Journal of Computational Chemistry

Cover image for Vol. 36 Issue 23

Early View (Online Version of Record published before inclusion in an issue)

Edited By: Charles L. Brooks III, Masahiro Ehara, Gernot Frenking, and Peter R. Schreiner

Impact Factor: 3.589

ISI Journal Citation Reports © Ranking: 2014: 36/157 (Chemistry Multidisciplinary)

Online ISSN: 1096-987X

Associated Title(s): International Journal of Quantum Chemistry, Wiley Interdisciplinary Reviews: Computational Molecular Science

VIEW

  1. 1 - 39
  1. Full Papers

    1. Transferability and additivity of dihedral parameters in polarizable and nonpolarizable empirical force fields

      Marie Zgarbová, Andreana M. Rosnik, F. Javier Luque, Carles Curutchet and Petr Jurečka

      Article first published online: 30 JUL 2015 | DOI: 10.1002/jcc.24012

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      Explicit inclusion of polarization in empirical force fields may improve transferability of dihedral angle parameters between molecules and different environments and also additivity of the dihedral terms in larger molecules. However, treatment of the short range polarization interactions between close neighbors, that is, the 1–2 and 1–3 interactions, seems to be crucial in achieving the desired effects.

    2. Comparison of radii sets, entropy, QM methods, and sampling on MM-PBSA, MM-GBSA, and QM/MM-GBSA ligand binding energies of F. tularensis enoyl-ACP reductase (FabI)

      Pin-Chih Su, Cheng-Chieh Tsai, Shahila Mehboob, Kirk E. Hevener and Michael E. Johnson

      Article first published online: 27 JUL 2015 | DOI: 10.1002/jcc.24011

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      Computation prediction on ligand-protein binding activities (Molecular Mechanics Poisson-Boltzmann surface area (MM-PBSA), (Quantum Mechanics/) MM-Generalized Born surface area ((QM/)MM-GBSA), has gained attention in the pharmaceutical community due to its efficiency and accuracy. However, the effect of radii sets, GB methods, QM Hamiltonians, sampling protocols, and simulation length on the MM-PBSA and (QM/)MM-GBSA performance has not been extensively studied. The article highlights the importance of these factors in the MM-PBSA and (QM/)MM-GBSA performance using the bacterial enoyl-ACP reductase and benzimidazole inhibitors as a test case.

    3. Bis(azulene) “submarine” metal dimer sandwich compounds (C10H8)2M2 (M = Ti, V, Cr, Mn, Fe, Co, Ni): Parallel and opposed orientations

      Hongyan Wang, Hui Wang, R. Bruce King and Henry F. Schaefer III

      Article first published online: 27 JUL 2015 | DOI: 10.1002/jcc.24013

      Thumbnail image of graphical abstract

      The lowest energy (C10H8)2M2 submarine sandwich structures of the early transition metals Ti, V, Cr, and Mn have the azulene units functioning as bis(pentahapto) ligands to each metal atom. For the later transition metals Fe, Co, and Ni the lowest energy (C10H8)2M2 structures contain pentahapto-trihapto azulene ligands with an uncomplexed C[DOUBLE BOND]C double bond

    4. A new QM/MM method oriented to the study of ionic liquids

      M. Luz Sánchez, José C. Corchado, M. Elena Martín, Ignacio Fdez. Galván, Rute Barata-Morgado and Manuel A. Aguilar

      Article first published online: 24 JUL 2015 | DOI: 10.1002/jcc.24023

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      A new quantum mechanic/molecular mechanic method, related to the average solvent electrostatic potential/molecular dynamics methodology, is presented to the study of pure ionic liquids. The method permits, through an iterative procedure, the full coupling between the polarized charge distribution of the ions and the liquid structure around them. The procedure has been tested with 1-ethyl-3-methylimidazolium tetrafluoroborate.

    5. A deeper insight into strain for the sila-bi[6]prismane ( Si18H12) cluster with its endohedrally trapped silicon atom, Si19H12

      Holger Vach, Lena V. Ivanova, Qadir K. Timerghazin, Fatme Jardali and Ha-Linh Thi Le

      Article first published online: 24 JUL 2015 | DOI: 10.1002/jcc.24009

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      Formation of overcoordinated silicon hydride nanoclusters with nontetrahedral atomic configurations is the result of a self-assembly process in a silane/hydrogen plasma reactor operated close to dusty plasma conditions as shown in our ab initio molecular dynamics simulations. Both symmetric and asymmetric Si19H12 isomers are ultrastable and exhibit aromatic-like behavior. Ultrastability results from extensive electron delocalization that is induced by electron-deficient bonds.

    6. Strain in nonclassical silicon hydrides: An insight into the “ultrastability” of sila-bi[6]prismane (Si18H12) cluster with the endohedrally trapped silicon atom, Si19H12

      Grygoriy A. Dolgonos and Koshka Mekalka

      Article first published online: 24 JUL 2015 | DOI: 10.1002/jcc.24014

      Thumbnail image of graphical abstract

      Formation of a tubular silicon hydride nanocluster bearing nontetrahedral atomic configurations requires significant amount of energy. As in the case of recently proposed tubular “ultrastable” sila-bi[6]prismane with one encaged silicon atom, Si19H12, the energy difference with respect to the tetrahedral reference molecules (called “strain energy”) is high enough to cause isomerization or fragmentation reactions. Consequently, this isomer cannot be considered as “ultrastable” nor as aromatic. Two new low-lying Si19H12 isomers have been proposed.

    7. Linear, planar, and tubular molecular structures constructed by double planar tetracoordinate carbon D2h C2(BeH)4 species via hydrogen-bridged [BOND]BeH2Be[BOND] bonds

      Xue-Feng Zhao, Haixia Li, Cai-Xia Yuan, Yan-Qin Li, Yan-Bo Wu and Zhi-Xiang Wang

      Article first published online: 22 JUL 2015 | DOI: 10.1002/jcc.24018

      Thumbnail image of graphical abstract

      D2h C2(BeH)4 has been computationally characterized to be a species featuring double planar tetracoordinate carbons. Because of the electron deficiency nature of the BeH bonds, the species can serves as building blocks to construct nano-size structures via the intermolecular hydrogen-bridged -BeH2Be- bonds (HBB), as exemplified by our reported molecular chains, planar sheets, and tubes. Formation of a HBB is exothermic by more than 30.0 kcal/mol, implying a possibility to synthesize these nano-size molecules.

    8. Understanding the basis of I50V-induced affinity decrease in HIV-1 protease via molecular dynamics simulations using polarized force field

      Rui Duan, Raudah Lazim and Dawei Zhang

      Article first published online: 22 JUL 2015 | DOI: 10.1002/jcc.24020

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      Polarization effects play a crucial role in the precise depiction of proteins in molecular dynamics (MD) simulations. In this study, MD simulations using a polarized force field were used to examine the effect of I50V mutation on the binding affinities of inhibitors to HIV-1 protease. The polarization effect was introduced using a polarized protein-specific charge scheme. The charges of complexes were derived using a newly proposed delta-RESP method to overcome the poorly determined charges of buried atoms. The calculated variations in mutation-induced affinities agreed well with the experiment.

  2. Software News and Updates

    1. AquaBridge: A novel method for systematic search of structural water molecules within the protein active sites

      Arina Afanasyeva, Sergey Izmailov, Michel Grigoriev and Michael Petukhov

      Article first published online: 22 JUL 2015 | DOI: 10.1002/jcc.24022

      Thumbnail image of graphical abstract

      AquaBridge is a tool for seeking structural water molecules within protein binding pockets, developed as a module for the ICM-Pro software package for molecular modeling. This utility is based on Monte-Carlo energy minimization algorithms and selects the water molecule conformations that can form “water bridges” by calculating the values of the total energy of a modeled water molecule and of the number of hydrogen bonds that it can form between the target protein and the ligand.

  3. Full Papers

    1. Hirshfeld-based intrinsic polarizability density representations as a tool to analyze molecular polarizability

      Nicolás Otero, Christian Van Alsenoy, Claude Pouchan and Panaghiotis Karamanis

      Article first published online: 21 JUL 2015 | DOI: 10.1002/jcc.24003

      Thumbnail image of graphical abstract

      The electric-dipole polarizability in molecules provides information about optical properties, long-range interactions and chemical reactivity. Accordingly, we propose a new procedure to obtain total atom-in-molecule polarizability representations and its volume-independent component by means of a Hirshfeld-based atomic partitioning. These easy-to-interpret representations give which atoms or regions are more polarizable in a molecule and definitely extend the polarizability as a tool for electron delocalization studies in polycyclic aromatic hydrocarbons like the supertriangulene shown here.

    2. Projected CAP/SAC-CI method with smooth Voronoi potential for calculating resonance states

      Masahiro Ehara, Ryoichi Fukuda and Thomas Sommerfeld

      Article first published online: 21 JUL 2015 | DOI: 10.1002/jcc.24010

      Thumbnail image of graphical abstract

      The complex absorbing potential (CAP)/symmetry-adapted cluster-configuration interaction method with a smooth Voronoi potential (example shown in the inset of the figure) has been developed. The method is applied to the π* resonance states of small- to medium-size molecules with double-bond and heteroaromatic structures. The corrected η-trajectory provides a stable resonance energy and width for all the resonances studied. Generally, the stabilization of the trajectories is clearer for the CAPs with relatively large cavity size.

    3. Ab initio/GIAO-CCSD(T) 13C NMR study of the rearrangement and dynamic aspects of rapidly equilibrating tertiary carbocations, C6 H13+ and C7 H15+

      George A. Olah, G. K. Surya Prakash and Golam Rasul

      Article first published online: 20 JUL 2015 | DOI: 10.1002/jcc.24019

      Thumbnail image of graphical abstract

      The rearrangement pathways of the equilibrating tertiary carbocations such as 2,3-dimethyl-2-butyl cation were calculated by the ab initio/GIAO-CCSD(T) method.

  4. Erratum

    1. You have free access to this content
      Theoretical analysis of excited states and energy transfer mechanism in conjugated dendrimers

      Jing Huang, Likai Du, Deping Hu and Zhenggang Lan*

      Article first published online: 17 JUL 2015 | DOI: 10.1002/jcc.24005

      This article corrects:

      Theoretical analysis of excited states and energy transfer mechanism in conjugated dendrimers

      Vol. 36, Issue 3, 151–163, Article first published online: 21 NOV 2014

  5. Full Papers

    1. Molybdatricarbaboranes as examples of isocloso metallaborane deltahedra with three carbon vertices

      Alexandru Lupan and R. Bruce King

      Article first published online: 16 JUL 2015 | DOI: 10.1002/jcc.23995

      Thumbnail image of graphical abstract

      The lowest energy CpMoC3Bn−4Hn−1 (n = 8, 9, 10, 11) structures are based on isocloso or similar MoC3Bn−4 deltahedra with the molybdenum atom at the unique degree 6 vertex, the carbon atoms at the lowest degree vertices (typically degree 4 vertices), no pairs of adjacent carbon atoms (i.e., no C-C edges), and the maximum number of Mo-C edges.

    2. Self-guided Langevin dynamics via generalized Langevin equation

      Xiongwu Wu, Bernard R. Brooks and Eric Vanden-Eijnden

      Article first published online: 16 JUL 2015 | DOI: 10.1002/jcc.24015

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      Self-guided Langevin dynamics (SGLD) is a molecular simulation method that enhances conformational search and sampling via acceleration of the low frequency motions of the molecular system. To eliminate the need of reweighting, the SGLD-generalized Langevin equation (GLE) method is proposed, which samples exact ensemble distribution and has enhanced conformational sampling. Using an alanine dipeptide and liquid argon, SGLD-GLE can produce correct NVT and NPT ensemble distributions while achieving enhanced conformational sampling.

    3. Contrasting electronic requirements for C[BOND]H binding and C[BOND]H activation in d6 half-sandwich complexes of rhenium and tungsten

      Murugesan Thenraj and Ashoka G. Samuelson

      Article first published online: 15 JUL 2015 | DOI: 10.1002/jcc.24002

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      A computational study of the interaction of alkanes with d6-half-sandwich metal fragments having Re or W is presented. Different ligands like linear nitrosyl (NO+), carbon monoxide, trifluorophosphine, N-heterocyclic carbene (NHC), show that electron deficient NO+ favors alkane binding and electron donating NHC favors oxidative addition. Energy decomposition analysis shows that orbital interaction involving charge transfer from the alkane to the metal is key to stabilizing alkane binding.

    4. Algorithms for GPU-based molecular dynamics simulations of complex fluids: Applications to water, mixtures, and liquid crystals

      Sergey Kazachenko, Mark Giovinazzo, Kyle Wm. Hall and Natalie M. Cann

      Article first published online: 15 JUL 2015 | DOI: 10.1002/jcc.24000

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      Graphics Processing Units (GPUs) are the subject of considerable recent attention. Molecular dynamics simulations are particularly amenable to GPU-based computation as the necessary calculations can be easily parallelized. Our simulation code has been redesigned to run on multiple GPUs with algorithms for Gay-Berne interactions, Ewald summations, pair distributions, and neighbor lists. Results are presented for three test systems, including a liquid crystal, with computations on one to three GPUs on systems that contain up to 196,608 sites.

    5. Noncatalytic bromination of benzene: A combined computational and experimental study

      Andrey V. Shernyukov, Alexander M. Genaev, George E. Salnikov, Henry S. Rzepa and Vyacheslav G. Shubin

      Article first published online: 14 JUL 2015 | DOI: 10.1002/jcc.23985

      Thumbnail image of graphical abstract

      The noncatalytic bromination of benzene is shown experimentally to require high concentrations of bromine, proceeding at ambient temperatures to form predominantly bromobenzene and exhibiting a measured inverse deuterium isotope effect. Computed transition states models reveal an ionic concerted but asynchronous transition state involving a Br7 or Br9 cluster which acts as a Br+ donor, as a proton base and as a stabilizing arm forming weak dispersion interactions with benzene C[BOND]H hydrogens.

    6. Effect of methylation on relative energies of tautomers and on the intramolecular proton transfer barriers of protonated nitrosamine: A MR-CISD study

      Railton Barbosa de Andrade, Ezequiel Fragoso Vieira Leitão, Miguel Angelo Fonseca de Souza, Elizete Ventura and Silmar Andrade do Monte

      Article first published online: 14 JUL 2015 | DOI: 10.1002/jcc.24007

      Thumbnail image of graphical abstract

      Nitrosamines have three protonation sites. The barrier heights associated with the proton transfer among these sites on protonated nitrosamine and N,N-dimethylnitrosamine were studied by highly correlated electronic structure calculations. Methylation of nitrosamine impacted significantly the relative energies of both the species protonated on the amine nitrogen atom and that of the transition state associate with proton transfer between the amine nitrogen and oxygen atoms.

    7. Aqueous acidities of primary benzenesulfonamides: Quantum chemical predictions based on density functional theory and SMD

      Kęstutis Aidas, Kiril Lanevskij, Rytis Kubilius, Liutauras Juška, Daumantas Petkevičius and Pranas Japertas

      Article first published online: 7 JUL 2015 | DOI: 10.1002/jcc.23998

      Thumbnail image of graphical abstract

      Aqueous acidities of a family of primary benzenesulfonamides were computed using density functional theory and SMD model. The predicted inline image values compare to experimental data very well when a proton exchange thermodynamic cycle is used. It was found necessary to perform geometry optimization of neutral and deprotonated species in vacuum and solution separately as different conformations are stabilized in these two phases.

    8. Adsorption-induced changes of intramolecular optical transitions: PTCDA/NaCl and PTCDA/KCl

      Manuel Hochheim and Thomas Bredow

      Article first published online: 7 JUL 2015 | DOI: 10.1002/jcc.23990

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      A precise and cost-efficient methodology based on time-dependent density functional theory is presented for the investigation of the optical properties of π-conjugated organic molecules adsorbed on ionic surfaces.

    9. A theoretical study of imine hydrocyanation catalyzed by halogen-bonding

      Norah Heinz, Michael Dolg and Albrecht Berkessel

      Article first published online: 7 JUL 2015 | DOI: 10.1002/jcc.23999

      Thumbnail image of graphical abstract

      A mechanistic description of an organocatalysis based on halogen-bonding: Possible reaction pathways of the hydrocyanation of an imine species catalyzed by C[DOUBLE BOND]N activation by four different monodentate halogen-bond donors. The mechanism is evaluated and discussed in detail at the level of scalar-relativistic gradient-corrected density functional theory.

  6. Full PaperS

    1. Atomic-resolution dissection of the energetics and mechanism of isomerization of hydrated ATP-Mg2+ through the SOMA string method

      Davide Branduardi, Fabrizio Marinelli and José D. Faraldo-Gómez

      Article first published online: 7 JUL 2015 | DOI: 10.1002/jcc.23991

      Thumbnail image of graphical abstract

      The mechanisms of isomerization of ATP-Mg2+ in solution are examined with three complementary enhanced-sampling simulation methods. The recently developed String Method with Optimal Molecular Alignment is used to identify and characterize the minimum free-energy paths for the major conformational transitions of the complex, in a 48-dimensional space. This analysis reveals the driving forces controlling these isomerization mechanisms at single-atom resolution.

  7. Full Papers

    1. Structure and stability of noble gas bound EX3+ compounds (E = C, Ge, Sn, Pb; X = H, F, Cl, Br)

      Sudip Pan, Diego Moreno, Sreyan Ghosh, Pratim K. Chattaraj and Gabriel Merino

      Article first published online: 1 JUL 2015 | DOI: 10.1002/jcc.23986

      Thumbnail image of graphical abstract

      Making a bond: inline image (E = C-Pb; X = H, F-Br) could bind noble gas atoms, particularly Ar to Rn, quite effectively. The π back-bonding causing X [RIGHTWARDS ARROW] E electron transfer plays an important role in deciding their noble gas binding ability.

    2. On the inclusion of post-MP2 contributions to double-Hybrid density functionals

      Bun Chan, Lars Goerigk and Leo Radom

      Article first published online: 1 JUL 2015 | DOI: 10.1002/jcc.23972

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      Double-hybrid density functionals (DHDFs) use MP2-type correlation to significantly improve the accuracy of DFT approximations. The inclusion of higher-order MP3, MP4, CCSD, and CCSD(T) terms is explored. DHDFs are not as systematically improvable as their wave-function counterparts, and the use of MP2 represents a near-optimal balance of accuracy and efficiency. These findings provide valuable insights for future research in DHDF development.

    3. Comparative exploration of hydrogen sulfide and water transmembrane free energy surfaces via orthogonal space tempering free energy sampling

      Chao Lv, Erick W. Aitchison, Dongsheng Wu, Lianqing Zheng, Xiaolin Cheng and Wei Yang

      Article first published online: 29 JUN 2015 | DOI: 10.1002/jcc.23982

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      The orthogonal space tempering simulation shows that hydrogen sulfide is amphipathic, and thus is favorably localized at the interface between the head-group and acyl chain regions. Because the membrane binding affinity of H2S is mainly governed by its small hydrophobic moiety and the barrier height inbetween the interfacial region and the membrane center is largely determined by its moderate polarity, the trans-membrane free energy barriers to encounter by this toxic molecule are very small.

    4. Hydrogen bond–aromaticity cooperativity in self-assembling 4-pyridone chains

      Megha Anand, Israel Fernández, Henry F. Schaefer III and Judy I-Chia Wu

      Article first published online: 23 JUN 2015 | DOI: 10.1002/jcc.23976

      Thumbnail image of graphical abstract

      Hydrogen bonding interactions can polarize the π-systems of 4-pyridones to increase cyclic (4n+2) π electron delocalization. The resulting H-bonded six-membered rings exhibit enhanced π-aromaticity and the corresponding N[BOND]H···O[DOUBLE BOND]C interactions are strengthened. Extended H-bonded 4-pyridone chains exhibit high degrees of such cooperativity, even when each of the neighboring 4-pyridone rings are twisted to preclude direct π-overlap between the H-bonded units.

    5. Saturn Systems

      Habib U. Rehman, Nida A. McKee and Michael L. McKee

      Article first published online: 19 JUN 2015 | DOI: 10.1002/jcc.23979

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      Nanohoops, such as cycloparaphenylenes [10]CPP, can bind to C60 and [Li@C60)]+ through noncovalent interactions with free energies of binding greater than 10 kcal/mol in nonpolar solvents. With the right size, the hoops bind around the equator of the fullerene and resemble the ring around Saturn. Density functional calculations can predict the binding constants and suggest new nanohoops as targets for synthesis. The graphic image is the HOMO of C60@(C6H4)10.

    6. Accurately modeling nanosecond protein dynamics requires at least microseconds of simulation

      Gregory R. Bowman

      Article first published online: 16 JUN 2015 | DOI: 10.1002/jcc.23973

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      This article assesses whether modern simulations accurately capture ps-ns timescales—as judged by their ability to predict order parameters—or if force fields are now a limiting factor. The results show microseconds of simulation with any of three force fields and a proper method for calculating order parameters are required for accuracy and precision. This has important implications for the extent of simulations required for slower processes and the utility of enhanced sampling methods.

    7. Heats of formation of platonic hydrocarbon cages by means of high-level thermochemical procedures

      Amir Karton, Peter R. Schreiner and Jan M. L. Martin

      Article first published online: 12 JUN 2015 | DOI: 10.1002/jcc.23963

      Thumbnail image of graphical abstract

      This work determines total atomization energies and heats of formation for platonic and prismatic polycyclic hydrocarbon cages by means of the W1-F12 and W2-F12 thermochemical protocols. Using these accurate reference data, the performance of computationally economical theoretical methods (e.g., density functional theory and composite ab initio methods) was evaluated via atomization and bond separation reactions for the calculation of these challenging thermochemical quantities.

    8. Nucleus-independent chemical shift analysis of the electronic states of the (CO)4, (CS)4, and (CSe)4 molecules

      Yunfei Zhou, Xiaoguang Bao and Weston Thatcher Borden

      Article first published online: 8 JUN 2015 | DOI: 10.1002/jcc.23962

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      The occupancy of the a2u MOs of (CO)4, (CS)4, and (CSe)4 control the NICS(1) values that are computed for these compounds.

    9. Multiscale enhanced sampling of intrinsically disordered protein conformations

      Kuo Hao Lee and Jianhan Chen

      Article first published online: 6 JUN 2015 | DOI: 10.1002/jcc.23957

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      Multiscale enhanced sampling (MSES) uses efficient coarse-grained (CG) models to accelerate sampling of atomistic protein conformations. The efficacy of MSES for simulating intrinsically disordered proteins (IDPs) is investigated, and refined MSES Hamiltonian/temperature replica exchange protocols are developed that involve additional parameters in the MSES coupling restraint potential. The refined protocols drive more conformational transitions to improve the convergence of simulated ensembles. Nonetheless, further improvement of MSES for simulating IDPs likely requires more detailed CG models.

    10. The Reaction between Bromine and the Water Dimer and the Highly Exothermic Reverse Reaction

      Guoliang Li, Hui Wang, Qian-Shu Li, Yaoming Xie and Henry F. Schaefer III

      Article first published online: 4 JUN 2015 | DOI: 10.1002/jcc.23951

      Thumbnail image of graphical abstract

      The entrance complex, transition state, and exit complex for the Br + (H2O)2 [RIGHTWARDS ARROW] HBr + (H2O)OH reaction have been investigated using the CCSD(T) method with correlation consistent basis sets up to cc-pVQZ-PP. Both zero-point vibrational energies and spin-orbit coupling effects are found to be important. The potential energy surface for the Br + (H2O)2 reaction is compared with the related Br + H2O, Cl + (H2O)2 and F + (H2O)2 reactions.

    11. The origins of the directionality of noncovalent intermolecular interactions#

      Changwei Wang, Liangyu Guan, David Danovich, Sason Shaik and Yirong Mo

      Article first published online: 25 MAY 2015 | DOI: 10.1002/jcc.23946

      Thumbnail image of graphical abstract

      The block-localized wavefunction method, which can derive hypothetical structures without the charge transfer effect and conduct intermolecular energy decomposition analysis, is used to probe the origins of the directionality of weak noncovalent bonds. While the overall steric energy exhibits certain angular dependency, in all cases the charge transfer exhibits the strongest directionality, suggesting that the linearity or near linearity of noncovalent bonds is largely governed by the charge-transfer interaction whose magnitude determines the bond covalency.

    12. A comparative computationally study about the defined m(II) pincer hydrogenation catalysts (m = fe, ru, os)

      Haijun Jiao, Kathrin Junge, Elisabetta Alberico and Matthias Beller

      Article first published online: 17 MAY 2015 | DOI: 10.1002/jcc.23944

      Thumbnail image of graphical abstract

      DFT studies on the defined pincer-type catalysts M(H)2(CO)[NH(C2H4PiPr2)2] (1M) and M(H)(CO)[N(C2H4PiPr2)2] (2M) (M = Fe, Ru, Os) reveal remarkable differences in electronic structures and hydrogenation reactivity of nitriles, ester, and ketones. For acetonitrile hydrogenation, Fe- and Ru-based catalysts are best. For methyl benzoate hydrogenation and dehydrogenation of benzyl alcohol, Ru-based catalysts are best. In contrast, Os-based catalysts are least active.

    13. Inter- and intramolecular CF···c[DOUBLE BOND]o interactions on aliphatic and cyclohexane carbonyl derivatives

      Rodrigo A. Cormanich, Roberto Rittner, David O'Hagan and Michael Bühl

      Article first published online: 23 APR 2015 | DOI: 10.1002/jcc.23918

      Thumbnail image of graphical abstract

      Prototypical inter- and intramolecular CF···C[DOUBLE BOND]O interactions are assessed computationally at the B3LYP-D3 level. The interactions are noticeable in intermolecular complexes 1, where they can amount to stabilizations around about 1 kcal mol, however, they are not strong enough to dominate conformational preferences in organofluorine derivatives such as 2 - 4.

    14. Theoretical and experimental investigation of crown/ammonium complexes in solution

      Andreas J. Achazi, Larissa K. S. von Krbek, Christoph A. Schalley and Beate Paulus

      Article first published online: 13 APR 2015 | DOI: 10.1002/jcc.23914

      Thumbnail image of graphical abstract

      Gibbs energies of association inline image of monovalent crown/ammonium complexes in solution are calculated with DFT-D3(BJ) and the continuum solvation model COSMO-RS. For comparison, experimental data are obtained by isothermal titration calorimetry. Calculated and measured Gibbs energies of association inline image in solution agree well.

    15. From small fullerenes to the graphene limit: A harmonic force-field method for fullerenes and a comparison to density functional calculations for Goldberg–Coxeter fullerenes up to C980

      Lukas N. Wirz, Ralf Tonner, Andreas Hermann, Rebecca Sure and Peter Schwerdtfeger

      Article first published online: 26 MAR 2015 | DOI: 10.1002/jcc.23894

      Thumbnail image of graphical abstract

      A general force field is introduced which works for all fullerene isomers. It leads to structures and zero-point vibrational energy contributions in very good agreement to more expensive quantum theoretical calculations. The graphene limit is well represented by the growth of Goldberg-Coxeter transforms of C20.

    16. Prediction of the crystal packing of di-tetrazine-tetroxide (DTTO) energetic material

      Jose L. Mendoza-Cortes, Qi An, William A. Goddard III, Caichao Ye and Sergey Zybin

      Article first published online: 18 MAR 2015 | DOI: 10.1002/jcc.23893

      Thumbnail image of graphical abstract

      The two most stable isomers of Di-tetrazine-tetroxide (DTTO), c1 and c2, were used to predict the most stable polymorphs of DTTO. For the c1 isomer, the most stable polymorph has P212121 space group with a density of 1.96 g/cm3. Conversely, for the c2 isomer, the most stable polymorph has Pbca space group with a density of 1.98 g/cm3. These predicted densities are among the highest of current energetic materials.

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