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April 05 2001
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I am presently enroled in the graduate studiesprogram at UPEI (University of Prince Edward Island); actually it is alittle more complex than that, but I am sure you don't want me to go intothat :-) . It is a wonderful place to be. My research is in the field ofinorgainc / physical chemisty. The department has recently upgraded (inthe last year) most of their the equipment, so we have all kinds of big,expensive toys. There is a new 300 MHz NMR, a nice infrared spectrometer,CV, fluorometer (I guess that is what you call it). Then there is our prideand joy the $100,000 dollar stopped flow from Hi-Tech. This is the onlyone like it in Canada. There are 2 other machines similar to ours in Canada,but ours has a double mixing option (which gives more flexibility withmaking measurements). Also, the building is only few years old (three orso) and has a bunch of funky little additions. My favouriate of these arethevac line pluming through the buliding (no more aspirators), the nitrogenline running through the research labs, and the deionized water on tap.I am not sure it this is common to other places, but I had never seen thesethings until I got here. It is all around, a great place to be. Thestudents here are wonderful, and the professors treat you like a friend.Just click if you want to check more aboutUPEI,and chemistry at UPEI.
If you want to see what I have been up to whileI have been here, click on the yellow titles below. There is a pictureof the macrocycle I have been working with, and two explanations of myresearch. Even if you have no understanding of chemistry you should beable to get through this with no trouble.
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Before you get into the chemistry you may want to read about the NewElement Discovered . ;-)
Comments about the ligand ormacrycle refer to the picture above.
My work centers around theinfluence the ligand (everything but the red Ni atom) places of redox chemistry(stealing or giving an electron from or to an atom). We have been studyingthe electron transfer reactions of complexes (the whole picture; also adifferent central metal (silver sphere) atom means different complex) witha variety of oxidizing and reducing agents (things that steal or give anelectron, respectively). The results of these reactions will be publishedsoon.... (famous last words)
There are a few potentialapplications for this complex. One area complexes turn up are in biologicalsystems. Probably one of the more exciting uses complexes, is as an anti-tumoragent. The coordination of nitrogen and oxygen atoms is comparable to bleomycinwhich is a know anti tumor agent (however, this is not to suggest thatmy molecule will cure cancer, but if that should happen, great!). Complexesturn up everywhere in biological systems. For example (for those that don'tknow) Hemoglobin is a complex. Iron is the central metal, and it is bondedto five nitrogens. Oxygen taken in from the lungs is bonded to the iron,and then piped through the blood vessels. Just a point of interest, cyanidekills by bonding to the iron in preference to oxygen, which prevents oxygenfrom getting into the blood. Cool huh.
My work has been directedto using these complexes as tools for removing rust from nuclear powerplants. We believe that the arrangement of atoms will allow the complexto stick to the corroded surface, reduce the rust (give an electron), and thereby making it soluble. Basically, the rust is dissolved using the complex.
We have just started intothe wonderful world of anti cancer research. Right now we are in the preliminarystages of the work. We are hoping to get some publishable results withina month. The work will involve using platinum, and trying to createa better drug then the standard cisplatin which is presently used in chemotherapy.As everybody is aware, chemotherapy (cisplatin) does a really nasty jobon the person as well as the cancer. We believe that our work will be ableto kill off the cancer, without the negative effects of cis platin. Letsjust hope it all goes smoothly.
(FYI = chemists have an bit ofa multiple personality problem; "We" is used to refer to either of me (hehe),my supervisor, the people in our lab, or any combination of the above)
The picture of the macrocycle is above.
We initially took this complex withNi in the 2+ oxidation state [Ni(II)L]+, and reactedit with [Ni(III)(non)2]3+ (non = 1,4,7-triazacyclononane).The reaction was followed using stopped-flow methods, under pseudo-firstorder conditions (Ni(II)L]+ in excess). The results were reallyunexpected!!! For this reaction (which we thought would be a simple oneelectron transfer), we have seen curvature in the kobs (observedrate constant) versus concentration of the complex plot. For a one electrontransfer we would expect the plot to be a straight line with some sortof slope, and it would pass through the origin.
We initially thought the curvaturewas the result of solubility limitations of the [Ni(II)L]+. When we changed the excess reagent to [Ni(III)(non)2]3+we did in fact get a straight line, which implies the curvature was dueto the limited solubility of [Ni(II)L]+. However, therewas still an intercept in the kobs vs conc. plot. We are investigatingthe possibility of an equilibrium process occurring. The data has beencollected, and massaged. The activation parameters seem to agree with theequlibrium hypothesis. So now all that is left is a CV for Marcus correlation,and then this will be off to the presses.
We have also tried the reactionbetween [Ni(III)L]2+ with Fe2+, to determine theligands potential for inner-sphere redox. It looks very promising. Aftercomparing the results of the kinetics experiments, and the water exchangerate for Fe2+ it at least appears possible that the mechanismis inner-shpere. We are awaiting CV results to do a Marcus correlationwhich should let us know if it is inner-sphere or outer-sphere. The CVis now up and running, so we should be able to get those experiments doneby the end of the week, here's hoping. Attempts to grow a crystal of abinuclear complex for X-ray diffraction have thus far proven unsuccessful.
As for the anti cancer stuff.It sounds really cool. I am very excited about it, and there is a lot ofinterest from other students in the department to get involved with thiswork. Once we have the results sent off for publication, I will flash upwhat has been going on. (hush, hush). For now the work will involve usingplatinum, and trying to create a better drug then the standard cisplatinwhich presently is used in chemotherapy. The drawback with cisplatin isthat the platinum metal is released into the body which kills the personfrom heavy metal poisoning. We believe that we will be able to make a platinumcontaining compound that will have the same effect on the cancer, yet notpoison the individual.
As of now, we have one platniumcontaining compound. I am in the characterization stages now. We have beentrying to get an 195Pt nmr, but that is proving to bea little more involved than a 13C. Although, they are allowingme to tune the nmr myself; great bit of fun.
It really is a lot of fun here.With the new $100,000 stopped flow with P3-400 to play with, it gets evenbetter. Our research grouphas a web page of its' own, so you might want to check it out. Alsothere is the UPEI page if you want toknow more about the university.
Email me at dhutchings@upei.ca
