JACS retracts polymer paper over data concerns
The Journal of the American Chemical Society has retracted a 2009 paper on ethylene polymerization after the authors said they were unable to replicate their findings.
The article, “Bimetallic Effects for Enhanced Polar Comonomer Enchainment Selectivity in Catalytic Ethylene Polymerization,”came from the lab of Tobin Marks, a highly decorated — and grant-and-royalty-generating — chemist at Northwestern University.
ChemBark this week reported that the retraction seems to have been prompted by a reader who contacted the blog and the journal in August, raising questions about the data in the article. Check out the post, because it highlights particular trouble spots in the figures.
According to the retraction notice:
The authors have been unable to reproduce the synthesis and spectroscopic characterization of the ethylene/acrylate copolymer described in this article. Accordingly, the authors are retracting this publication due to concerns over the validity of the aforementioned data. The authors regret any confusion that may have been created by publication of this work.
In contrast, the results reported in related publications regarding the synthesis of a binuclear catalyst and its ethylene homopolymerization properties,1 and on ligand steric and fluoroalkyl substituent effects on enchainment cooperativity and stability in bimetallic nickel(II) polymerization catalysts,2 have been reproduced.
The two references are to 1) Rodgriguez, B.A.; Delferro, M.; Marks, T.J. Organometallics 2008, 27, 2166-2168; and 2) Weberski, M.P.; Chen, C.; Delferro, M.; Marks, T.J. Chem. Eur. J. 2012, 18, 10715-10732.
The study has been cited 53 times
yet to be cited, according to Thomson Scientific’s Web of Knowledge.
Marks was the subject of a profile in Crain’s Chicago Business last April, which reported that he has brought Northwestern “more than $100 million in grants and royalties” since coming to the school in 1970.
He ranks fifth among Chicago-area inventors, with 126 U.S. patents since 1980, according to the database compiled by Ms. [Deborah] Strumsky, a researcher at the University of North Carolina at Charlotte. Mr. Marks estimates his total patent count tops 200.
Marks didn’t respond to our request for comment. But ChemBark said its attempt to reach him by email was met with this reply from Northwestern:
Your inquiry to a Northwestern University professor, Tobin Marks, was referred to me, as I am the chief communications officer for Northwestern.
As you note in your email, two Northwestern University faculty members and a former Ph.D. student have retracted a publication that appeared several years ago in the Journal of the American Chemical Society. The authors are Brandon A. Rodriguez, who received a Ph.D. from Northwestern in 2009, Tobin Marks, a professor of chemistry, and Massimiliano Delferro, a research assistant professor of chemistry. The article was retracted because the authors were unable to reproduce a portion of the data described in the article.
Northwestern University has established processes and procedures for reviewing issues relating to research integrity. If concerns were to be raised regarding the data that was the subject of the retraction, the University would use those procedures in its review. Part of those procedures, which follow the steps mandated by the federal government, is that any review remains confidential.
Thank you for your interest in Northwestern.
ChemBark promises a follow-up post that might shed more light on this case.
Update, 12:30 p.m. Eastern: Corrected number of citations with strike-through. For some reason, Thomson Scientific has two entries for this paper, one of which said zero citations. The other, which we’ve now found, says 53.
Hat tip: Rolf Degen