Lack of reproducibility triggers retractions of Nature Materials articles

The authors of a highly cited 2015 paper in Nature Materials have retracted it, after being unable to reproduce some of the key findings.

The move prompted the journal to also retract an associated News & Views article.

Here’s the retraction notice for “Fast and long-range triplet exciton diffusion in metal–organic frameworks for photon upconversion at ultralow excitation power:”

We wish to retract this Article due to concerns with some data related to upconversion in the solid-state samples presented in Fig. 4d,e, and to the reproducibility check of the triplet diffusion constant provided in the Supplementary Information.

In this Article, we reported fast triplet energy migration and efficient photon upconversion at low excitation intensity in metal–organic frameworks (MOFs). We have since been able to observe the upconverted emission from MOFs both in benzene dispersions and in polymeric films; hence, the concept of photon upconversion in MOFs based on triplet energy migration remains valid. However, we are now unable to observe solid-state upconversion emission at the low excitation intensity reported in Fig. 4d,e, and to quantitatively reproduce the triplet diffusion constants in MOFs reported in Supplementary Figs 8–13 and Supplementary Tables 1–3. Since these are key parameters of this paper, all authors wish to retract this Article. We deeply regret these circumstances and sincerely apologize to the scientific community for the inconvenience this publication has caused to others.

The paper has been cited 36 times, according to Clarivate Analytics’ Web of Science, formerly part of Thomson Reuters, earning it a Highly Cited designation.

Asked to comment about the circumstances of the retraction, co-corresponding author Nobuo Kimizaka told Retraction Watch:

At this moment​ this matter has been under investigation by​ ​the formal investigation panel​ ​of our University ​and we are not allowed to ​answer ​​your question​ until the committee reaches a conclusion. It will take a few months more and then will be announced to public​ in general.

The retraction also led to the retraction of an associated News & Views article:

In view of the fact that the Article by P. Mahato et al. (Nature Materials14, 924–930; 2015) has been retracted by the authors, we wish to retract this News & Views highlighting the study as it relied on the validity of the data presented therein.

The News & Views has been cited five times.

We’ve seen this kind of thing before, from another Nature journal, although in one case the News & Views article only earned a warning notice.

Update 1/3/17 1:49 p.m. eastern: We’ve heard from the first author of the retracted News & Views, Yoan Simon, who told us:

It is never a nice thing to have to retract a paper but in agreement with the editorial team, we decided it was the right thing to do based on the issues with the original article.

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