RETRACTED ARTICLE: Synthesis and characterization of trimeric phosphazene based ionic liquids with tetrafluoroborate anions and their thermal investigations
Authors: Ali Destegül
Yusuf Yerli
Çiğdem Çakırlar
Hüseyin Akbaş
Zeynel Kılıç
Ahmet Karadağ
Fatih Sen
Journal: Scientific Reports (2020)
Discipline: Multidisciplinary
Keywords: quaternized compounds; phosphazene based ionic liquids; elemental CHN analyses; spectroscopic analyses; thermal properties
Affiliations: Department of Chemistry, Faculty of Arts and Sciences, Yozgat Bozok University, 66200, Yozgat, Turkey. ., Department of Chemistry, Faculty of Arts and Sciences, Gaziosmanpaşa University, Tokat, Turkey., Department of Physics, Gebze Technical University, Kocaeli, Turkey., Department of Physics, Yıldız Technical University, Istanbul, Turkey., Department of Chemistry, Ankara University, Ankara, Turkey., Department of Biochemistry, University of Dumlupınar, Kütahya, Turkey. .

Abstract:  The quaternized compounds (PzIL1-9) reacted with sodium tetrafluoroborate (NaBF4) to generate phosphazene based ionic liquids (PzILs), PzIL1a-9a. The newly synthesized ionic compounds (PzIL1a-9a) were verified using elemental CHN analyses and functional and spectroscopic (FTIR and 1H, 13C, 31P-NMR) analyses techniques. The thermal properties of PzIL1a-9a were investigated using thermogravimetric analysis (TGA). According to the initial decomposition temperature values calculated based on the TGA thermograms, PzIL7a (213 °C) was recognized to be more thermally stable than the other PzILs studied. PzIL1a-9a exhibited good solubility in the water and demonstrate a typical dielectric relaxation behavior, conductivity levels for both low and high-frequency regions. AC conductivity mechanisms and dielectric relaxation behavior of each sample are investigated by fabricating parallel plate capacitors. 

Retracted: Yes

PubPeer comments:
 Figure 1 appears to show some unexpected repetitive areas. First, here is the full figure: ![file] Here is detailed view of the top graph, with repetitive areas marked in pink and blue. ![file] , 
 In Figure S1, in the supplemental, similar repeating motifs may be visible. Here is the overview of the complete Figure S1. ![file] Here is a detailed view of the PzIL8a spectrum (bottom panel in Figure S1), with potentially repetitive areas marked with boxes of the same color: ![file] , 
 Figure S2, middle panel: ![file] , 
 #2 I have concerns about the peaks too. ![file] , 
 In this publication, 31P NMR spectra were taken on the same device (31P{1H} NMR spectra were recorded on Agilent 600 MHz Premium COMPACT NMR spectrometer) and the motifs repeated in the baseline are the repetition of the noise signals of the device. Since the compounds have three phosphorus atoms in the N3P3 phosphazene ring and are AX2 type spectra, a triplet and a doublet peak emerges. However, as the substituents bonded to the P atoms in the phosphazene ring change, the chemical shifts (d) and coupling constants (J) vary from compound to compound (Table 1). This is necessary for the characterization of the compounds. Repetitive noise signals change the size and height of the peaks when the substitent change. Depending on the amount of substance dissolved in the NMR tube, the repetitive noise signals vary in size. Since the numbers on the original spectrum are small and not visible, the original numbers are written on the spectrum so that they can be clearly seen and read. Here noise peaks do not affect the characterization of the compounds. The original spectra of the compounds are present and we can prove all the peaks compounds. There is nothing contrary to scientific ethics in this article. The issues and information discussed in the publication are original. , 
 Dear Dr. Akbau015f, I very much appreciate your reply and explanation. Thank you. However, several experts have told me that NMR noise is random. And since this is a Fourier transformation, that means that any repetitive signal would be transformed into a single peak or sets of peaks, and not result in peaks repeated across the axis. But of course, you can take away any concerns , and you can prove that this data is original, as you claim, by posting the original FID files. Could you provide them here, please (e.g. a link to a Dropbox or Google Drive), so I can have these reviewed by several NMR specialists? I look forward to your response. , 
 #5 If you think that the repetitions are from equipment, you had to see it in many other spectra. Can you possibly cite the papers where similar repetitions can be found? Thank you. , 
 Dear Dr. Bik, In order to understand the subject, fid file of two compounds is given as an example. It is triplet and doublet peaks that are characteristic in showing that these substances are formed. Chemical shift values for these compounds are 26.58; 18.51 (PzIL4a), 26.73; 18.72 (PzIL5a) ppm. Coupling constants are 57.8, 56.2 Hz, respectively. These values are clearly seen in the table in the publication. As you can see in the fid file, the calculations cannot be read on the spectrum and cannot be published as such. In order to make it appear clearer, cleaner and darker, the spectrum was cleaned in the paint program. Photoshop was definitely not made. As we have already mentioned, the peaks that arise from the noise of the device and come from solvents or impurities have been corrected. No compound can be obtained in 100% purity. 98-99% purity is a very good purity. Many journals demand that the noise parts of spectra be corrected and made readable. A few of the original spectra of the compounds given the formulas were added to serve as examples. Scientists who are familiar with phosphorus nitrogen chemistry can easily analyze it. These scientists can find chemical shift values and coupling constants by calculating. These calculations will verify the coupling constants in Table 1. This is the main thing. The coupling constants are invariant quantities for each compound, such as the melting point. We obtain these materials in small quantities because they are expensive and very costly. We have no compounds now. However, if anyone wants, we can re-synthesize these substances within a certain period of time and show that they are original. A group that is an expert in phosphazene chemistry and has the appropriate laboratory can synthesize and repeat the substances if they wish. They can check their repeatability. Repeatability is very important in science. If there is any issue that does not satisfy you, report it again. Sincerely yours. https: drive.google.com drive folders 1F0QTpPx4UT8sWzdK9Ff0CnxVAMAhOngT?usp=sharing https: drive.google.com drive folders 1O2oFKQpi95eLkIQor-DdvTzCX_Udatro?usp=sharing , 
 #5 Please run a blank sample on the same instrument with the same condition again, and let us enjoy those beautiful repetitive noise together. , 
 #6 You are perfectly correct that a repetition on the frequency scale (as shown in the pictures) would be nothing short of a miracle (especially multiple times) and contrasting accepted knowledge regarding NMR (or points to an error in your Fourier transformation) The only way to disprove the accusations is by checking the original files from Dr. Akbau015f. , 
 Dear Hu00fcseyin Akbau015f; I am not NMR expert so I can not comment on those FID files. However, your following statement; As we have already mentioned, the peaks that arise from the noise of the device and come from solvents or impurities have been corrected. No compound can be obtained in 100% purity. 98-99% purity is a very good purity. Many journals demand that the noise parts of spectra be corrected and made readable. is very dangerous and makes all of your work that you presented in your scientific career up to now suspicious and potentially fabricated. No, journals do not demand such a correction. Please, in your next submission or in a conference presentation, mention that you removed impurities and solvent peaks using paint and then you will see whether this is normal or unethical. , 
 Dear Hu00fcseyin Akbau015f, thank you for sharing two FID files, which were analyzed by @Popher on Twitter, for which I am very grateful. However, it appears you shared the wrong files. The files you shared in #8 are for PzIL4a and PzIL5a. But I had concerns about PzIL1a, PzIL6a, and PzIL8a. So, assuming you uploaded the incorrect files by accident, would you mind sharing the FID files for those samples, please? , 
 The provided FID files, however, bring to light additional concerns. The spectrum that @Popher created from the FID file you provided for sample PzIL5a appears to show much more background than the spectrum shown for that sample in Figure S1. Here is a comparison of the two. Note the extra peaks around 21.5-22 and around 18.5. ![file] , 
 Update for remark #13: Twitter user @RogerGalligan pointed out some areas in the PzIL5a plot provided in Figure S1 that appear to look repetitive. I have marked them here below. Of note, the repetitive areas, marked here in dark red, green, and blue, occur only once in the redrawn-from-FID file, while they occur twice each in the published figure. These repeats happen to be the areas with the background peaks that are missing in the published plot. ![file] , 
 Oh wow, Dr. Bik is right. The provided FID data for PzIL5a do not match the figure in the supplement. If the provided data are correct, the figure has been manipulated and the paper must be at minimum corrected, if not retracted. I also do not see any indication in the paper or supplement that noise peaks have been  corrected . Neither is copy paste an ethical way to do any such  correction . ...  05 August 2020 Editoru2019s Note: Readers are alerted that the reliability of data presented in this manuscript is currently in question. Further editorial action may be taken as appropriate once the investigation into the concerns is complete and all parties have been given an opportunity to respond in full. That is a quick response from Scientific Reports - I m surprised. Hope they follow through , 
 Regarding the reply in #8:  In order to make it appear clearer, cleaner and darker, the spectrum was cleaned in the paint program. Photoshop was definitely not made. As we have already mentioned, the peaks that arise from the noise of the device and come from solvents or impurities have been corrected. No compound can be obtained in 100% purity. 98-99% purity is a very good purity. Many journals demand that the noise parts of spectra be corrected and made readable. It doesn t matter whether you used paint or Photoshop. You should clean your compounds in the lab, not the spectra on the computer. Of course there are always impurities, but it is not on you to decide how important they are. You can mark them with an asterisk and mention that they are impurities, then the reviewers and readers can decide if it is important or not. I can guarantee you that there is no reputable journal or reviewer that wants you to  correct the noise parts and make it readable . , 
 March 9 retraction. The notice can be found here: https: www.nature.com articles s41598-021-85542-6 From the Retraction Note:  The Editors have retracted this article. After publication concerns were raised that some of the NMR spectra contain irregularities. Specifically: * There are repetitions in the noise signal, which cannot be accounted for by the way the experiments were performed, in the 31P NMR spectrum for PzIL1a in Figure 1, the 31P NMR spectrum for PzIL8a in Figure S1 and the 31P NMR spectrum for PzIL6a in Figure S2. The Authors were not able to provide the original data for these spectra; * There are repetitions in the noise signal, which cannot be accounted for by the way the experiments were performed, in the 31P NMR spectrum for PzIL5a in Figure S1. The Authors provided original data for this spectrum, which showed that original data does not match Figure S1; * The Authors were able to provide original data for some of the spectra for samples PzIL2a, PzIL4a and PzIL5a. However, analysis of these data showed that the original spectra contained peaks that are not present in Figures S4 and S12. The Editors therefore no longer have confidence in the integrity of the data presented. Ahmet Karadau011f, Hu00fcseyin Akbau015f, Ali Destegu00fcl, u00c7iu011fdem u00c7aku0131rlar, and Yusuf Yerli disagree with the retraction. Zeynel Ku0131lu0131u00e7 and Fatih Sen did not respond to the correspondence about this retraction. , 
  Zeynel Ku0131lu0131u00e7 and Fatih Sen did not respond to the correspondence about this retraction It is disappointing that last author Fatih Sen, whom I understand to be the PI for this research group, was unavailable to defend the paper or explain the origins of its shortcomings. ,