524th MEETING Of the NORTHEAST TENNESSEE SECTION

Date: Monday, April 23, 2001

Speaker: Joseph R. Zoeller, NETS-ACS 20001 Speaker of the Year

Title: MOLYBDENUM CATALYZED CARBONYLATION OF ETHYLENE

Abstract: Zero-valent chromium group metals are generally regarded as inert in catalytic processes. However, with the choice of proper conditions, the relatively inexpensive chromium group catalysts are surprisingly active catalysts for the conversion of ethylene and carbon monoxide to either propionic acid or anhydride. This transformation operates at very high rates under low to moderate pressures (30-70 atm.) and temperatures (150-200 C). Mechanistic investigations using the most active catalyst of the group, Mo(CO)₆, imply catalysis is initiated by a rate limiting CO dissociation from Mo(CO)₆. Subsequent interaction of Mo(CO)₅ transfers an iodine atom from EtI cocatalyst, likely via an initial inner sphere, electron transfer process. Reaction of the resultant ethyl radical with Mo(CO)₆ likely generates odd electron Mo species which are capable of rapid catalysis via classical olefin carbonylation mechanisms. This discovery represents the first efficient carbonylation process based on the Cr group metals and a unique method for initiating carbonylation catalysis. Details of mechanistic investigation, including kinetics, in situ spectroscopic investigations, and by-product analysis, which led to our mechanistic conclusions, will be described. This mechanistic evaluation was used to improve the process and to aid in the discovery of new processes.

Biographical Sketch:

Joseph (Joe) Zoeller was born and raised on Long Island, NY. He received his B.S. Chemistry, from Hofstra Univ. in 1975. He began graduate studies at Purdue Univ. working for Bob Holton investigating ligand directed regio- and stereoselective ring closures using palladium. When Bob Holton left Purdue to move to Virginia Tech in 1978, Joe left with Bob to complete his graduate studies receiving his Ph.D. in Organic Chemistry from Virginia Tech in February of 1981.

After leaving Virginia Tech, Joe joined the Research Laboratories at Eastman Chemical Company where he began research in the area of synthesis gas based chemistries. Synthesis gas chemistry has continued to be the major theme of his research over the 20 years he has worked at Eastman. In this area, Joe has published or patented an extensive body of work regarding the generation and processing of acetate and propionate derivatives and the subsequent conversion of these acetates and propionates to more valuable downstream chemicals, such as acrylates and vinyl acetates. However, his research interests have not been limited to synthesis gas chemistry. He has also published or patented significant works in thermal chemistry, heterogeneous catalysis in carbon-carbon bond formation, and the generation of intermediates for crosslinking and photosensitizing polyesters. During his career with Eastman, Joe has been granted 40 patents, with an additional 16 patents pending, has published 20 papers and book chapters, co-edited a book, and has organized and edited print versions of 3 National ACS symposia. He has been active in his profession currently serving as associate editor of Catalysis Today, as the industrial chair of the "New Chemical Processes" section of Vision 2020, and has just completed service on the National Research Council’s panel on "Catalytic Process Technologies in Future Manufacturing." He has also been active in the community, particularly regarding educational issues, serving in numerous positions in the PTA and is currently a candidate for the Kingsport City School Board. He has been a member of the ACS since 1972 and is currently a Senior Research Associate in the Chemical Synthesis Research Laboratories of Eastman Chemical Company.