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Expanding the horizons of chemistry with the halogen bond

Expanding the horizons of chemistry with the halogen bond. Ruben D. Parra, Ph.D. Department of Chemistry, DePaul University Chicago, IL-USA. Ice Nanotubes. J. Chem. Phys., Vol. 113, No. 12, 5037-5040, 2000. Folding Oligoamides. Folding Oligoamides.

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Expanding the horizons of chemistry with the halogen bond

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  1. Expanding the horizons of chemistry with the halogen bond Ruben D. Parra, Ph.D.Department of Chemistry, DePaul University Chicago, IL-USA

  2. Ice Nanotubes J. Chem. Phys., Vol. 113, No. 12, 5037-5040, 2000

  3. Folding Oligoamides

  4. Folding Oligoamides PNAS 2002 vol. 99 no. 18 11583–11588

  5. Metal Complexation by Macrocycle Amides THEOCHEM 819 , 79–87, 2007

  6. Folding oligomers of difluorinatedthienylfurans Phys. Chem. Chem. Phys., 12, 523–532, 2010

  7. CuONanobarrels J. Vac. Sci. Technol. B 29(6), 1-5, 2011

  8. The Halogen Bond • Halogen bonding is the non-covalent interaction where halogen atoms function as electrophilic species.Angew. Chem. Int. Ed. 2008, 47, 6114 – 6127.

  9. Schematic representation of the electrostatic potential in covalently bound Cl, Br and I atoms.

  10. The Halogen Bond • Phys. Chem. Chem. Phys., 2010, 12, 7736–7747

  11. The Halogen Bond: Features • Electron density is anisotropicallydistributed around halogen atoms in organic halides. • The binding nature of XBs results in the D···X distances being shorter than the sum of the van derWaals radii of the involved atoms, and a strong tendency for Y-X…D linearity. • The formation of a halogen bond slightly lengthens the covalent Y-X bond.

  12. The Halogen Bond: Features • Halogen bonding has an impact on all research fields where the control of intermolecular recognition and self-assembly processes plays a key role. • The strength of a halogen bond increases with the electron-withdrawing nature of the atom they are covalently bound to. • The strength of a halogen bond follows the general trend Cl< Br < I.

  13. The strength of a halogen bond increases with the electron-withdrawing nature of the atom they are covalently bound to.

  14. The Halogen Bond: Features Amphiphilic character:

  15. Van der Waals Distances, Å

  16. The Halogen Bond: In protein-ligand environments, halogen bonds can be formed between a halogenated ligand and any accessible Lewis base in the binding pocket. the backbone carbonyl oxygen function is the most prominent Lewis base. halogen bonds can also be formed with side-chain groups, such as hydroxyls, carboxylates, sulfur, nitrogen, and the π surfaces of phenylalanine, tyrosine, histidine, and tryptophan

  17. O. Hassel, Science 1970, 170, 497

  18. Halogen bonding has been used for topochemical polymerization of olefines. • Halogen bonding and p…p stacking both control reactivity in the solid state. • Synthesis of tetrakis(4-pyridyl)cyclobutane isomer via templated photoreaction in the solid state. JACS. 2004, 126, 4500

  19. Halogen bonding at work: recent applications in synthetic chemistry and materials science CrystEngComm, 2013, DOI: 10.1039/C2CE26150B

  20. Some very Good Review Articles • Halogen Bonding Interactions in Molecular Crystals: From Early Recognition to Recent Developments . Journal of the Indian Institute of Science VOL 87:2 Apr–Jun 2007 • Principles and Applications of Halogen Bonding in Medicinal Chemistry and Chemical Biology J. Med. Chem.DOI: 10.1021/jm3012068 • Halogen bonding: from self-assembly to materials and biomoleculesCrystEngComm, 2013, AdvanceArticle DOI: 10.1039/C3CE90042H • Halogen bonding in metal–organic–supramolecularnetworks . Coordination Chemistry Reviews 254 (2010) 677–695

  21. Computational and Theoretical Chemistry 998 , 183–192, 2012 Research Project: N-X…N Interactions (X = H, Cl, Br, I) To examine the strength of the N-X…N interactions for X=Cl, Br, or I (halogen bond) relative to that for X=H (hydrogen bond). Formamidineand its monohalogenatedanalogues were used as model systems. The MP2 ab initio method, and the B3LYP density functional theory method were used.

  22. Model System: Monomer

  23. Model System: Cyclic Dimers

  24. Model System: Open Dimers

  25. Dimers

  26. Dimers

  27. Model System: Cyclic Trimer

  28. Model System: Cyclic Trimer

  29. Model System: Cyclic Trimer

  30. X…N

  31. QN-X…N

  32. X…X

  33. Linear correlation between N…X rcp and DEInteraction at the MP2 level

  34. Linear correlation between E(2) and DEInteraction at the MP2 level

  35. Tetramer Geometries

  36. Tetramer Geometries

  37. B3LYP Cyclic Geometries

  38. B3LYP average interaction energies (kcal/mol)

  39. Research Project: Concerted N…X…N, N…M…N and Orthogonal X…M Interactions as Polymeric Synthons Electrophilic and nucleophilic role of a halogen bond as a basis for polymer formation. Monohalogenatedformamidineand lithium formamidinate used as model reactive systems. MP2 Ab Initio method, and the B3LYP density functional theory method used.

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