SYNTHESIS OF CYCLIC AZOBENZENE ANALOGUES FOR INCORPORATION INTO OLIGONUCLEOTIDES, PEPTIDES AND POLYMERS

(A) In recent years, considerable amount of effort has contributed towards enhancing our understanding of the new photoswitch, cyclic azobenzene, particularly from the theoretical point of view. However, the challenging part with this system was poor efficiency of its synthesis from 2,2’- dinitrodibenzyl and lack of effective methods for further modification which would be useful to incorporate this system into biomolecules as a photoswitch. We report the synthesis of cyclic azobenzene and analogues from 2,2’-dinitrodibenzyl, which would allow for further incorporation of this cyclic azobenzene into biomolecules. Reaction of 2,2’-dinitrodibenzyl with zinc metal powder in the presence of triethylammonium formate buffer (pH-9.5) gave a cyclic azoxybenzene, 11,12-dihydrodibenzo[c,g][1,2]diazocine-5-oxide. The latter compound was converted into cyclic azobenzene analogues (bromo-, chloro-, cyano-, and carboxyl) through subsequent transformations. The carboxylic acid analogue was reacted with D-threoninol to give the corresponding amide, which readily undergoes photo-isomerization upon illumination with light. Upon illumination with light at 400 nm, approximately 70% of cis- isomer of amide was isomerized to trans- isomer. It was observed that cis- to trans- isomerization reached the maximum steady state of light transmission after approximately 40 min, whereas the trans- to cis- isomerization approximately acquired in 2 h to regain full recovery of light transmission. Cyclic azobenzene phosphoramidite was synthesized from DMT-protected D-threoninol linked cyclic azobenzene. (B) In recent years, there has been considerable interest invested towards the synthesis of azobenzene analogues for incorporation into proteins. Among the many azobenzene analogues, the synthesis of bi-functional cyclic azobenzene analogues for the incorporation into proteins is relatively new. In this thesis, we report the synthesis of a cyclic azobenzene biscarboxylic acid from 4-(bromomethyl)benzonitrile. (C) Azobenzene has been widely used in the field of polymer science to study the surface morphology and surface properties of polymers. In this thesis, we report the incorporation of cyclic azobenzene into a commercial polymer 2- (hydroxyethyl)methacrylate. Samples collected after 24 h from the reaction solution showed approximately 9% of incorporation of cyclic azobenzene into polymer compared to samples collected after 10 h, which showed approximately 6% incorporation.

Modeling Metal Protein Complexes from Experimental Extended X-ray Absorption Fine Structure using Computational Intelligence

Experimental Extended X-ray Absorption Fine Structure (EXAFS) spectra carry information about the chemical structure of metal protein complexes. However, pre- dicting the structure of such complexes from EXAFS spectra is not a simple task. Currently methods such as Monte Carlo optimization or simulated annealing are used in structure refinement of EXAFS. These methods have proven somewhat successful in structure refinement but have not been successful in finding the global minima. Multiple population based algorithms, including a genetic algorithm, a restarting ge- netic algorithm, differential evolution, and particle swarm optimization, are studied for their effectiveness in structure refinement of EXAFS. The oxygen-evolving com- plex in S1 is used as a benchmark for comparing the algorithms. These algorithms were successful in finding new atomic structures that produced improved calculated EXAFS spectra over atomic structures previously found.

Woodruff Family fonds, 1784 – 1983, (non-inclusive)

The Woodruff Family Collection: From the time the Woodruff Family came to Canada from the United States in 1795, they took an active role in the forming of their communities both in a civic and social manner. This is evident through the documents contained in this collection. The Woodruffs played an active role in the battles fought in Upper Canada and they were an integral part of the Village of St. Davids. They were educated, business-minded and socially engaged. They accumulated much of their fortune through land dealings. Much of this collection focuses on Samuel DeVeaux Woodruff who was principally a businessman. His dedication to his work is shown through his numerous undertakings. He made his mark on the Niagara Peninsula through his work on the railways, roads, marsh land revisions, canals and the paper industry. He was also involved with the founding of the Long Point Company and he took control of building DeVeaux Hall down to the last detail. His offspring inherited his work ethic and his business acumen. The people who married into the Woodruff Family also possessed key social, political and business ties. Anne and Margaret Clement were from a staunch Loyalist background. Samuel Zimmerman was instrumental to the founding of Niagara Falls and Judge Samuel DeVeaux left behind a legacy for poor and homeless boys in Niagara Falls, New York. The Woodruff Family undoubtedly left a mark on the Niagara Peninsula. This collection brings to light many endeavours of the family and their varied contributions.

Metal Stamp - Lion

Round stamp 2 cm in diameter. This has the image of a lion within a crown holding a flower. The inscription underneath is "sans changer" which means constant or without change. The stamp is 1 cm thick and it has a 1 cm stem protruding from it.

Metal Stamp - Woodruff Coat of Arms

Square metal stamp, 2 1/2 cm x 6 1/2 cm, with the words "P.C. Band, Toronto, Ontario" engraved on it. The bar is 1 cm thick.

Metal Stamp - Round with Amethyst

Round metal stamp which is 2 cm in diameter. The metal forms a cup above the seal which holds an amethyst piece. The amethyst is broken off and cracked.

Metal Bar - P. C. Band, Toronto, Ontario

Metal bar, 2 cm x 6 1/2 cm, with the words "P.C. Band, Toronto, Ontario" engraved on it.

Metal Button

Metal button 2 cm in diameter showing the crest of the right arm holding the honeysuckle (Woodruff crest). The button is inscribed in the inside. It has the number 50 on it and it says "N. R. Hayward, Long Acre, London, W. C."

The Feasibility of Using Vocalization Scoring as an Indicator of Poor Welfare During Cattle Slaughter

The article discusses the vocalization of cattle in six slaughter plants and the results indicate that "vocalization scoring could be used as a simple method for detecting welfare problems that need to be corrected".

Single-Molecule Magnets and Multifunctional Molecular Magnetic Materials Based on Polynuclear Metal Complexes

Our work on single molecule magnets and multifunctional magnetic materials is presented in four projects. In the first project we show for first time that heteroatomic-type pseudohalides, such as OCN-, can be employed as structure-directing ligands and ferromagnetic couplers in higher oxidation state metal cluster chemistry. The initial use of cyanato groups in Mn cluster chemistry has afforded structurally interesting MnII/III14 (1) and MnII/III/IV16 (2) clusters in which the end-on bridging cyanates show a preference in binding through their O-atom. The Mn14 compound shows entirely visible out-of-phase alternating currect signals below 5 K and large hysteresis loops below 2 K. Furthermore, the amalgamation of azido groups with the triethanolamine tripodal ligand in manganese carboxylate cluster chemistry has led to the isolation of a new ferromagnetic, high-nuclearity and mixed-valence MnII/III15Na2 (3) cluster with a large ground-state spin value of S = 14. In the second project we demonstrate a new synthetic route to purely inorganic-bridged, transition metal-azido clusters [CoII7 (4) and NiII7 (5)] and coordination polymers [{FeII/III2}n (6)] which exhibit strong ferromagnetic, SMM and long-range magnetic ordering behaviors. We also show that access to such a unique ferromagnetic class of inorganic, N-rich and O-free materials is feasible through the use of Me3SiN3 as the azido-ligand precursor without requiring the addition of any organic chelating/bridging ligand. In the last projects we have tried to bring together molecular magnetism and optics via the synthesis of multifunctional magnetic materials based on 3d- or 4f-metal ions. We decided to approach such challenge from two different directions: firstly, in our third project, by the deliberate replacement of non-emissive carboxylato ligands in known 3d-SMMs with their fluorescent analogues, without perturbing the metal-core structure and SMM properties (complexes 7, 8, and 9). The second route (last project) involves the use of naphthalene or pyridine-based polyalcohol bridging ligands for the synthesis of new polynuclear LnIII metal clusters (Ln = lanthanide) with novel topologies, SMM behaviors and luminescent properties arising from the increased efficiency of the “antenna” organic group. This approach has led us to the isolation of two new families of LnIII8 (complexes 10-13) and LnIII4 (complexes 14-20) clusters.