enhance the NLO activity of the hosts while TTF/TCNE suppresses the same. In particular, NCor@host moieties demonstrate very high β values at the static field limit. Time dependent DFT results suggest that in general, the ability of the guest in tuning the transition energy associated with the pivotal electronic transitions of the host plays the dominant role in the observed variation in β. In addition, BCor/NCor@host moieties demonstrate broadband optical absorption capability thereby elucidating the possibility of deriving multi-purpose optoelectronic features such as NLO activity as well as utility in photovoltaic systems. Thermochemical results suggest that all the guest@host systems are stable at 298.15 K. Non-covalent and electrostatic binding forces stabilize the studied systems.

The impact of geometrical confinement on the thermodynamic as well as kinetic aspects of a model cycloaddition reaction between 1,3-butadiene and ethylene have been investigated based on density functional theory calculations. To this end, organic hosts ExBox +4 and cucurbit[7]uril (CB[7]) were used to impose confinement effects on the reactants, transition state (TS), and product involved in the reaction. The results suggest that the shape of the host and thereby the nature of the confining regime dictates the thermodynamic outcome of the reaction. The reaction becomes thermodynamically more spontaneous inside CB[7] as compared with that in either ExBox +4 or in the "unconfined" gaseous state. Furthermore, the rate constant associated with the reaction increases manifold inside CB[7]. Atoms-in a-molecule, noncovalent interaction, natural bond orbital, as well as energy decomposition analyses suggest that the close geometrical proximity of the reactants inside CB[7] as well as extra stabilization of the TS in the encapsulated state may dictate the outcome., (© 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)