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Professor
B.Sc., M.Sc. (Laurentian), Ph.D. (Queen's)
Office: S-421
Lab: S-420
Mailing Address:
Dr. H. Joly
Department of Chemistry & Biochemistry
Laurentian University
Sudbury, ON
P3E 2C6
Telephone:
(705) 675-1151, ext 2333, 2340
FAX: (705) 675-4844
Internet:
hjoly@laurentian.ca |
Metal-Atom-Mediated Chemical Transformations
The fundamental information concerning reactive intermediates and the mechanism and energetics by which they form is the basis for the development of experimental strategies to effect selective chemical transformations, vital for the pharmaceutical, electronics, and lithographic industries. Metals are often used as catalysts in organic synthesis. Much success has been obtained to date in terms of reducing reaction time and increasing product yield when metals are used to mediate the chemical transformations. In general, the areas of chemistry in which metal centres play a primary role suffer severely from a lack of basic information because of the relative youth of the field and the diverse nature of the metal and ligands employed. To improve upon the efficiency of catalyst systems factors such as a) the site of metal-organic interaction; b) the nature of the bonding interaction; c) the mechanism of the chemical trans-formation in the presence of metals and d) potential metal inhibitors must be known.
The principal theme of the research is the preparation of reactive organometallic intermediates using a 'high energy process' referred to as metal vapour synthesis with the view of developing novel synthetic methods. A 'rotating cryostat' (a specialized metal atom reactor) is the primary tool used in the synthesis of the organometallic species. This device consists of a stainless steel drum held in the centre of a reaction chamber which is maintained at ca. 10-7 Torr. During operation the liquid-nitrogen-filled drum rotates at 2000 rpm while the substrates and the metal vapour are introduced through portholes in the outer chamber. (See figure below.)
The metal vapour (produced by heating a metal resistively in a tungsten basket or a molybdenum pouch) is condensed on the cold surface of the rotating drum and bombarded with one or more reactants. The resulting reaction products are transferred under vacuum at 77 K into a sample tube for further analysis.
The advantage of this technique over the conventional methods of producing metal atoms is the ability to characterize the intermediates formed in the reaction by EPR, in situ IR and UV spectroscopy. By linking the nature of the intermediates with the products formed upon hydrolysis information con-cerning the reaction mechanism is obtained. The main technique used to study the resulting reaction products is GC-MS.
At present the research group is engaged in the:
a) characterization and study of the reactivity of intermediates resulting from Al atom reactions of thiols and organosulfides;
b) study of metal activation of C-halogen bonds;
c) reduction of aromatic compounds by metal atoms;
d) metal assisted coupling of alkenes and ketones;
e) comparing the efficiency of the cryostat technique to conventional methods of producing metal atoms.
Publications:
Jia Y, Joly H, Omri A.
Characterization of the interaction between liposomal formulations and Pseudomonas aeruginosa.
J Liposome Res. 20(2):134-46. (2010)
Jia Y, Joly H, Leek DM, Demetzos C, Omri A.
The effect of aminoglycoside antibiotics on the thermodynamic properties of liposomal vesicles.
Liposome Res. 2009 Jul 21. [Epub ahead of print]
Yimei Jia, Hélène Joly, Abdelwahab Omri
Liposomes as a carrier for gentamicin delivery: Development and evaluation of the physicochemical properties
International Journal of Pharmaceutics, 359, 254-263. (2008)
R. Bériault, R. Hamel, D. Chénier, R. Mailloux, H. Joly and V.D. Appanna
The overexpression of NADPH-producing enzymes counters the oxidative stress evoked by gallium, an iron mimetic.
Biometals., 20: 165-176. (2007)
Jianli Wang, Zhibin Ye, and Helen Joly
Synthesis and Characterization of Hyperbranched Polyethylenes Tethered with Polyhedral Oligomeric Silsesquioxane (POSS) Nanoparticles by Chain Walking Ethylene Copolymerization with Acryloisobutyl-POSS
Macromolecules, 40: 1353-1362. (2007) [PDF]
H. A. Joly, L. Beaudet and X. Dai
An EPR Study of the C-O Bond Activation of 1,2-Epoxybutane by Ground-State Al Atoms.
J. Phys. Chem. A, 110 (17) : 5656-64. (2006)
K. Béchamp, H. A. Joly, M. Levesque and L. Manceron
A combined EPR and Infrared Study of the Co(C6H6)1,2 complexes isolated in neat benzene in cryogenic matrixes.
J. Phys. Chem. A, 110 (18) : 6023-31. (2006)
H. A. Joly, J. Ashley, M. Y. Levesque and J. P. Rank
An EPR study of mononuclear Al species formed in the reaction Al atoms and cyclopropylamine at 77K
J. Phys. Chem. A, 110 (11): 3911-3919. (2006)
H. A. Joly, M. Y. Levesque, F. Koudra and J. P. Rank
Activation of C – Br by ground state aluminium atoms.
Chem. Phys. Lett., 420: 140-145. (2006)
H.A. Joly, J.A. Howard, & G.A. Arteca
EPR spectroscopic study of the reaction of ground-state Al atoms with cyclic alcohols in a rotating cryostat.
Phys. Chem. Chem. Phys. 3: 760-765. (2001) [Pdf]
H.A. Joly, J.A. Howard, & G.A. Arteca
EPR spectroscopic study of the reaction of ground-state Al atoms with acyclic alcohols in a rotating cryostat.
Phys. Chem. Chem. Phys. 3: 750-759. ( 2001) [Pdf]
H.A. Joly, M. Kepes, N. Roy, & J. Prpic
The reactivity of high-energy intermediates formed in the reactions of group 13 metal atoms and styrene
Can. J. Chem. 76: 400. (1998) [Pdf]
L. Manceron, M.E. Alikhani, & H.A. Joly
Infrared matrix isolation and DFT study of NiN2
Chem. Phys. 228: 73. (1998) [Pdf]
H.A. Joly & L. Manceron
The infrared spectrum of NiCO isolated in solid argon
Chem. Phys. 226: 61. (1997) [Pdf]