Experimental reporting requirements

The Royal Society of Chemistry believes that where possible, all data associated with the research in a manuscript should be as Findable, Accessible, Interoperable and Reusable (FAIR) as possible, enabling other researchers to replicate and build on that research.

For all submissions to Royal Society of Chemistry journals, all data required to understand and verify the research in an article must be made available on submission.

We strongly encourage authors to share and cite machine-readable data files in appropriate repositories. If this is not possible, we encourage authors to include as part of the article supplementary information (ESI).

You can find details on recommended repositories in our Data Sharing Policy.

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.

← View all guidelines for preparing and formatting your article

Experimental reporting requirements for submission

On submission of a manuscript authors should provide all data required to understand and verify the research presented in the article; these should be submitted in the following ways.

• X-Ray crystallographic data and macromolecular structure and sequence data should be deposited in an appropriate repository. Full requirements for these data types are available below.
• All other required data should be submitted as electronic supplementary information. Details of specific data requirements for a journal can be found in the journal specific information.

Experimental data

You should provide descriptions of the experiments in enough detail so that a skilled researcher is able to repeat them. Standard techniques and methods used throughout the work should just be stated at the beginning of the experimental section; descriptions of these are not needed. Any unusual hazards about the chemicals, procedures or equipment should be clearly identified.

Only non-standard apparatus should be described; commercially available instruments are referred to by their stock numbers (for example, Perkin-Elmer 457 or Varian HA-100 spectrometers). The accuracy of primary measurements should be stated. Figures should include error bars where appropriate, and results should be accompanied by analysis of experimental uncertainty.

Please see the sections below for detailed information about how to present specific types of data. For studies that involve the use of live animals or human subjects please refer to our Human & Animal Welfare policy.

Characterisation of new compounds

General guidance

It is the responsibility of authors to provide fully convincing evidence for the homogeneity and identity of all compounds they claim as new, or known compounds made by a new method. Evidence of both purity and identity is required to establish that the properties and constants reported are those of the compound with the new structure claimed.

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.

Reviewers will assess, as a whole, 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 must be accompanied by independent evidence of homogeneity.

Where elemental analytical data cannot be obtained, appropriate evidence which 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. More detailed guidelines for authors submitting to ChemComm, Organic & Biomolecular Chemistry and Organic Chemistry Frontiers can be found in the journal specific information.

Spectroscopic information necessary for the assignment of structure should be given. How complete this information should be must depend upon the circumstances; the structure of a compound obtained from an unusual reaction or isolated from a natural source must be supported by stronger evidence than one that was produced by a standard reaction from a precursor of undisputed structure. Authors are reminded that full spectroscopic assignments may be submitted as electronic supplementary information where their importance does not justify their inclusion in the published paper.

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.

Characterisation within chemical biology

Where biomolecular compounds are synthesised, sufficient evidence for purity and identity must be provided such that the results of the experiment may be trusted.

Authors should provide rigorous evidence for the identity and purity of the biomolecules described. The techniques that may be employed to substantiate identity include the following.

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

The purity must be established by one or more of the following.

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

Sequence verification also needs to be carried out for nucleic acids in molecular biology.

For experiments involving microorganisms sufficient detail should be provided to identify the species being used.

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 ν_max/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; you can find more information about each of these data by clicking on the 'Guide to the presentation of experimental data' button.

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

X-Ray crystallography

These guidelines provide details for the presentation of single crystal and powder diffraction data; they apply to submissions to any Royal Society of Chemistry journal.

A paper in which the result of a crystal structure determination is discussed, but for which the author does not wish to include details or extensive discussion, may be considered appropriate provided that it does not lead to unnecessary fragmentation. The editor will have the final decision. However, the author must provide, as supplementary information, sufficient data to allow a reader to make sure that the point made is correct, and coordinates, etc. will be deposited at the CCDC or FIZ Karlsruhe. The brief description of the determination should be referenced as 'unpublished work'.

When the paper being prepared is a full paper that follows a preliminary Communication in which the author does not wish to discuss the structure again at any length; then he/she may refer back to the original Communication. However, if the structure is discussed in detail in the full paper, the data should be re-presented in full and will be re-published if considered necessary.

Small molecule single crystal data

Authors should present their crystal data in a CIF (Crystallographic Information File) format and deposit any organic or organometallic structural information with the Cambridge Crystallographic Data Centre (CCDC) before they submit their manuscript to us. Data will be held in the CCDC's confidential archive until publication of the article, when data for organic and organometallic compounds will be entered into the Cambridge Structural Database. Authors are encouraged to deposit inorganic crystal structures with the ICSD, hosted by FIZ Karlsruhe.

During submission of a manuscript to the Royal Society of Chemistry using our online submission system, authors will be asked to provide CCDC reference numbers; CIFs should not be submitted with the manuscript (these should have already been deposited with the CCDC/ICSD, see above). Any revised CIFs obtained subsequently should be deposited directly with the CCDC before the revised manuscript is submitted to us. CCDC or ICSD numbers should be included in the manuscript prior to submission. 

CheckCIF

Information for inclusion in the CIF

• 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 B_ij or U_ij (in Ų or pm²)  

Full details of the refinement, which should include the following data.

• Chemical formula and formula weight (M) 
• Crystal system 
• Unit-cell dimensions (Å 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, number of independent reflections, R^_int, θ and index (hkl) range 
• Final R value(s) and whether for all or observed data 
• Method of determination of unit cell dimensions 
• Type of filter or monochromator used 
• Type and wavelength of radiation used 
• Calculated density (D_c) 
• Method of refinement, whether refinement carried out on F or F², treatment of hydrogen atoms 
• Details of weighting scheme used 
• Number of parameters refined and any constraints or restraints applied 
• Definition of R and wR, final value of wR, with a statement of whether unobserved data were included 
• Goodness-of-fit (S) value, maximum/minimum residual electron densities, average and maximum shift/error 
• Programs or packages and computers used (with references) 
• Flack or Rogers parameter (if appropriate)             

The CIF format has data names that correspond to these items.

Authors may make use of Platon SQUEEZE if they wish; however, this is not required. If used, it should be noted in the manuscript and CIF (by appending the created sqf file to the end of the submitted CIF).

Tables of structure factors (F_o, F_c) should not be sent, but copies should be retained by the authors so that they may be made available via the editorial office if requested. Authors may provide hkl files to the editorial office along with their crystal data if they wish, to aid with the crystallographic review process.

Information for inclusion in the manuscript

Communications

Details of the data collection and CCDC numbers should be given in a footnote or in the References/Notes section. 

Full papers

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. 

If the procedures for data collection and structure analysis were routine, their description should be particularly concise. When the analysis was not of a routine nature, the authors should briefly detail the procedures used.

The following data must be presented in the manuscript if there is significant discussion of the crystallography.

• Chemical formula and formula weight (M) 
• Crystal system 
• Unit-cell dimensions (Å 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, R_^int 
• Final R values (and whether quoted for all or observed data) 
• Flack or Rogers parameter (if appropriate)

The following example demonstrates the application of the recommendations in the preceding sections in a full paper. For a communication, the headings should be omitted.

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) Å, U = 3741.0(9) ų, T = 173 K, space group P2^₁2^₁2^₁ (no.19), Z = 4, 6013 reflections measured, 5665 unique (R^_int = 0.031), which were used in all calculations. The final wR(F²) was 0.099 (all data).

Powder diffraction data

If available, authors may submit powder diffraction crystallographic data as a CIF (Crystallographic Information File) file via online submission to the Royal Society of Chemistry. Authors should combine multiple data sets for a given manuscript into a single file. The individual structures in the combined file must be separated from each other by the sequence #===END at the beginning of a line.

Authors must identify with which manuscript 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 B_ij or U_ij (in Ų 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

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
  • R_merge, completeness, multiplicity and I/sigma(I) - both overall and in the outer resolution shell - for data, and
  • R_cryst, R_free 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.

System models

The 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 with the BioModels database. Authors may submit datasets in SBML formats, when they are available, for publication as electronic supplementary information.

Electrophoretic gels and blots

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 provided in the supplementary information on submission. 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 closest molecular mass markers and lanes labelled. All details must 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.

Human & animal welfare

When a study involves the use of live animal subjects, authors should adhere to the ‘Animal Research: Reporting In Vivo Experiments’ (ARRIVE) 2.0 guidelines. When a study involves the use of human subjects, authors should adhere to the general principles set out in the Declaration of Helsinki.

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.