Retraction: A New Sesquiterpene from Caragana intermediia and Its Anti‐Pyricularia oryzae P‐2b Activity

The following article from Chinese Journal of Chemistry , 'A New Sesquiterpene from Caragana intermediia and Its Anti–Pyricularia oryzae P–2b Activity' by Zhi–Hua Sun, Chang–Qi Hu, and Jin–Yi Wang, published online on May 15, 2008 in Wiley Online Library, and in print Volume 26 Issue 5, 2008, pages 831–834, has been retracted by agreement between the authors, the journal Editor in Chief, Prof. Guozhen Ji, and Wiley–VCH Verlag GmbH & Co. KGaA. The retraction has been agreed due to overlap between this article and the following article published in Chinese Chemical Letters , 'A new sesquiterpene from Caragana intermediia' by the same authors, Volume 18 Issue 11, 2007, pages 1379–1382.     

Retraction

Retraction: [Yun-Shan Zhou, Jia Wang, Xiao-Fang Lin, Qiuhua Jiang, Jian-Nan Zhu, A new Co(II)- coordination polymer: Photocatalytic studies and treatment values on mania by reducing the ErbB4 expression on the noradrenergic neurons, J. Chin. Chem. Soc. 2021 , 68, 1478–1486 ( https://onlinelibrary.wiley.com/doi/abs/10.1002/jccs.202100020 )]. The above article, published online on 24 March 2021 in Wiley Online Library ( wileyonlinelibrary.com ), has been retracted by agreement between the authors, the journal Editor-in-Chief, Jye-Shane Yang, the Chemical Society Located in Taipei, and Wiley-VCH GmbH, Weinheim. The retraction has been agreed following an investigation based on allegations raised by a third party and a request by the authors to retract. The authors stated that there are errors in the bioactivity experiments and that these results could not be reproduced. Thus, the conclusions of the article are not considered reliable.     

Retracted: Determination of scutellarin isomer,a predominant metabolite of scutellarin,in human plasma by HPLC/tandem mass spectrometry and its application to a pharmacokinetic study in Chinese healthy volunteers

Retraction: The following article from Biomedical Chromatography, “Determination of scutellarin isomer, a predominant metabolite of scutellarin, in human plasma by HPLC/tandem mass spectrometry and its application to the pharmacokinetic study in Chinese healthy volunteers” by Chun‐hua Xia, Yu‐qing Xiong, and Guang‐ji Wang, published online on 21 June 2007 in Wiley Interscience (www.interscience.wiley.com/journal/bmc), has been retracted at the authors' request.     

Comment on the paper “Extensive Theoretical Studies of a New Energetic Material: Tetrazino‐Tetrazine‐Tetraoxide (TTTO)” by Xinli Song,Jicun Li,Hua Hou,and Baoshan Wang

Discrepancies are noted in the implementation and presentation of the ccCA methodology in a previous publication, “Extensive Theoretical Studies of a New Energetic Material: Tetrazino‐tetrazine‐tetraoxide (TTTO)” by Xinli Song, Jicun Li, Hua Hou, and Baoshan Wang. The enthalpy of formation for TTTO has been re‐evaluated using the correct implementation of the ccCA methodology, demonstrating the results to be comparable to those of other ab initio composite methods. © 2012 Wiley Periodicals, Inc.     

Surface‐initiated ring‐opening polymerization of p‐dioxanone on Wang resin bead

Biodegradable poly(p‐dioxanone) (PPDO) was formed on Wang resin surface by surface‐initiated ring‐opening polymerization (SI‐ROP). The SI‐ROP of p‐dioxanone (PDO) was achieved by heating a mixture of Tin(II) bis(2‐ethylhexanoate) [Sn(Oct)₂], hydroxyl functionalized Wang resin, and PDO in anhydrous toluene at 80 °C. The resultant polymer‐grafted Wang resin (Wang‐g‐PPDO) was characterized by fourier transform infrared (FTIR) spectroscopy, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), optical microscopy (OM), and field‐emission scanning electron microscopy (FE‐SEM). The FTIR spectra of Wang‐g‐PPDO show peak characteristic of PPDO at 2943 cm^?1 (? C? H stretch), at 1741 cm^?1 (? C?O stretch), and 1136 cm^?1 (C? O? C stretch) indicating the formation of ester linkage between PPDO and hydroxyl terminated Wang resin. The DSC thermogram show melting peak corresponding to PPDO polymer on Wang resin surface. Thermogravimetric investigation shows increase in PPDO content on the Wang resin surface in terms of percentage of weight loss with increase in reaction time. The OM and SEM photographs clearly show the formation of PPDO polymer on the Wang resin surface without altering the spherical nature of Wang resin bead. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 1178–1184, 2008     

Retracted: Nanobubbles influence on BSA adsorption on mica surface

Retraction: The following article from the Surface and Interface Anlysis, 'Nanobubbles influence on BSA adsorption on mica surface' by Wu ZH, Zhang XH, Zhang XD, Li G, Sun J, Zhang Y, Li M and Hu J, published online on 1 September 2005 in Wiley InterScience ( www.interscience.com ) and in print Volume 37 Issue 10 pages 797‐801, 2005, has been retracted by agreement between the authors, the journal's Editor‐in‐Chief Professor John F. Watts and John Wiley & Sons, Ltd. The retraction has been agreed due to the article being subsequently published in Volume 38 Issue 6, pages 990‐995 of the journal as part of a Special Issue entitled 'Chinese‐German Forum on Fundamentals and Technological Perspectives of Nanoscience 26‐30 September 2004, Beijing, China.'     

Retracted: Synthesis,characterization and reactivity towards first‐row d‐transition metals and biological significance of new pyridinyl derived N‐substituted sulfonamides

Retraction: The following article from the Journal of Applied Organometallic Chemistry , ‘Synthesis, characterization and reactivity towards first‐row d‐transition metals and biological significance of new pyridinyl derived N‐substituted sulfonamides’ by Muhammad M. Naseer and Zahid H. Chohan, published online on 20 July 2007 in Wiley Interscience ( www3.interscience.wiley.com ), has been retracted by agreement between the authors, the journal Editor in Chief, Peter J. Craig and John Wiley & Sons, Ltd. The retraction has been agreed at the authors' request.     

Theoretical study of the internal elimination reactions of xanthate precursors

The gas‐phase internal elimination (E_i) reaction of ethyl xanthate (CH₃‐CH₂‐S‐CS‐O‐CH₃) has been investigated by means of Hartree–Fock, second‐order Møller–Plesset, and density functional theory (DFT) using the Becke three‐parameter Lee–Yang–Parr (B3LYP) functional and the modified Perdew–Wang one‐parameter model for kinetics (MPW1K). Considerable differences between the ground‐ and transition‐state geometries and the calculated activation energies are observed from one approach to the other, which justifies first a careful calibration of the methods against the results of benchmark CCSD(T) calculations. Compared with these, DFT calculations along with the MPW1K functional are found to be an appropriate choice for describing the E_i reaction of xanthate precursors. The precursor conformation and the transition states involved in the internal conversion of xanthate precursors of cyano derivatives of ethylene, and of cis‐ and trans‐stilbene, are then characterized in detail by means of this functional. © 2003 Wiley Periodicals, Inc. J Comput Chem 24: 2023–2031, 2003     

Elaboration of well‐defined Rasta resins and their use as supported catalytic systems for atom transfer radical polymerization

New supported catalytic systems based on the immobilization of a ligand onto supported (co)polymers were prepared, allowing copper immobilization onto a solid support during the atom transfer radical polymerization (ATRP) of methyl methacrylate (MMA). These supported catalysts were elaborated by the ATRP of 2‐vinyl‐4,4‐dimethyl‐5‐oxazolone and/or styrene onto a Wang resin initiator. Two different approaches were used, involving well‐defined architectures synthesized by ATRP. First, a supported electrophilic homopolymer [Wang‐g‐poly(2‐vinyl‐4,4‐dimethyl‐5‐oxazolone)] was synthesized to obtain an azlactone ring at each repetitive unit, and a supported statistical copolymer [Wang‐g‐poly(2‐vinyl‐4,4‐dimethyl‐5‐oxazolone‐stat‐styrene)] was synthesized to introduce a distance between the azlactone rings. The azlactone‐based (co)polymers were then modified by a reaction with N,N,N′,N′‐tetraethyldiethylenetriamine (TEDETA) to create supported complexing sites for copper bromide. The ATRP of MMA was studied with these supported ligands, and a first‐order kinetic plot was obtained, but high polydispersity indices of the obtained poly(methyl methacrylate) were observed (polydispersity index > 2). On the other hand, the supported ATRP of styrene was performed, followed by the nucleophilic substitution of bromine by TEDETA (Wang‐g‐polystyrene–N,N,N′,N′‐tetraethyldiethylenetriamine) at the chain end of the grafted polystyrene chains. This strategy led the ligand away from the core bead, depending on the length of the polystyrene block (number‐average molecular weight determined by size exclusion chromatography = 1100–2250 g/mol). These supported complexes mediated a controlled polymerization of MMA, yielding polymers with controlled molar masses and low polydispersity indices. Moreover, after the polymerization, 96% of the initial copper was kept in the beads. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 5316–5328, 2006     

Structural relaxation of glass-forming polymers based on an equation for configurational entropy, 4. Structural relaxation in styrene-acrylonitrile copolymer

The structural relaxation process in styrene-acrylonitrile copolymer has been characterized by means of differential scanning calorimetry (DSC) experiments. The results in the form of heat capacity, c_p(T), curves are analyzed using a model for the evolution of the configurational entropy during the process recently proposed by the authors.^11,12 The model simulation allows one to determine the enthalpy (or entropy) structural relaxation times and the β parameter of the Kohlrausch-Williams-Watts equation characterizing the width of the distribution of relaxation times. This material parameters are compared with their analogues determined from the dielectric and dynamic-mechanical relaxation processes. © 1997 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 35: 2201–2217, 1997     

RETRACTED ARTICLE: Four Ln-coordination polymers: synthesis,crystal structure,fluorescent sensing of nitrobenzene and Tb3+, and catalytic properties

We, the Editors and Publisher of Journal of Coordination Chemistry, have retracted the following article:

Yu-Yuan Tang, Shuang Chen, Cui-Juan Wang, Zi-Xin Zhu & Dong-Ning Liu. Four Ln-coordination polymers: synthesis, crystal structure, fluorescent sensing of nitrobenzene and Tb³⁺, and catalytic properties. Journal of Coordination Chemistry 71.19 (2018) 3207-3221. DOI: 10.1080/00958972.2018.1517257

Since publication it has come to our attention that there are duplications of data for the europium compound (compound 1) presented in the above 2018 article and the terbium compound presented in the below 2017 article.

Yu-Yuan Tang, Cui-Juan Wang, Shuang Chen & Hai-Yu Dai. A terbium(III) organic framework as a fluorescent probe for selectively sensing of organic small molecules and metal ions especially nitrobenzene and Fe³⁺. Journal of Coordination Chemistry 70.24 (2017) 3996-4007. DOI:10.1080/00958972.2017.1413490

The cell constants presented in the two papers for the two different compounds are identical, including the esds for the lengths of the axes and the absence of esds on the bond angles. Examination of the submitted CIFs for the two compounds showed identical information plus additional data, including the crystal dimensions. The deposited hkl files for the two different compounds are identical, indicating that the same crystal data was used for the two compounds.

Following COPE guidelines, Taylor & Francis has contacted the authors as well as their affiliated institution with a request for clarification, however the explanation we received has not been satisfactory. As such, we are retracting both papers as it is clear data has been duplicated between the two structures. The authors were informed of this decision and have since agreed to the retraction.

We have been informed in our decision-making by our policy on publishing ethics and integrity and the COPE guidelines on retractions.

The retracted articles will remain online to maintain the scholarly record, but they will be digitally watermarked on each page as “Retracted”.     

Enantiopure phosphacymantrene‐2‐carboxaldehyde and some of its derivatives

The resolution of η⁵(2‐formyl‐3,4‐dimethylphospholyl)(triphenylphosphine)‐manganesedicarbonyl 1 has been carried out by chromatography of the acetals derived from (S,S)‐1,2‐diphenylethane‐1,2‐diol. The enantiopure 2‐diphenylphosphinomethyl 4 and diphenylmethylimino 5 derivatives have been prepared from 1 . © 2005 Wiley Periodicals, Inc. Heteroatom Chem 16:458–460, 2005; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20130     

Semiempirical treatment of electrostatic potentials and partial charges in combined quantum mechanical and molecular mechanical approaches

A semiempirical treatment of electrostatic potentials and partial charges is presented. These are the basic components needed for the evaluation of electrostatic interaction energies in combined quantum mechanical and molecular mechanical approaches. The procedure to compute electrostatic potentials uses AM1 and MNDO wave functions and is based on one previously suggested by Ford and Wang. It retains the NDDO approximation and is thus both easy to implement and computationally efficient. Partial atomic charges are derived from a semiempirical charge equilibration model, which is based on the principle of electronegativity equalization. Large sets of ab initio restricted Hartee-Fock (RHF/6-31G*) reference data have been used to calibrate the semiempirical models. Applying the final parameters (C, H, N, O), the ab initio electrostatic potentials are reproduced with an average accuracy of 20% (AM1) and 25% (MNDO), respectively, and the ab initio potential derived charges normally to within 0.1 e. In most cases our parameterized models are more accurate than the much more expensive quasi ab initio techniques, which employ deorthogonalized semiempirical wave functions and have generally been preferred in previous applications. © 1996 John Wiley & Sons, Inc.     

Withdrawn: Analysis of thermal parameters and factors acting on thermal conduction of low‐k films

This paper appeared in the October issue, occupying pp. 1362‐1366. It was a duplicate of SIA.2880, which appears on pp. 1328‐1332 of the same issue. It has therefore been withdrawn from Wiley InterScience. The publisher apologises to the authors for the error. Copyright © 2008 John Wiley & Sons, Ltd.     

Retracted: Determination of dextra–methylprednisolone conjugate with glycine linker in rat plasma and liver by high‐performance liquid chromatography and its application in pharmacokinetics

The following article from Biomedical Chromatography, Determination of dextra‐methylprednisolone conjugate with glycine linker in rat plasma and liver by high‐performance liquid chromatography and its application in pharmacokinetics by Shuang‐Qing Zhang and Reza Mehvar, published online on June 1^st 2009 in Wiley InterScience ( www.interscience.wiley.com ), has been retracted by agreement between the journal Editor in Chief, Dr Chang Kee Lim and John Wiley and Sons, Ltd. The retraction has been agreed as the research article was submitted without Dr. Mehvar's knowledge or consent.     

Microwave‐assisted from synthesis of 2‐arylamino‐2‐imidazolines on a solid support

An efficient synthesis of 2‐arylamino‐2‐imidazolines from dimethyl N‐aryldithioimidocarbonates and ethylenediamine on solid support under microwave irradiation has been developed. The reaction time has been reduced from hours to minutes with improved yields as compared to conventional heating. Their piperidin‐4‐ylmethyl and morpholin‐4‐ylmethyl derivatives were synthesized by treatment with formaldehyde and piperidine or morpholine. © 2005 Wiley Periodicals, Inc. Heteroatom Chem 16:142–222, 2005; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20081     

2,4,6‐Tri‐tert‐butylphenyl and 2,4‐di‐tert‐butyl‐6‐methylphenyl groups: Look similar,react differently

The crystal structures of molecules with two phosphaalkene groups have been determined. Differences in the stabilization of the PC π‐bond by the 2,4,6‐tri‐tert‐butylphenyl and 2,4‐di‐tert‐butyl‐6‐methylphenyl groups were observed. It has been found that lithium supermesityl(trimethylsilyl)phosphide could be a very efficient base to remove a proton from acetonitrile.© 2002 Wiley Periodicals, Inc. Heteroatom Chem 13:662–666, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.10083