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M.A.(Tony)Whitehead Chemistry Departmen t McGill

M.A.(Tony)Whitehead Chemistry Departmen t McGill. Molecular Orbital Modelling of Dendrimers & Nano-Tubes. REVIEW OF TALKS GIVEN AT:. Friday, 28 th .August, 2008 FAPPMS 2008, Three Rivers Quebec. Saturday27th. June,2009 ACA 2009,Montreal, Quebec. Monday 15 th . June,2009

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M.A.(Tony)Whitehead Chemistry Departmen t McGill

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  1. M.A.(Tony)Whitehead Chemistry Department McGill Molecular Orbital Modelling of Dendrimers & Nano-Tubes REVIEW OF TALKS GIVEN AT: Friday, 28th.August, 2008 FAPPMS 2008, Three Rivers Quebec Saturday27th. June,2009 ACA 2009,Montreal, Quebec Monday 15th. June,2009 HPCS 2009 - Kingston, Ontario

  2. DRENDRITIC MOLECULES Dr Ashok Kakkar Rami Hourani Ye Tien

  3. Divergent Synthesis of DHBA-Based Dendrimers Bourrier O., Kakkar A. K., J. Mater. Chem. 2003, 13, 1306 Aggregate at cac

  4. PM3 optimised structures: DHBA-Based Dendrimers TOP VIEW SIDE VIEW Hourani R., Kakkar A., Whitehead M. A., J. Mater. Chem., 2005, 15, 2106–2113 Higher generation number… more globular structures giving well defined internal cavities

  5. DG 1 DLMO are orthogonal to all other DLMO and independent DG 2 DLMO are the same as DG1 in shape and energy:

  6. Encapsulation of DR1 in DHBA-Based Dendrimers Aggregation & Encapsulation . Blue Shift in λmax of DR1

  7. Divergent Synthesis: TEB-Based Dendrimers 1,3,5 Tri Ethynyl Benzene Hourani R., Whitehead M. A., and Kakkar A., Macromolecules, 2008, 41, 508.

  8. Structures of TEB-Based Dendrimers Development of turbine-like structure TOP VIEW SIDE VIEW 1,3,5 Tri Ethynyl Benzene

  9. Organometallic Dendrimers by Direct Replacement Lewis J. et al, J. Organomet. Chem., 1992, 425, 165. An easy route to include transition metal centres in the dendrimers

  10. DG1 TEB DHBA

  11. PLATINUM

  12. Using “Click” Chemistry To Build Dendrimers 1,3,5 Tri Ethynyl Benzene TEB 3.3 eq.

  13. Using “Click” Chemistry To Build Dendrimers Remove the silyl groups Then continue to build from the triple bonds

  14. -0.205 au. lumo +2 DG 1 DG 2 Same DLMO shape -0.018au lumo+8

  15. -0.314 au homo -0.016 au lumo+12 -0.022au lumo

  16. Centre: -0.317a.u. homo-1 Left: -0.331a.u homo-4 Right: -0.325a.u. homo-2 Bottom: -0.326a.u. homo-3

  17. SMI NANO TUBES Dr.Theo van de Ven Tom Lazzara

  18. 600 Lower π-π stabilization, higher maleimide chain interactions

  19. CONCLUSIONS Using insight and care and understanding the weaknesses Of the theories and programmes 1. Theory gave insight into dendrimer structures 2. Theory predicted possible metal containing dendrimers 3. Theory predicted nano-structures which were made 4. Theory helped to analyse the problems of SMI nano- structures and led to synthetic methods

  20. END

  21. WATER ON CALCITE AND ARAGONITE Joseph Kinghorn-Taenzer Intakhab Alam Zeeshan Water on Calcite breaks the Ca-O bond

  22. ARAGONITE CUT CRYSTAL CUT DOUBLE LAYER Side view SINGLE LAYER ATOMS FIXED

  23. 2H2O SIDE 2H2O SIDE 4H2O SIDE 4H2O TOP TOP SIDE

  24. SIDE TOP 2H2O SIDE and TOP pictures show 1) no bonds broken in the Aragonite Double Layer 2H2O lean closer to the surface

  25. 4H2O SIDE and TOP (1) and (2) Pictures show no bonds broken in the Aragonite Double Layer 4H2O arrange their H atoms to avoid each other

  26. Average Valence Bond H-bond distance = 1.97Å H-bond -1.045 HOMO +152 O…H = 1.067Å H-bond = 2.489Å

  27. -1.085au HOMO +118 O..H=1.53Å9; H-bond=2.578Å -1.054 auHOMO+146 O..H = 1.005Å; H-bond=2.579Å -1.088au HOMO + 116 O..H=0.977Å; H-bond=2.986Å -1.086au HOMO +117 O..H=1.068Å; H-bond=2.429Å

  28. -1.091au HOMO+115 O..H=1.005Å; H-bond=2.577Å

  29. DOUBLE LAYER: FOUR H2O Both water H (H1,H2) are bonded to different Osurface H1 -0.614au HOMO+289 O..H 1=0.986Å; H-bond=2.731Å rotate to show H-bond H2 -0.617au HOMO+288 O..H 2 =0.982Å; H-bond=3.79Å

  30. Both Hydrogen Bonds at the end CaO are in the same DLMO 268 rotate to show H-bond -0.676au HOMO+268 LEFT O..H=1.027Å; H-bond=2.453Å RIGHT O..H=1.052Å; H-bond=2.395Å

  31. CONCLUSIONS • Prediction of 3D structures of organic and Sn and Pt dendrimers • Prediction of the form of nano tubes from SMI • Prediction that unlike calcite which dissolves in Water, • Aragonite forms weak H-bonds and does not dissolve.

  32. THEORETICAL METHODS FOR CALCULATIONS 1 Molecular Mechanics: Balls and Springs tas 2 Quantum Mechanics n3 n4 catastrophe Neglect of Diatomic Differential Overlap 3 Molecular Dynamics Newtonian Dynamics n3 PM3 Large parameter space 2a Density Functional theory; n3

  33. Research Supported: The NSERC (CANADA): Discovery Grant Summer Undergrad Research Student 2008: Intakhab Alam Zeeshan Le Fonds québécois de la recherche sur la nature et les technologies. Doctoral Scholarships: Tom Lazzara, 2007 Rami Hourani, 2007 Centre for Self-Assembled Chemical Structures: Summer Undergrad Research Award, 2008 Ye Tian: SIGMA XI: Grant in Aid of Research: Tom Lazzara, 2007 Rami Hourani, 2007

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