Simon Fraser University
Branda
branda_2006_pic

Neil R. Branda


Professor and Canada Research Chair in Materials Science
Executive Director, Molecular Systems, 4D LABS


B.Sc. - University of Toronto
Ph.D. - Massachusetts Institute of Technology

Room 7073 (TASC2)
(778) 782-8061 (office)   778-782-3765 (fax)
nbranda@sfu.ca

Organic Materials

molecular switches, photochromism and electrochromism, molecular recognition and supramolecular chemistry

We are motivated by the vision of molecules as the components of nano-scale machines - machines that like their macroscopic counterparts, require controllable moving parts, ways to harvest and process energy, molecular circuitry, on-off switches, logic gates and information storage devices. Our research focuses on designing mechanisms to control structure and function relationships in molecules using molecular recognition, supramolecular chemistry and molecular switching strategies.

 

Specific goals include:

 

the use of molecular switches triggered by light (photochromic) and electricity (electrochromic),
the use of allosteric cofactors to influence host-guest interactions, and
the self-assembly of new materials using hydrogen bonding and metal coordination.


For more details, visit our group home page.



Patents

  1. "Photochromic and Electrochromic Compounds and Synthesis and Use Thereof" Wüstenberg, B.; Lemieux, V.; Gauthier, S. Branda, N. R., PCT Appl: PCT/CA2006/000862; national phase in Canada, US, Europe, Japan.
  2. "Photochromic and Electrochromic Compounds and Methods of Synthesizing and Using Same" Peters, A.; Wigglesworth, A. J.; Branda, N. R., US appl: 10/523965; CA appl: 2494920; JA appl: 2004-526557.
  3. "Photochromic Polymers and Methods of Synthesizing Same" Myles, A. J.; Branda, N. R., USP: 7,041,763; CA appl: 2416016; JA appl: 2002-512261.

Representative Publications (1998 - on)

  1. "Regulation of Human Carbonic Anhydrase I (hCAI) Activity by a Photochromic Inhibitor" Vomasta, D.; Högner, C.; Branda, N. R.; König, B. Angew. Chem. Int. Ed. 2008, on-line.

  2. "High-Contrast Fluorescence Switching Using a Photoresponsive Dithienylethene Coordination Compound" Zhao, S.; Al-Atar, U.; Pace, T. C. S.; Bohne, C.; Branda, N. R. J. Photochem. Photobiol. A. 2008, on-line.

  3. "Modulating Chemical Reactivity Using a Photoresponsive Molecular Switch" Samachetty, H. D. Lemieux, V.; Branda, N. R. Tetrahedron. 2008, 64, 8392-8300.

  4. "Modulating the Lewis Acidity of Boron Using a Photoswitch" Lemieux, V.; Spantulescu, M. D.; Baldridge, K. K.; Branda, N. R. Angew. Chem. Int. Ed. 2008, 120, 5112-5115. (Special mention in Nature, Chemistry, June 2008.)

  5. "Supramolecular Metal-polypyridyl and Ru(II) Porphyrin Complexes. Photophysical, EPR and Electrochemical Studies" de Biani, F.; Grigiotti, E.; Laschi, F.; Zanello, P.; Juris, A.; Prodi, L.; Chichak, K.; Branda, N. Inorg. Chem. 2008, 47, 5425-5440.

  6. "Reversible and Amplified Fluorescence Quenching of a Photochromic Polythiophene" Finden, J.; Kunz, T.; Neil R. Branda, N. R.; Wolf, M. O. Adv. Mater. 2008, 20, 1998-2002.

  7. "Creating a Reactive Enediyne Using Visible Light: Photocontrol of the Bergman Cyclization" Sud, D.; Wigglesworth, T. J.; Branda, N. R. Angew. Chem. Int. Ed. 2007, 46, 8017-8019.

  8. "Bidirectional Ring-Opening and Ring-Closing of Cationic 1,2-Dithienylcyclopentene Molecular Switches Triggered with Light or Electricity" Gorodetsky, B.; Branda, N. R. Adv. Funct. Mater. 2007, 17, 786-796.

  9. "Integrating Molecular Switching and Chemical Reactivity Using Photoresponsive Hexatrienes" Samachetty, H. D.; Branda, N. R. Pure Appl. Chem. 2006, 78, 2351-2359.

  10. "Selective and Sequential Photorelease Using Molecular Switches" Lemieux, V.; Gauthier, S.; Branda, N. R. Angew. Chem. Int. Ed. 2006, 45, 6820-6824.

  11. "A Family of Multi-Addressable, Multi-Colored Photoresponsive Copolymers Prepared Using ROMP" Wigglesworth, T. J.; Branda, N. R. Chem. Mater. 2005, 17, 5473-5480.

  12. "A Photoswitchable Donor–π–Acceptor System Based on a Modified Hexatriene Backbone" Wüstenberg, B.; Branda, N. R. Adv. Mater. 2005, 17, 2134-2138.

  13. "Electrochemically Induced Dethreading of a 2-Pseudorotaxane Based on the 1,2-Bis(4,4’-pyridinium)ethane/24-crown-8 ether Motif" Gorodetsky, B.; Branda, N. R. Tetrahedron Lett. 2005, 43, 6761-6763.

  14. "Photochromic Phosphine Ligands" Sud, D.; McDonald, R.; Branda, N. R. Inorg. Chem. 2005, 44, 5960-5962.

  15. "Reactivity-Gated Photochromism of 1,2-Dithienylethenes for Potential Use in Dosimetry Applications" Lemieux, V.; Branda, N. R. Org. Lett. 2005, 7, 2967-2972.

  16. "Chiral Discimination in Photochromic Helicenes" Wigglesworth, T. J.; Sud, D.; Lekhi, V. S.; Norsten, T. B.; Branda, N. R. J. Am. Chem. Soc. 2005, 127, 7272-7273.

  17. "Photomodulation of Nucleophilicity in a Pyridine-Functionalized 1,2-Dithienylcyclopentene" Samachetty, H.; Branda, N. R. Chem. Commun. 2005, 2840-2842.

  18. "High-Content Photochromic Polymers Based on Dithienylethenes" Wigglesworth, T. J.; Myles, A. J.; Branda, N. R. Eur. J. Org. Chem. 2005, 1233-1238.

  19. "Photoswitching of Catalysis Using Metal-Dithienylethenes Complexes" Sud, D.; Norsten, T. B.; Branda, N. R. Angew. Chem. Int. Ed. Engl. 2004, 44, 2019-2021.

  20. "Electrochemical Reduction of an Imidazolium Cation: A Convenient Preparation of Imidazol-2-ylidenes and Implications for Chemistry in Ionic Liquids" Gorodetsky, B.; Ramnial, T.; Branda, N. R.; Clyburne, J. A. C. Chem. Commun. 2004, 1972-1973.

  21. "Reductive Electrochemical Ring-Closing of a Photochromic 1,2-Dithienylcyclopentene Dication" Gorodetsky, B.; Samachetty, H. D.; Donkers, R. L.; Workentin, M. S; Branda, N. R. Angew. Chem. Int. Ed. 2004, 43, 2812-2815.

  22. "Photoregulation of Luminescence Quenching in Photochromic Porphyrin-Phenoxynaphthacenequinone Co-Polymers" Myles, A, J.; Gorodetsky, B.; Branda, N. R. Adv. Mater. 2004, 16, 922-925.

  23. "Ultra-High-Density Photochromic Main-Chain 1,2-Dithienylcyclopentene Polymers Prepared Using ROMP" Wigglesworth, T, J.; Branda, N. R. Adv. Mater. 2004, 16, 123-125.

  24. "Structural Studies on Hydrogen-Bonding Receptors for Barbiturate Guests That Use Metal Ions as Allosteric Inhibitors" Al-Sayah, M. H.; McDonald, R.; Branda, N. R. Eur. J. Org. Chem. 2004, 173-182.

  25. "Photochromic Porphyrins" Gorodetsky, B.; Sud, D.; Norsten, T. B.; Myles, A. J.; Branda, N. R. J. Porphyrins Phthalocyanines 2003, 7, 313-317.

  26. "A Multi-Addressable Photochromic 1,2-Dithienylcyclopentene-Phenoxynaphthacenequinone Hybrid" Myles, A, J.; Wigglesworth, T, J.; Branda, N. R. Adv. Mater. 2003, 15, 745-748.

  27. "Electrochemically induced ring-closing of photochromic dithienylcyclopentenes" Peters, A.; Branda, N. R. Chem. Commun. 2003, 955-954.

  28. "Electrochromism in Photochromic Dithienylcyclopentenes" Peters, A.; Branda, N. R. J. Am. Chem. Soc. 2003, 125, 3404-3405.

  29. "Novel Photochromic Compounds Based on the 1-Thienyl-2-vinylcyclopentene Backbone" Peters, A.; Vitols, C.; McDonald, R.; Branda, N. R. Org. Lett. 2003, 5, 1183-1186.

  30. "Synthesis, spectral and electrochemical investigations of bichromophoric pentads possessing tetraazaporphyrin and (bipy)2RuII/(phen)2RuII moieties" Prasad, A. R.; Murguly, E.; Branda, N. R. Chem. Commun. 2003, 488-489.

  31. "Novel Photochromic Homopolymers Based on 1,2-Bis(3-thienyl)cyclopentene Derivatives" Myles, A. J.; Branda, N. R. Macromolecules 2003, 36, 298-303.

  32. "Regulating π-conjugated pathways using a photochromic 1,2-dithienylcyclopentene" Peters, A.; McDonald, R.; Branda, N. R. Chem. Commun. 2002, 2274-2275.

  33. “1,2-Dithienylethene Photochromes and Non-Destructive Erasable Memory” Myles, A. J.; Branda, N. R. Adv. Funct. Mater. (Feature Article) 2002, 12, 167-173.

  34. "Protons as the Trigger to Regulate Hydrogen-Bonding Receptors" Al-Sayah, M. H.; Branda, N. R. Org. Lett. 2002, 4, 881-884.

  35. "Controlling Allostery Using Redox Chemistry" Al-Sayah, M. H.; Branda, N. R. Chem. Commun. 2002, 178-179.

  36. "Strong and directed association of porphyrins and iron(terpyridine)s using hydrogen bonding and ion pairing" Norsten, T. B.; Chichak, K.; Branda, N. R. Tetrahedron (invited for a Special Issue on Directed Self-Assembly) 2002, 58, 639-651.

  37. "The Construction of Ruthenium(II)salophen Assemblies Using Axial Coordination" Chichak, K.; Jacquemard, U.; Branda, N. R. Eur. J. Inorg. Chem. 2002, 357-368.

  38. "A remarkably stable hydrogen-bonded porphyrin-iron(terpyridine) ion pair" Norsten, T. B.; Chichak, K.; Branda, N. R. Chem. Commun. 2001, 1794-1795.

  39. "Reversible [7]-Thiahelicene Formation Using a 1,2-Dithienylcyclopentene Photochrome" Norsten, T. B.; Peters, A.; McDonald, R.; Wang, M.; Branda, N. R. J. Am. Chem. Soc. 2001, 123, 7447-7448.

  40. "Nondestructive Data Processing Based on Chiroptic 1,2-Dithienylethene Photochromes" Murguly, E.; Norsten, T. B.; Branda, N. R. Angew. Chem. Int. Ed. Engl. 2001, 40, 1752-1755.

  41. "Axially-Coordinated Porphyrinic Photochromes for Nondestructive Information Processing" Norsten, T. B.; Branda, N. R. Adv. Mater. 2001, 13, 347-349.

  42. "Photoregulation of Fluorescence in a Porphyrinic Dithienylethene Photochrome" Norsten, T. B.; Branda, N. R. J. Am. Chem. Soc. 2001, 123, 1784-1785.

  43. "Rigid, Cross-conjugated Macrocycles: A Porous Alternative to 4,4'-Bipyridines in Supramolecular Chemistry" Campbell, K.; McDonald, R.; Branda, N. R.; Tykwinski, R. R. Org. Lett. 2001, 3, 1045-1048.

  44. "Coordination Complexes of â-Thioether Appended Tetraazaporphyrin" Prasad, R.; Kumar, A.; Murguly, E.; Branda, N. R. Inorg. Chem. Commun. 2001, 4, 219-222.

  45. "Controlling Photoinduced Electron Transfer within a Hydrogen-Bonded Porphyrin-Phenoxynaphthacenequinone Photochromic System" Myles, A. J.; Branda, N. R. J. Am. Chem. Soc. 2001, 123, 177-178.

  46. "Limited Photochromism in Covalently Linked Double 1,2-Dithienylethenes" Peters, A.; McDonald, R.; Branda, N. R. Adv. Mater. Opt. Electron. 2000, 10, 245-249.

  47. "Chiral Discrimination in Hydrogen-Bonded [7]Helicenes" Murguly, E.; McDonald, R.; Branda, N. R. Org. Lett. 2000, 2, 3169-3172.

  48. "Novel Synthesis of Photochromic Polymers via ROMP" Myles, A. J.; Branda, N. R. Org. Lett. 2000, 2, 2749-2751.

    "Metal Ions as Allosteric Inhibitors in Hydrogen-Bonding Receptors" Al-Sayah. M. H.; Branda, N. R. Angew. Chem. Int. Ed. Engl. 2000, 39, 945-947.

  49. "The metal-directed self-assembly of three-dimensional porphyrin arrays" Chichak, K.; Branda, N. R. Chem. Commun. 2000, 1211-1212.

  50. "Axially coordinated porphyrins as new rotaxane stoppers" Chichak, K; Walsh, M. C.; Branda. N. R. Chem. Commun. 2000, 847-858.

  51. "Porphyrinic Phenoxynaphthacenequinones" Myles, A. J.; Branda, N. R. Tetrahedron Lett. 2000, 41, 3785-3788.

  52. "Tautomerism of 4-hydroxyterpyridine in the solid, solution and gas phases: an X-Ray, FT-IR and NMR study" Murguly, E.; Norsten, T. B.; Branda, N. R. J. Chem. Soc., Perkin Trans. 2. 1999, 2789-2794.

  53. "Self-assembly of a linear multi-component porphyrin array through axial coordination" Chichak, K.; Branda, N. R. Chem. Commun. 1999, 523-524.

  54. "The self-assembly and spontaneous resolution of a hydrogen-bonded helix" Norsten, T.; Branda, N. R. Chem. Commun. 1999, 719-720.

  55. "A starburst porphyrin polymer: a first generation dendrimer" Norsten, T.; Branda, N. R. Chem. Commun. 1998, 1257-1258.