Report on inorganic chemistry programming.
Report on Inorganic Chemistry Programming
The organizing committee under the chairmanship of Gordon Bushnell, MCIC, provided a lively programme of 157 papers, at the 72nd Canadian Chemical Conference in Victoria many of which were presented as contributions to four formal symposia.
The symposium on the biological aspects of inorganic chemistry, organized by Bushnell, opened with talks by T.M. Loehr and R.E. Stenkamp on the Raman spectroscopy and X-ray of multinuclear iron proteins, such as hemerythrin. After coffee the subjects were the biological effect of arsenicals, and a contribution by E.T. Adman, on the role of H-bonding in defining blue copper protein active sites.
The afternoon session was on cytochromes c, [b.sub.5], and P450 and dealt with the protein structure, spectroscopy, catalysis, and electrochemistry of these systems. The invited talks were G. Brayer, MCIC, A.G. Mauk, FCIC, and P.R. Ortiz de Montellano.
On the second day, B.R. James, FCIC, gave an account of developments in ruthenium porphyrin chemistry, and the symposium closed with several other aspects of coordination chemistry and structure, including some technetium chemistry.
The attendance at the half day session on the chemistry of group 15 and 16 elements ranged from 45 to 60 people. Both the polished presentations, five of which were by graduate students, and the lively discussion signified that main group chemistry is flourishing in Canada. Among the highlights were the reports of binary cyclic selenium-nitrogen cations by the Passmore group and the discovery of related carbon-nitrogen-selenium cations and radicals by Oakley and co-workers. These papers exemplified a widespread increase in selenium chemistry among inorganic chemists.
Steve Stobart's symposium on bimetallic and polymetallic complexes ran to six full sessions (one jointly with the symposium on kinetics and catalysis, summarized below), with major lectures by S.A.R. Knox, A.L. Balch, Richard Puddephatt, FCIC, R.K. Pomeroy, MCIC, J.R. Winkler and L.K. Thompson, MCIC. A detailed account of the proceedings was not available at press time.
Brian James and Alex McAuley, FCIC, organized the symposium on kinetic and catalysis, the intent of which was to bring together researchers in a wide variety of laboratories both industrial and academic whose area of investigation is related to mechanism. There was extensive representation from both sides of the Canada/US border. The symposium got off to an auspicious start with an excellent lecture by Rick Eisenberg (Rochester) on hydrogenation and hydrogen transfer reactions involving para-hydrogen. Bob Morris, MCIC (Toronto) then described reactions of dihydrogen complexes of the iron group. Data on the [Eta.sup.2] [-H.sub.2] distances may be derived from nmr spectroscopy. Biological aspects were covered by Teddy Traylor (San Diego) on oxidations catalysed by cytochrome [P.sub.450] and Rick Fincke (Oregon) posed new questions in the key elementary steps in coenzyme [B.sub.12]-dependent rearrangement reactions. The identification of some intermediate provides more details of the mechanism, pointing especially to the significant role of the protein.
The industrial sector provided several very interesting papers. Dennis Riley (Monsanto) described the use of cobalt coordiantion complexes as homogeneous catalysts in molecular-oxygen driven oxidation decarboxylations. Such reactions are novel and extremely selective when carried out at the natural pH of the free acid substrate. Henry Bryndza (Du Pont) presented an excellent overview of forays into organometallic thermochemistry leading to a correlation between [L.sub.n] M-X and H-X bonds dissociation energies. Such data may permit predictions for [L.sub.n] M-X bonds as yet unmeasured. Darryl Fahey (Phillips Petroleum) provided insights into the production of ethylene glycol from synthesis gas. The slow step kinetically is the formation of formaldehyde. Approaches using added paraformaldehyde look promising. Again, key intermediates have been identified. Devinder Majahan (Brookhaven) described studies aimed ultimately at using natural gas, but initially using CO to synthesize [C.sub.1] and higher oxygenated products (methanol, methyl formate). Homogeneous catalysis is again an important feature.
The high catalytic activity exhibited by organosilicon compounds was the subject of a lecture by John Harrod, FCIC (McGill). In the case of titanocene complexes, there is esr evidence for species involving alkyl titanium (III). The air-catalysed oxidation of thiosalts was described by Gary Rempel, FCIC (Waterloo). The use of copper polymers based on vinyl pyridine has provided information on reactions in solution and at the surface of the polymer. Such problems must be tackled in view of the environmental consequences of thiol oxidation.
The final session was a joint symposium with the emphasis on reactivity of bimetallic and polymetallic complexes. Duane Dombeck (Union Carbide) dealt with the hydrogenation of carbon monoxide mediated by metal carbonyl complexes. Particular emphasis is placed on production of ethylene glycol and alcohols. Puddephatt (Western) discussed approaches to activation of bonds such as C-O, C-F and C=S at mono-, bi-and trimetallic centres. The activation of CO was also the subject of reactions involving early and late binuclear species. Crystallographic data and esr analysis of species involving Ti-Ni and Ti-Rh heterobimetallics provides information for communication between the participating metal centres.
Many other papers were presented at the general and poster sessions. The quality was uniformally high. The large turn-out at the poster session and the attendance of over 50 people at 11 pm on that evening attests to the interest generated and to the healthy state of inorganic chemistry in Canada!
The organizers are to be congratulated on a beautifully-organized and stimulating conference. I thank Gordon Bushnell, Alex McAuley and Tris Chivers, FCIC, for providing first-hand accounts of the symposia in which they were involved.
Tom Swaddle, FCIC Chairman Inorganic Chemistry Division
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|Title Annotation:||72nd Canadian Chemical Conference and Exhibition|
|Publication:||Canadian Chemical News|
|Date:||Oct 1, 1989|
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