Univesité Pierre et Marie CURIE Topological Approaches to Intermolecular Interactionshttp://video.upmc.fr//differe.php?collec=S_topological_approaches_2013Workshop on "Topological approaches to intermolecular interactions"http://vodcast.upmc.fr/images/Co13_topological_approaches.jpgTopological Approaches to Intermolecular Interactionshttp://video.upmc.fr//differe.php?collec=S_topological_approaches_2013S. J. Grabowski: Non-covalent interactions: characteristics and mechanisms of formation - the topological approachhttp://video.upmc.fr//differe.php?collec=S_topological_approaches_2013&video=8Numerous non-covalent interactions are characterized by the electron charge transfer from the Lewis base unit to the Lewis acid [1]. This is connected with the other processes reflected by the change of geometrical, energetic and topological parameters. For example, different characteristics of the hydrogen bond and various criteria of the existence of this interaction were discussed in the literature [2]. One can mention the topological criteria of Koch and Popelier [3,4]. On the other hand, the hydrogen bond mechanism was discussed in terms of NBO method [5]. Very recently it was found that the hydrogen bond, the halogen bond and other non-covalent interactions are steered by the same processes [6]. This is reflected by the same changes of parameters. For example, the A-H...B hydrogen bond formation is connected with the increase of the positive charge of H-atom and the decrease of its volume. The same changes are observed for X-halogen atom in the A-X...B halogen bond. Various similarities and differences between numerous non-covalent interactions may be discussed.<br /> <br /> [1] Lipkowski, P.; Grabowski, S. J.; Leszczynski, J. J. Phys. Chem. A 2006, 110, 10296–10302.<br /> [2] Grabowski, S.J. Chem.Rev. 2011, 11, 2597-2625.<br /> [3] Koch, U.; Popelier, P.L.A. J.Phys.Chem. 1995, 99, 9747-9754.<br /> [4] Popelier, P. Atoms in Molecules. An Introduction, Prentice Hall, Pearson Education Limited 2000.<br /> [5] Alabugin, I.V.; Manoharan, M.; Peabody, S.; Weinhold, F. J.Am.Chem.Soc. 2003, 125, 5973-5987.<br /> [6] Grabowski, S.J. Phys.Chem.Chem.Phys. accepted Fri, 27 Sep 2013 14:15:54 +0200S_topological_approaches_2013_8W. Yang: Non-Covalent Interaction Analysis in Fluctuating Environments and Exchange-Correlation Energies from Response Propertieshttp://video.upmc.fr//differe.php?collec=S_topological_approaches_2013&video=7To apply the NCI analysis to fluctuating environments as in solution phase, we developed a new Averaged NonCovalent Interaction (i.e., aNCI) index along with a fluctuation index to characterize magnitude of interactions and fluctuations. We applied aNCI for various systems including solute-solvent and ligand-protein noncovalent interactions. For water and benzene molecules in aqueous solution, solvation structures and the specific hydrogen bond patterns were visualized clearly. For the Cl-+CH3Cl SN2 reaction in aqueous solution, charge reorganization influences over solvation structure along SN2 reaction were revealed. For ligand-protein systems, aNCI can recover several key fluctuating hydrogen bond patterns that have potential applications for drug design. Therefore, aNCI, as a complementary approach to the original NCI method, can extract and visualize noncovalent interactions from thermal noise in fluctuating environments.<br /> <br /> In the second part of the talk, we will present an adiabatic connection to formulate the exchange-correlation energy in terms of response properties. This formulation of the exchange-correlation energy opens new channels for density functional approximations based on the many-body perturbation theory. We illustrate the potential of such approaches with an approximation based on the Random Phase Approximation. This resulting method has many highly desirable properties. It has minimal delocalization error with a nearly linear energy behavior for systems with fractional charges, describes van der Waals interactions similarly and thermodynamic properties significantly better than the conventional RPA, and eliminates static correlation error for single bond systems. Most significantly, it is the first known functional with an explicit and closed-form dependence on the occupied and unoccupied orbitals that captures the energy derivative discontinuity in strongly correlated systems. Fri, 27 Sep 2013 14:15:53 +0200S_topological_approaches_2013_7P. Popelier: Quantum Chemical Topology: on Bonds and Force Fieldshttp://video.upmc.fr//differe.php?collec=S_topological_approaches_2013&video=9Quantum Chemical Topology (QCT)[1,2] is an umbrella method that includes QTAIM[3,4] as a special case. The central idea of QCT is to partition through a gradient vector field, and apply the language and insights of dynamical systems. This talk has two distinct parts (that could be unified in future work).<br /> <br /> The first part[5] discusses how to draw a molecule from a molecular wave function. The spatial distribution of atoms in a molecule in the form of chemical graphs is obtained for a set of molecules, using their corresponding domain-averaged exchange-correlation energies (Vxc). Conveniently, such energies are transferable (for 1,n interactions in saturated linear hydrocarbons) and can provide an accurate estimation of the covalent-like contribution between pairs of given interacting topological atoms A and B.<br /> <br /> The second part focuses on the electrostatic interaction in a novel topological force field for biomolecular modeling. Topological atoms are boxes with a particular shape and a finite volume. If the coordinates change then the shapes of the atoms change too, as well as their multipole moments. This complex relationship is captured by a machine learning technique called kriging. Here I will explore how these ideas6 can be used to enhance the realism of the electrostatic energy, [7,8] and put polarisation and charge transfer on the same footing, without having a polarisation catastrophe.<br /> <br /> [1] Popelier, P. L. A.; Brémond, É. A. G. Int.J.Quant.Chem. 2009, 109, 2542.<br /> [2] Popelier, P. L. A. In Structure and Bonding. Intermolecular Forces and Clusters, Ed, D.J.Wales; Springer: Heidelberg, Germany, 2005; Vol. 115, p 1.<br /> [3] Bader, R. F. W. Atoms in Molecules. A Quantum Theory.; Oxford Univ. Press, Great Britain, 1990.<br /> [4] Popelier, P. L. A. Atoms in Molecules. An Introduction.; Pearson Education: London, Great Britain, 2000.<br /> [5] Garcia-Revilla, M.; Francisco, E.; Popelier, P.L.A. ; Martin-Pendas, A. M. ChemPhysChem 2013, 14, 1211.<br /> [6] Popelier, P. L. A. AIP Conf.Proc. 2012, 1456, 261.<br /> [7] Mills, M. J. L.; Popelier, P. L. A. Theor.Chem.Acc. 2012, 131, 1137.<br /> [8] Kandathil, S. M.; Fletcher, T. L.; Yuan, Y.; Knowles, J.; Popelier, P. L. A. J.Comput.Chem. 2013, in press, DOI: 10.1002/jcc.23333.<br /> Fri, 27 Sep 2013 14:15:55 +0200S_topological_approaches_2013_9M. Yáñez: Playing around with Beryllium Bonds http://video.upmc.fr//differe.php?collec=S_topological_approaches_2013&video=10Beryllium bonds share many characteristics with conventional hydrogen bonds (HBs) [1], and as in HBs the proton donor may become significant distorter, the formation of Be bonds are also accompanied by a dramatic distortion of the beryllium derivative. This deformation plays a crucial role as far as the relative stability trends are concerned since it amounts to about a 30% of the total interaction energy, but more importantly significantly enhances the electron acceptor capacity of Be containing Lewis acid [2]. When these two closed-shell kinds of interactions are present in the same system, like in the complexes between BeX2 derivatives and imidazole dimer, clear cooperativity effects are observed, which result in a mutual reinforcement of both non-covalent interactions. This permits to use the Be bonds to modulate or tune the strength of inter- and intra-molecular HBs [3]. Indeed, for more complex clusters, as those involving water trimers, both cooperative and anti-cooperative effects are found [4]. More importantly Be bonds lead to a significant change in the intrinsic properties of the Lewis base participating in the bond, in particular on its intrinsic acidity which is dramatically enhanced [5]. The possibility of building up ditopic systems, in which the acid site is a BeX group opens interesting possibilities to design new polymeric materials.<br /> <br /> [1] M. Yáñez., P. Sanz, O. Mó, I. Alkorta and J. Elguero, J. Chem Theor. Comput. 2009, 5, 2763-2771.<br /> [2] A. Martín-Sómer, A. M. Lamsabhi, O. Mó and M. Yáñez, Comput. Theor. Chem. 2012, 998, 74-79.<br /> [3] O. Mó, M. Yáñez, I. Alkorta and J. Elguero, J. Chem. Theory Comput. 2012, 8, 2293-2300.<br /> [4] L. Albrecht, R. J. Boyd, O. Mo and M. Yanez, Phys. Chem. Chem. Phys. 2012, 14, 14540-14547.<br /> [5] O. Mó, M. Yáñez, I. Alkorta, J. Elguero, J. Mol. Mod. 2013. dx.doi.org/10.1007/s00894-012-1682-y Fri, 27 Sep 2013 14:15:56 +0200S_topological_approaches_2013_10A. Martín Pendás: Decay rate of delocalization indices: towards a real space image of the insulating or metallic character of a materialhttp://video.upmc.fr//differe.php?collec=S_topological_approaches_2013&video=11Real space theories of the chemical bond have come of age, and are now grouped together under the umbrella name of Quantum Chemical Topology (QCT) [1], as originally proposed by Paul Popelier. Most of what is known in chemical bonding has been successfully reformulated using QCT techniques, that provide a wealth of quantities which are invariant under general orbital transformations. However, there is still no clear indication of what type of real space quantities, if any, might be used to discriminate between metals and insulators, in spite of several initial proposals, like those of Gatti and Silvi, or Contreras et. al. Recently, Baranov and Kohout have proposed that localization or delocalization indices might hold the clue [4]. However, their unrestricted Kohn-Sham approach is not devoid of possible criticisms. Here we address the problem from a molecular point of view, examining the analytic behavior of localization and delocalization indices in analytically solvable models and pointing towards the rate of decay of these quantities as a possible measure of long-range (metallic-like) or short-range (insulating-like) electron delocalization in materials [5].<br /> <br /> [1] Paul L. A. Popelier, Struct. Bond. 2005, 115, 1.<br /> [2] B. Silvi, C. Gatti, J. Phys. Chem. A, 2000, 104.<br /> [3] J. Contreras-García, A. Martín Pendás, J. M. Recio, B. Silvi , J. Chem. Theory Comput. , 2009, 5, 164.<br /> [4] A. Baranov, M. Kohout, Acta Cryst. A 2011, 67, C115.<br /> [5] A. Martín Pendás, in preparation. Fri, 27 Sep 2013 14:15:57 +0200S_topological_approaches_2013_11F. De Proft: Combined use of DFT based Reactivity Indices and the Non-covalent Index in the Study of Intermolecular Interactionshttp://video.upmc.fr//differe.php?collec=S_topological_approaches_2013&video=12Conceptual Density Functional Theory (sometimes also called DFT based reactivity theory or Chemical DFT) has proven to be an ideal framework for the introduction of chemical reactivity descriptors [1]. These indices are defined as response functions of the energy E of the system with respect to either the number of electrons N, the external potential v(r) or both. These definitions have afforded their non-empirical calculation and applications in many fields of chemistry have been performed, often combined with principles such as the electronegativity equalization principle of Sanderson and Pearson’s hard and soft acids and bases (HSAB) and maximum hardness principles. In this talk, we focus on recent studies in which a combined use of these reactivity indices and the Non-Covalent Interaction (NCI) Index [2] was carried out in order to scrutinize intermolecular interactions. In a first part, we focus on halogen bonding. Halogen bonds between the trifluoromethyl halides CF3Cl, CF3Br and CF3I, and dimethyl ether, dimethyl sulfide, trimethylamine and trimethyl phosphine were investigated using the HSAB concept with conceptual DFT reactivity indices, the Ziegler-Rauk type energy decomposition analysis [3], the Natural Orbital for Chemical Valence framework (NOCV) [4], and the NCI index. It is found that the relative importance of electrostatic and orbital (charge transfer) interactions in these halogen bonded complexes varies as a function of both the donor and acceptor molecules [5]. Hard and soft interactions were distinguished and characterized by atomic charges, electrophilicity and local softness indices. Dual descriptor plots indicate an orbital σ-hole on the halogen similar to the electrostatic σ-hole manifested in the molecular electrostatic potential. The characteristic signal found in the reduced density gradient versus electron density diagram corresponds to the non-covalent interaction between contact atoms in the NCI plots, which is the manifestation of halogen bonding within the NCI theory. The unexpected C–X bond strengthening observed in several cases was rationalized within the MO framework.<br /> <br /> In a second part of the talk, we present recent results on the use of the above mentioned quantities in the study of metal-metal interactions [6].<br /> <br /> [1] (a) R. G. Parr and W. Yang, Density Functional Theory of Atoms and Molecules, Oxford University Press, New York, 1989. (b) R. G. Parr and W. Yang, Ann. Rev. Phys. Chem. 46, 701 (1995). (c) H. Chermette, J. Comput. Chem. 20, 129 (1999). (d) P. Geerlings, F. De Proft and W. Langenaeker, Chem. Rev. 103, 1793 (2003). (e) P. W. Ayers, J. S. M. Anderson and L. J. Bartolotti, Int. J. Quant. Chem. 101, 520 (2005).<br /> [2] (a) E. R. Johnson, S. Keinan, P. Mori-Sanchez, J. Contreras-Garcia, A. J. Cohen and W. T. Yang, Journal of the American Chemical Society 132, 6498 (2010). (b) J. Contreras-Garcia, E. R. Johnson, S. Keinan, R. Chaudret, J. P. Piquemal, D. N. Beratan and W. T. Yang, J. Chem. Theor. Comput. 7, 625 (2011).<br /> [3] (a) F. M. Bickelhaupt and E. J. Baerends, Reviews in Computational Chemistry, 15, 1 (2000); (b) T. Ziegler and A. Rauk, Theoretica Chimica Acta 46, 1 (1977).<br /> [4] M. P. Mitoraj, A. Michalak and T. Ziegler, J. Chem. Theor. Comput. 5, 962 (2009).<br /> [5] B. Pinter, N. Nagels, W. A. Herrebout and F. De Proft, Chem. Eur. J. 19, 518 (2013).<br /> [6] B. Pinter, L. Broeckaert, J. Turek, A. Růžička and F. De Proft, in preparation.Fri, 27 Sep 2013 14:15:58 +0200S_topological_approaches_2013_12