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Experimental details and characterisation required for journal articles

Guidance on reporting experimental procedures and compound characterisation.

We believe that where possible, all data associated with the research in a manuscript should be Findable, Accessible, Interoperable and Reusable (FAIR), enabling other researchers to replicate and build on that research. We strongly encourage authors to deposit the data underpinning their research in appropriate repositories and make it as openly accessible as possible.

For all submissions to our journals, any data required to understand and verify the research in an article must be made available on submission. To comply, we suggest authors deposit their data in an appropriate repository. Where this isn’t possible, we ask authors to include the data as part of the article Supplementary Information. If necessary data are not made available, authors may be requested to provide these as part of the peer-review process, or in light of any post-publication concerns.

Please see our data sharing guidance and policy for more details on specific data types and recommended repositories.

Some journals may also have additional subject requirements for both sharing and/or publishing supporting data, so please ensure you check the journal-specific guidelines.

On this page

General guidance

These experimental reporting requirements apply to both new compounds and known compounds prepared by a new or modified method.

It is the authors’ responsibility to provide descriptions of the experiments in enough detail to enable other skilled researchers to accurately reproduce the work.

Experimental procedures, compound characterization data, research materials necessary to enable the reproduction of an experiment and references to the associated literature should be provided in the experimental section of the manuscript.

Standard techniques and methods used throughout the work should be stated at the beginning of the experimental section; descriptions of these are not needed.

For known compounds synthesised via a literature procedure, authors should provide a reference to previously published characterization data.

Sources of starting materials obtained need not be identified unless the compound is not widely available, or the source is critical for the experimental result. Only non-standard apparatus should be described and commercially available instruments can be referred to by their stock numbers.

The accuracy of primary measurements should be stated. Figures should include error bars where appropriate, and results should be accompanied by an analysis of experimental uncertainty. Care should be taken to report the correct number of significant figures throughout the manuscript.

Any unusual hazards associated with the chemicals, procedures or equipment should be clearly identified.

For studies that involve the use of live animals or human subjects please refer to our Human and Animal Welfare policy.

Please see the sections below for detailed information about how to present specific types of data.

Presentation of experimental data

Data associated with particular compounds should be listed after the name of the compound concerned, following the description of its preparation. If comparison is to be made with literature values, these should be quoted in parentheses - for example, mp 157 °C (from chloroform) (lit.,19 156 °C), or νmax/cm-1 2020 and 1592 (lit.,24 2015 and 1600).

The suggested order in which the most commonly encountered data for a new compound should be cited follows:

  • Yield
  • Melting point
  • Optical rotation
  • Refractive index
  • Elemental analysis
  • UV absorptions
  • IR absorptions
  • NMR spectrum
  • Mass spectrum

You can find more information about each of these below:

The following information is a guide to the presentation of experimental data, including appropriate formats for citation.

Yield

Yield should be presented in parentheses after the compound name (or its equivalent). Weight and percentage should be separated by a comma – for example, the lactone (7.1 g, 56%).

Melting point

The melting point should be presented in the form mp 75°C (from EtOH) - that is, the crystallisation solvent in parentheses. If an identical mixed melting point is to be recorded, the form mp and mixed mp 75°C is appropriate.

Optical rotation

The units should be stated in the preamble to the Experimental section – for example, [α]D values are given in 10−1 deg cm2 g−1. This should be shown in the form [α]D 22–22.5 (c 0.95 in EtOH) – that is, concentration and solvent in parentheses.

Refractive index

Given in the form nD22 1.653.

Elemental analysis

For the presentation of elemental analyses, both forms (Found: C, 63.1; H, 5.4. C13H13NO4 requires C, 63.2; H, 5.3%) and (Found: C, 62.95; H, 5.4. Calc. for C13H13NO4: C, 63.2; H, 5.3%) are acceptable. Analyses are normally quoted to the nearest 0.1%, but a 5 in the second place of decimals is retained.

If a molecular weight is to be included, the appropriate form is: [Found: C, 63.1; H, 5.4%; M (mass spectrum), 352 (or simply M+, 352). C13H13NO4 requires C, 63.2; H, 5.3%; M, 352].

We encourage authors to provide instrumental details and the chromatograms of the performed measurements in the Supplementary Information where possible.

UV absorptions

These should be given in the form λmax(EtOH)/nm 228 (ε/dm3 mol-1 cm-1 40 900), 262 (19 200) and 302 (11 500). Inflections and shoulders are specified as 228infl or 262sh. Alternatively the following form may be used: λmax (EtOH)/nm 228, 262 and 302 (ε/dm3 mol-1 cm-1 40 900, 19 200 and 11 500); log ε may be quoted instead of ε.

IR absorptions

IR absorption should be presented as follows: νmax/cm-1 3460 and 3330 (NH), 2200 (conj. CN), 1650 (CO) and 1620 (CN). The type of signal (s, w, vs, br) can be indicated by appended letters (for example 1760vs).

NMR data

For all NMR spectra δ values should be used, with the nucleus indicated by subscript if necessary (for example, δH, δC). A statement specifying the units of the coupling constants should be given in the preamble to the Experimental section – for example, J  values are given in Hz. Instrument frequency, solvent, and standard should be specified. For example: δH(100 MHz; CDCl3; Me4Si) 2.3 (3 H, s, Me), 2.5 (3 H, s, COMe), 3.16 (3 H, s, NMe) and 7.3–7.6 (5 H, m, Ph).

A broad signal may be denoted by br, such as 2.43 (1 H, br s, NH). Order of citation in parentheses: (i) number of equivalent nuclei (by integration), (ii) multiplicity (s, d, t, q), (iii) coupling constant – for example, J 1,2 2, J AB 4, (iv) assignment; italicisation can be used to specify the nuclei concerned (for example, CH3CH2). The proton attached to C-6 may be designated C(6)H or 6-H; the methyl attached to C-6, 6-Me or C(6)Me.

Mutually coupled protons in 1H NMR spectra should be quoted with precisely matching J  values, in order to assist thorough interpretation. In instances of any ambiguities when taking readings from computer printouts, mean J  values should be quoted, rounded to the nearest decimal point.

Mass spectrometry data

Mass spectrometry data should be given in the form: m/z 183 (M+, 41%), 168 (38), 154 (9), 138 (31) etc. The molecular ion may be specified as shown if desired. Relative intensities should be shown in parentheses (% only included once). Other assignments may be included in the form m/z 152 (33, M − CH3CONH2). Metastable peaks may be listed as: M* 160 (189→174), 147 (176→161), etc. The type of spectrum (field desorption, electron impact, etc.) should be indicated. Exact masses quoted for identification purposes should be accurate to within 5 ppm (EI and CI) or 10 ppm (FAB or LSIMS).

Post-acquisition processing of data

Authors might be asked during peer review to provide the original unprocessed data to the editors/reviewers of the journal.

All image acquisition and processing tools (including their settings) should be clearly stated in the manuscript. The amount of post-acquisition processing of data should be kept to a minimum. Any type of alteration such as image processing, cropping and groupings should be clearly stated in the figure caption and the Supplementary Information (SI) - clearly describing the process of alteration. Data manipulation (for example, normalisation or handling of missing values) should be noted.

Image processing changes should be applied to the entire image as well as all other images it is compared to. Processed images should still represent all the original data (with no data missing) and touch-up tools should be avoided.

Genuine and relevant signals in spectra should not be lost due to image enhancement.

Microscopy images of cells from multiple fields should not be compared but shown as single images (at least as part of the deposited data or in the SI).

Data citation

For author-generated datasets that are directly associated with the article, we encourage authors to add data citations as bibliographic references within the article and the Data Availability Statement (DAS). Within the DAS, the citation should be given alongside information on datasets associated with the study and where to find them.

For datasets associated with previous studies, we encourage authors to add data citations as bibliographic references within the main text as they are mentioned. Data citation is encouraged as an alternative to informal references or mentions of local identifiers.

Suggested reference format for data citations:

[A. Name, B. Name and C. Name], [Name of repository / type of dataset], [Deposition number], [Year], [DOI, or URL if not available, of the dataset].

An example:

P. Cui, D. P. McMahon, P. R. Spackman, B. M. Alston, M. A. Little, G. M. Day and A. I. Cooper, 2019, CCDC Experimental Crystal Structure Determination: 1915306, DOI: 10.5517/ccdc.csd.cc22912j

Please also refer to the guidelines from the relevant repository on which information to provide in a citation.

Human and animal welfare

When a study involves the use of live animal subjects, authors should adhere to the ‘Animal Research: Reporting In Vivo Experiments’ . When a study involves the use of human subjects, authors should adhere to the general principles set out in the .

Authors must include in the 'methods/experimental' section of the manuscript a statement that all experiments were performed in compliance with the relevant guidelines. The statement must name the institutional/local ethics committee that has approved the study, and where possible the approval or case number should be provided. Details of all guidelines followed should be provided. A statement regarding informed consent is required for all studies involving human subjects. Reviewers may be asked to comment specifically on any cases in which concerns arise.

For studies involving the use of animal subjects, authors are encouraged to make the completed ARRIVE 2.0 checklist available during peer review, for example by sharing it as part of the ESI or citing the deposited item.

The journals’ editorial teams reserve the right to request additional information in relation to experiments on vertebrates or higher invertebrates as necessary for the evaluation of the manuscript e.g., in the context of appropriate animal welfare or studies that involve death as an experimental endpoint.

Batteries

Authors and referees should note the following guidelines for articles reporting electrochemical data and setup of batteries. It is the authors’ responsibility to ensure that the following information is provided in the main manuscript or Supplementary Information as appropriate.

The setup used for electrochemical testing should be clearly specified in the Experimental Information. For example, full or half cells, reference electrode (if used), testing temperature, etc.

When reporting electrochemical performance data, the authors should clearly state how many experimental runs these data are based on. The electrochemical performance value calculations should be clearly explained (including information on using charging or discharging values). All electrochemical data should be reported to an appropriate number of significant figures, along with standard deviation and error bars on graphs.

When reporting electrode performance values, the thickness of the electrode and the mass percentage of all electrode components (active material, additive, binder, etc.), the total mass of the electrode, and the geometric area of the electrode should be provided.

When reporting device-level performance values, the mass percentage of all battery components (active material, additive, binder, casing, current collector, electrolyte, separator, etc.), the total mass of the battery, and the geometric area of the electrode should be reported.

The mass percent and theoretical capacity of the active material should be provided if the theoretical capacity of the studied material is known. The theoretical capacity should be used to calculate C-rate. Alternatively, a rigorous use of A g-1 is recommended.

Pre-cycling and/or first cycle data should be reported.

Calculations of battery capacity should report the capacity obtained (in mAh g-1; if appropriate, volumetric values can be added in the unit of mAh cm-3) with the cycling rate and at what cycle number this capacity was obtained clearly stated. Average capacities for ≥3 cells with standard deviation are preferred.

Biomolecules

It is the authors’ responsibility to provide rigorous evidence for the identity and purity of the biomolecules (for example, enzymes, proteins, DNA/RNA, oligosaccharides, oligonucleotides) described.

The identity of the biomolecule should be substantiated by employing at least one appropriate method, which may include one or more of the following:

Mass spectrometry

  • LC-MS
  • Sequencing data (for proteins and oligonucleotides)
  • High field 1H or 13C NMR
  • X-Ray crystallography

The purity should be established by one or more of the following

  • HPLC
  • Gel electrophoresis
  • LC-MS
  • Capillary electrophoresis
  • High field 1H or 13C NMR

Sequence verification should also be carried out for nucleic acids in molecular biology, including all mutants; for new protein or gene sequences, the entire sequence should be provided. For organic synthesis involving DNA, RNA oligonucleotides, their derivatives or mimics, purity should be established using HPLC and mass spectrometry as a minimum.

Provide usual organic chemistry analytical requirements for the novel monomer (see Organic compounds). However, it is not necessary to provide this level of characterisation for the oligonucleotide into which the novel monomer is incorporated.

Provide sufficient detail to identify the species being used. Specific information on antibodies is essential. Commercial sources and, if new antibodies are generated, full experimental details such as immunogen/phage, species, protocols for mAb-) should be given. We strongly recommend authors use unique Resource Identifiers for model organisms, antibodies, and tools, and publish them with full descriptions.

Present scatter plots of data, sensitivity, and specificity values with confidence intervals and results of receiver operating characteristic curve analysis. If a marker is already routinely used for that disease, comparison with that marker should be included.

Catalysts

Where the screening of new catalysts is reported, authors should provide a mass balance for all reactions (using, for example, an internal standard in their analysis technique). Recycling efficiencies should be based on reaction rates measurements and not product yield as a function of cycle. It is highly desirable to report the reaction rate for the catalysts as turnover frequency or mass-specific activity or, for heterogeneous catalysts, as surface-specific activity.

Characterisation of compounds and materials

It is the responsibility of authors to provide fully convincing evidence for the homogeneity and identity of all compounds whose preparations they describe. Evidence of both purity and identity is required to establish that the properties and constants reported are those of a compound as claimed.

Reviewers will assess the evidence in support of the homogeneity and structure of all new compounds. No hard and fast rules can be laid down to cover all types of compound, but evidence for the unequivocal identification of new compounds should, wherever possible, include good elemental analytical data – an accurate mass measurement of a molecular ion does not provide evidence of purity of a compound and should be accompanied by independent evidence of homogeneity.

Where elemental analytical data cannot be obtained, appropriate evidence that is convincing to an expert in the field may be acceptable. Normally, for diamagnetic compounds this entails, at a minimum, a high resolution mass spectrometry measurement along with assigned 1H and/or 13C NMR spectra devoid of visible impurities.

Spectroscopic information necessary for the assignment of structure should be given. How complete this information should be depends upon the circumstances; the structure of a compound obtained from an unusual reaction or isolated from a natural source should be supported by stronger evidence than one that was produced by a standard reaction from a precursor of undisputed structure.

Particular care should be taken in supporting the assignments of stereochemistry (both relative and absolute) of chiral compounds reported, for example by one of the following:

  • NMR spectroscopy
  • X-Ray crystallography
  • Polarimetry
  • Correlation with known compounds of undisputed configuration

In cases where mixtures of isomers are generated (for example, E-Z isomers, enantiomers, diastereoisomers), the constitution of the mixture should usually be established using appropriate analytical techniques (for example, NMR spectroscopy, GC, HPLC) and reported in an unambiguous fashion.

For an asymmetric reaction in which an enantiomeric mixture is prepared, the direct measurement of the enantiomer ratio expressed as the enantiomeric excess (ee) is recommended, and is preferred to less reliable polarimetry methods.

If a compound is new more detailed characterisation will be required. A compound is considered to be new if:

  • it has not been prepared before
  • it has been prepared before but not adequately purified
  • it has been purified but not adequately characterised
  • it has been assigned an erroneous composition previously
  • it is a natural product isolated or synthesized for the first time

We encourage authors reporting various compounds or compound libraries to apply the FAIR principles and include a summary file of these compounds as part of the submission. This file should be deposited in an appropriate repository or be provided as part of the Supplementary Information, and should adhere to the following:

  • format - CSV (*.csv), TSV (*.tsv) or SDF (*.sdf)
  • for chemical structures - relevant headers including SMILES, InChI and InChIKey
  • for chemical names - Name and Synonym
  • for other comments - such data, metadata, etc

These instructions are based on (E.L. Schymanski & E.E. Bolton, Journal of Cheminformatics, 2021, 13, 50).

We recommend that authors follow the guidelines for the nomenclature of new radiolabelled compounds, as laid out in (C.H.H., G.A.D. et al., Nuclear Medicine and Biology, 2017, 55, v – xi).

Computational studies and modelling

Authors should provide sufficient information to enable readers to reproduce any computational results. If software was used for calculations and is generally available, it should be properly cited in the references. References to the methods upon which the software is based should also be provided.

Equations, data, geometric parameters/coordinates, or other numerical parameters essential to the reproduction of the computational results (or adequate references when available in the open literature) should be provided. Authors who report the results of electronic structure calculations in relative energies should also include the absolute energies obtained directly from the computational output files. These may be deposited in an appropriate repository and cited, or provided in the Supplementary Information (SI).

We ask that the following information be provided where possible:

  • As a minimum, papers reporting QM work should include the atomic coordinates, energies, and number of imaginary frequencies for all computed stationary points
  • The level of theory used for computations should be mentioned in the text, and/or in the caption of the first figure that reports the results of those computations
  • Where calculations are performed with density functional theory, the integration grid used for the calculations should be specified
  • All relevant total energies (potential energies, enthalpies, Gibbs free energies, etc.) should be reported for each computed species.
  • For transition states (TSs), the magnitude of the frequency of the imaginary vibrational mode may also be reported
  • For intrinsic reaction coordinate (IRC) calculations, any shoulders in the IRC plots should be noted. If IRC calculations reveal that a TS corresponded to a reaction pathway different from that suggested by simple animation of its imaginary mode, then the IRC results (plots and details of reactants/products) should be deposited in an appropriate repository and cited
  • Where computational work is included as part of a synthetic study, full details of any theoretical characterization (for example, computational NMR or VCD) of products and/or important synthetic intermediates should be documented

We also strongly encourage xyz, .mol2 or .pdb files for coordinates to be shared via deposition in an appropriate repository.

Electrophoretic gels and blots

It is the responsibility of the authors to provide the raw data for all electrophoretic gel and blot data, ensuring sufficient evidence to support their conclusions.

All Western blot and other electrophoresis data should be supported by the underlying raw images. The image of the full gel and blot, uncropped and unprocessed, should be made available on submission. We suggest authors deposit their data in an appropriate repository. Where this isn’t possible, we ask authors to include the data as part of the Supplementary Information. All samples and controls used for a comparative analysis should be run on the same gel or blot.

When illustrating the result, any cropping or rearrangement of lanes within an image should be stated in the figure legend and with lane boundaries clearly delineated. Alterations should be kept to a minimum required for clarity.

Each image should be appropriately labelled, with the closest molecular mass markers and lanes labelled. All details should be visible; over or underexposed gels and blots are not acceptable. Authors should be able to provide raw data for all replicate experiments upon request.

Fluorescence sensors

Studies on fluorescence sensor systems should include titrations covering a full range of analyte concentration, from the absence of analyte to a stoichiometric excess, taking the following factors into account:

  • If the analyte shows significant absorption at the excitation or emission frequencies corrections should be carried out for Inner Filter Effects (IFEs). (note: fluorescence probes where the response mechanism is based on the Inner Filter Effect are not suitable for publication in NJC)
  • A plateau should be observed at high analyte concentrations for the intensity vs. concentration plot when the sensing mechanism is based on association
  • Calculated Limits of Detection (LoD) should be supported by experimental data at similar concentrations
  • The intensity vs. concentration relationship should be fitted using suitable software. The Benesi-Hildebrand linearization method for the determination of the association constant should not be used without extensive consideration of the limitations that arise from the method’s assumptions (see Chemical Society Reviews Tutorial 10.1039/C0CS00062K for further details.)

Plots reporting the Stern-Volmer relationship (I°/I vs. concentration; the same should be valid for its reciprocal I/I°) should show an intercept of 1. Significant variation from this is not acceptable.

The Stern-Volmer relationship should be justified by reference to an appropriate quenching mechanism, e.g. dynamic quenching should show a linear relationship, while static quenching can present an upward curvature for relatively high association constants (see Chemical Society Reviews Tutorial 10.1039/D1CS00422K for further discussion)

The performance of all sensor systems should be compared to the current state-of-the-art sensors for the same analyte, with any differences in requirements (e.g. solvent system) clearly stated; a suitable (and justified) set of interferences should also be tested and discussed.

Inorganic and organometallic compounds

A new chemical substance (molecule or extended solid) should have a homogeneous composition and structure. Where the compound is molecular, authors should provide data to unequivocally establish its homogeneity, purity and identification as described above.

In general, this should include elemental analyses or a justification for the omission of this data.

This is particularly important for NMR silent paramagnetic compounds where NMR data tends to be less useful in establishing purity. In some instances an assigned 1H NMR spectrum of a paramagnetic compound that is demonstrably devoid of impurities may be acceptable.

It may be possible to substitute elemental analyses with high-resolution mass spectrometric molecular weights. This is appropriate, for example, with trivial derivatives of thoroughly characterised substances or routine synthetic intermediates. In all cases, relevant spectroscopic data (NMR, IR, UV-vis, etc.) should be provided in tabulated form or as reproduced spectra. These may be deposited in an appropriate repository and cited, or provided in the Supplementary Information (SI). However, it should be noted that, in general, mass spectrometric and spectroscopic data do not constitute proof of purity, and, in the absence of elemental analyses, additional evidence of purity should be provided (melting points, PXRD data, etc.).

Where the compound is an extended solid, it is important to unequivocally establish the chemical structure and bulk composition. Single crystal X-ray diffraction does not determine the bulk structure. Reviewers will normally look to see evidence of bulk homogeneity. A fully indexed powder diffraction pattern that agrees with single crystal data may be used as evidence of a bulk homogeneous structure, and chemical analysis may be used to establish purity and homogeneous composition.

Detailed information on the reporting requirements for X-ray crystallography, including small molecule single crystal data and powder diffraction data is available in the section on X-ray crystallography.

Macromolecular structure and sequence data

Novel macromolecular structures and newly reported nucleic acid or protein sequences and microarray data should be deposited in appropriate repositories. It is the responsibility of the authors to provide relevant accession numbers prior to publication.

A Data Availability Statement with suitable links to the deposited data should be included. Please see our Data Sharing policy for more details. For high-throughput studies, we encourage authors to refer to Minimum Information Standards as determined and maintained by the relevant communities. For further details see:

  • Minimum information standard - Wikipedia
  • Minimum Information for Biological and Biomedical Investigations - FAIRsharing Information Resource

The following should be supplied for macromolecular X-ray structures:

  • PDB header information
  • Rmerge, completeness, multiplicity and I/sigma(I) - both overall and in the outer resolution shell - for data, and
  • Rcryst, Rfree and the bond and angle deviations for coordinates
  • a Ramachandran plot, and preferably
  • real space R-factor

For NMR structures equivalent data plus resonance assignments should be supplied - number of restraints (NOEs and J-couplings), RMS restraint deviation, etc, plus resonance assignments should be supplied.

All the above information should be included as summary data tables in the manuscript or may be deposited in an appropriate repository and cited, or provided in the Supplementary Information.

Magnetic measurements

If data from magnetic measurements are presented, the authors should provide a thorough description of the experimental details pertaining to how the sample was measured. If the data have been corrected for sample or sample holder diamagnetism, the diamagnetic correction term should be provided and the manner in which it was determined should be stated.

Any fit of magnetic data (for example, χ(T), χ(1/T), χT(T), μ(T), M(H), etc.) to an analytical expression should be accompanied by the Hamiltonian from which the analytical expression is derived, the analytical expression itself, and the fitting parameters. If the expression is lengthy, it may be deposited in an appropriate repository and cited, or relegated to the Supplementary Information to conserve space. When an exchange coupling constant (J) is quoted in the abstract, the form of the Hamiltonian should also be included in the abstract.

Nanomaterials

For nanomaterials (such as quantum dots, nanoparticles, nanotubes, nanowires), it is the authors’ responsibility not only to provide a detailed characterisation of individual components (see Inorganic and organometallic compounds) but also a comprehensive characterisation of the bulk composition. Characterisation of the bulk sample could require determination of the chemical composition and size distribution over large portions of the sample.

All nanoparticulate materials should have been purified from synthesis by-products and residual parent compounds, ions etc. If they are to be applied in dispersed form (for example, as a nanoparticulate drug carrier), sufficient data on the dispersion state should be provided (for example, by dynamic light scattering, centrifugal analysis, nanoparticle tracking analysis).

SEM or TEM images for hybrid inorganic-organic nanoparticles should be provided in at least three different levels of magnification. Bar scales should be clearly visible. Images may be deposited in an appropriate repository and cited, or provided in the Supplementary Information (SI).

Organic compounds

It is the responsibility of the authors to provide unequivocal support for the purity and assigned structure of all compounds using a combination of the following characterisation techniques.

Elemental analysis is recommended to confirm sample purity and corroborate isomeric purity. We encourage authors to provide instrumental details and the chromatograms of the performed measurements in the Supplementary Information where possible. Authors are also requested to provide 1H,13C NMR spectra and/or GC/HPLC traces if satisfactory elemental analysis cannot be obtained.

For libraries of compounds, HPLC traces should be submitted as proof of purity. The determination of enantiomeric excess of nonracemic, chiral substances should be supported with either GC/HPLC traces with retention times for both enantiomers and separation conditions (that is, chiral support, solvent and flow rate) or for Mosher Ester/Chiral Shift Reagent analysis, copies of the spectra.

Important physical properties, for example, boiling or melting point, specific rotation, refractive index, including conditions and a comparison to the literature for known compounds, should be provided. For crystalline compounds, the method used for recrystallisation should also be documented (that is, solvent etc.).

Mass spectra and a complete numerical listing of 1H,13C NMR peaks in support of the assigned structure, including relevant 2D NMR and related experiments (that is, NOE, etc.) are required. As noted in Analytical above, authors are requested to provide copies of these spectra. Infrared spectra that support functional group modifications, including other diagnostic assignments, should be included. High-resolution mass spectra are acceptable as proof of the molecular weight providing the purity of the sample has been accurately determined as outlined above.

Polymers and macromolecules

For all soluble polymers, an estimation of molecular weight should be provided by size exclusion chromatography, including details of columns, eluents and calibration standards, intrinsic viscosity, MALDI TOF, etc. In addition, full NMR characterisation (1H,13C) as for organic compound characterisation above.

For Gel Permeation Chromatography, molecular weight (Mw), molecular number (Mn) polydispersity index (PDI), and internal standards used should be specified, and associated images/spectra should be made available on submission. We suggest authors deposit their data in an appropriate repository. Where this isn’t possible, we ask authors to include the data as part of the article Supplementary Information (SI).

Synthetic procedures

These should be described in enough detail so that a skilled researcher is able to repeat them. They should include the specific reagents, products and solvents with all of their amounts (g, mmol, for products: %), as well as clearly stating how the percentage yields are calculated.

  • Reaction times, temperature and solvent quantities should be reported
  • Reactions requiring heating - provide the heat source
  • Reactions conducted using microwave heating - information on the type of vessel used and how the temperature was monitored should be given as well as the temperature reached or maintained
  • Light-promoted reactions - report the light source and specific conditions
  • Describe purification methods in detail
  • GC or HPLC traces should be supported with retention times and separation conditions (support, solvent and flow rate)
  • Centrifugation - includes rotation speed, centrifugation/dialysis time, solution for resuspension, resuspension time and procedure for each centrifugation step

Synthetic procedures should also include all the characterisation data for the prepared compound or material. For a series of related compounds at least one representative procedure that outlines a specific example that is described in the text or in a table and that is representative of the other cases should be provided. For a multistep synthesis, spectra of key compounds and the final product should be included.

System models

Systems Biology Markup Language (SBML) is a computer-readable format for representing models of biochemical reaction networks. SBML is applicable to metabolic networks, cell-signalling pathways, regulatory networks, and many others.

We encourage authors to prepare models of biochemical reaction networks using SBML and to deposit the model in an open database such as the BioModels database or MetabolicAtlas.

Include some physical or experimental validation. Studies that screen a molecule against a set of receptors with no link to physical or experimental data are not suitable for publication.

X-Ray crystallography

These guidelines provide details for the presentation of single crystal and powder diffraction data; they apply to submissions to any of our journals.

Authors should present their crystal data in a CIF (Crystallographic Information File) format and deposit this with the (CCDC) before submission. Data will be held in the CCDC's confidential archive until publication of the article, but it will be made accessible to reviewers and the publisher assigned to review the data.

At the point of publication, any deposited data will be made publicly available through the CCDC Access Structures service. In addition, organic and metal-organic structures will be curated into the Cambridge Structural Database, and inorganic structures will be curated into the Inorganic Crystal Structures Database (FIZ Karlsruhe).

Upon deposition, each data set is assigned a Digital Object Identifier (DOI), so that the crystal structure is unambiguously identified and registered.

Include CCDC or ICSD numbers in the manuscript prior to submission as part of a Data Availability Statement. During submission authors will be asked to cite CCDC or ICSD reference numbers; CIFs should not be submitted with the manuscript. Any revised CIFs should be deposited directly with the CCDC before the revised manuscript is submitted to us.

In addition, authors are required to provide a checkCIF report for their reported crystal data. The checkCIF report can be obtained via the International Union of Crystallography's (IUCr) , or as part of the CCDC deposition process. Any ‘level A' alerts in the report should be explained in the submission details for the article or an explanation provided within the submitted CIF. Authors should submit the checkCIF reports to the ÀË»¨Ö±²¥ along with the manuscript files.

If the editor deems it necessary during the peer-review process, the crystallography associated with the manuscript may undergo specialist crystallographic assessment, in which case a report will be provided along with the other reports from reviewers. Any points raised in this assessment should be attended to and all revised CIFs should be deposited with the CCDC prior to uploading the revised manuscript.

For recommended information to include in your CIF, please see the CCDC CIF . If SQUEEZE or MASK procedures are used, this should be noted in the CIF file.

We encourage authors to include hkl data in the deposited CIF file. Alternatively authors can submit hkl data and the structure files (.fcf) separately during deposition with the CCDC. Raw data accompanying a structure should be made available by the authors for the review process, on request.

Details of the data collection and CCDC numbers should be given in the Data Availability Statement.

For relevant structures that are published as CSD communications, and that have not appeared in the manuscript or a previous journal publication, details should be included in the Data Availability Statement and the appropriate DOI should be cited as a reference in the manuscript.

Where there is significant discussion about the crystallography, the description may be given in textual or tabular form, although the latter is more appropriate if several structure determinations are being reported in one paper. A table of selected bond lengths and angles, with estimated standard deviations, should be restricted to significant dimensions only. Average values may be given with a range of E.S.D.s for chemically equivalent groups or for similar bonds.

Procedures for data collection and structure analysis can be provided as part of the Supplementary Information. The following data are recommended:

  • Chemical formula and formula weight (M)
  • Crystal system
  • Unit cell dimensions (Ã… or pm, degrees) and volume, with estimated standard deviations, temperature
  • Space group symbol (if non-standard setting give related standard setting)
  • Number of formula units in unit cell (Z)
  • Number of reflections measured and/or number of independent reflections, Rint
  • Final R values (and whether quoted for all or observed data)
  • Flack or Rogers parameter (if appropriate)

For example:

Single crystals of [Pd{C(CO2Me)[C(CO2Me)C(CO2Me) = C(CO2Me)C(CO2Me) = C(CO2Me)]C6H3[CH(Me)NH2]-2-NO2-5}Br] 4 were recrystallised from dichloromethane, mounted in inert oil and transferred to the cold gas stream of the diffractometer.

Crystal structure determination of complex 4:

Crystal data. C28H31BrCl4N2O14Pd, M = 947.66, orthorhombic, a = 11.096(1), b = 17.197(2), c = 19.604(3) Ã…, U = 3741.0(9) Ã…3, T = 173 K, space group P212121 (no.19), Z = 4, 6013 reflections measured, 5665 unique (Rint= 0.031), which were used in all calculations. The final wR(F2) was 0.099 (all data).

There may be cases where authors do not wish to include details or extensive discussion of a crystal structure determination. Examples include where only the connectivity has been established, data is marked as low quality at the CCDC, the structure is not integral to the conclusions of the article, or the structure has been discussed in a previous publication. Authors should be mindful of unnecessary fragmentation and the editor’s decision on this will be final.

Authors are encouraged to submit powder diffraction crystallographic data as a CIF (Crystallographic Information File) file to an appropriate repository,such as the ICDD or CCDC, please see the Data Sharing policy for further details. For powder diffraction data, please do not include CCDC numbers as part of the manuscript submission process. The reference numbers and DOIs should be cited in a data availability statement. For information on how to cite crystallographic data in your manuscript, please see the section on Data Citation.  

Authors should combine multiple data sets for a given manuscript into a single file. The individual structures in the combined file should be separated from each other by the sequence #===END at the beginning of a line.

Authors should identify the manuscript with which the electronic file is associated when they submit the file by entering the name of the manuscript at the top of the electronic file.

The information required for deposition includes the following:

  • A table of final fractional atomic coordinates
  • Any calculated coordinates (for example, hydrogen)
  • A full list of bond lengths and angles with estimated standard deviations
  • A full list of displacement parameters in the form Bij or Uij (in Ã…2 or pm2)
  • Full details of the refinement
  • Profile difference plots for all analyses. Where a range of similar analyses are presented a minimum number of representative plots may be given

Unrefined powder diffraction data should normally be reported only if the data form part of the discussion presented in the paper, and should be restricted to new materials. In such cases, the following experimental details should be provided in either textual or tabular format:

  • Diffractometer name and model
  • Radiation wavelength (Ã…)
  • Temperature of data collection
  • Unit cell dimensions (Ã… or pm, degrees), if determined

Tables of 2θ data, or diagrams showing diffraction patterns of reaction products, should not normally be published in print unless they have some distinct feature of relevance that requires such detail to be present. In most cases, such data may be provided as Supplementary Information (SI).

For cases where the materials are new, but have similar powder data to other well-characterised materials, such data should not usually be included in the paper but can be deposited in an appropriate repository, with the relevant reference number included in a Data Availability Statement, and cited.

For refined powder diffraction data (where atomic coordinates have been determined), if the procedures for data collection and structure analysis were routine, their description may be concise. When the analysis has not been of a routine nature, the authors should briefly detail the procedures used. In most cases, a table of atomic coordinates may be provided, which should give details of occupancies that are less than unity.

Anisotropic thermal parameters may be included if they form an important aspect of the study. Selected bond lengths and angles, with estimated standard deviations, should be given.

For Rietveld refinements, an observed + calculated + difference profile plot should normally be given for each structure determination, except where a significant number of similar refinements have been carried out. In such cases, only the minimum number of representative plots should be included in the article, with additional plots being deposited in an appropriate repository and cited, or included in the SI.

The following information should be provided:

  • Diffractometer name and model
  • Radiation wavelength (Ã…)
  • Temperature of data collection
  • Step size
  • Chemical formula and formula weight (M)
  • Unit cell dimensions (Ã… or pm, degrees)
  • Space group
  • Number of formula units in unit cell (Z) 
  • Number of reflections
  • Final R values (Rwp, Rexp and Rl) and method of background treatment


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