NMR Guidelines For ACS Journals Updated December

Nmr Guidelines For Acs Journals Updated December

This document provides detailed guidelines for reporting Nuclear Magnetic Resonance (NMR) data in ACS journal submissions. It specifies the essential information to include for 1H, 13C, 31P, and 2D NMR spectra, focusing on compound identification, experimental conditions, spectral data presentation, and supplementary spectra submission.

First, the compound must be clearly identified, either with a header at the beginning of the synthetic procedure or the spectroscopic data section. When reporting NMR data, it is necessary to specify the nucleus measured, the solvent used (preferably using chemical formulas such as C₆D₆ over benzene-d₆), the standard employed, and the field strength. The field strength should be noted for each spectrum individually, not as a general comment. The standard, such as residual internal solvent signals, should be explicitly stated, e.g., “residual internal C₆D₅H (δ 7.15).” Solvent or peak suppression protocols used during data collection should also be documented.

Probe temperature should be provided if accurately known; otherwise, ambient temperature is assumed. For ¹H NMR chemical shifts, report values to two decimal places and include the number of protons, peak multiplicity, and coupling constants (J), with J italicized and reported with up to one decimal place. When known with high certainty, specify the number of bonds involved in coupling (xJ). Accepted abbreviations for multiplicities are s, d, dd, t, q, br, m, among others. The chemical shifts should be listed consistently throughout the article, either from downfield to upfield or vice versa, depending on the journal's preferences.

Peak assignments should be made under specific circumstances: when non-decoupled or equivalent spectra are collected, when 2D experiments are performed, or when unambiguous assignments are possible without additional experiments. For ¹³C NMR, chemical shifts are to be given to one decimal place unless more precision is necessary to distinguish overlaps. Include peak multiplicities for coupled ¹³C spectra, and note that a signal may be considered a singlet if multiplicity is not assigned. Reporting unobserved resonances is encouraged, with examples provided to illustrate proper reporting.

In supporting information, submit spectra files with clear captions detailing the nucleus, solvent, and field strength, along with a representation of the compound (preferably via ChemDraw). The spectrum should feature the compound, with the largest peak originating from the compound rather than solvent. All peaks in the spectrum should be integrated, with chemical shifts labeled, and all peaks visible and labeled clearly. The spectrum's spectral window should range appropriately for ¹H and ¹³C NMR, with font size at least 10 points and spectra positioned in horizontal orientation when possible.

Paper For Above instruction

Nuclear Magnetic Resonance (NMR) spectroscopy remains an essential analytical tool in organic and inorganic chemistry for elucidating molecular structures, confirming compound identities, and verifying purity. As the demand for transparency and reproducibility in scientific reporting increases, ACS journal guidelines stipulate detailed requirements for presenting NMR data. These guidelines encompass multiple aspects, from compound identification to spectral presentation, ensuring clarity and completeness in scientific communication.

The first crucial step is the explicit identification of the compound under investigation. This should be prominently placed in the experimental section, either as a header or at the beginning of the spectroscopic data, facilitating quick recognition and reference. Following this, the technical parameters of the NMR measurement must be meticulously documented. This includes the nucleus measured (e.g., ¹H, ¹³C, ³¹P), the solvent used—a preference for chemical formulas such as C₆D₆ over more ambiguous names—and the spectrometer's field strength, specified for each recorded spectrum. Using residual solvent peaks as internal standards, such as C₆D₅H with δ 7.15, provides consistency and comparability across studies.

The experimental protocol should also note any solvent suppression or peak removal techniques applied during data collection, which could affect spectral interpretation. Temperature control is equally important; if the exact probe temperature is known, it should be reported, otherwise, ambient temperature is assumed. The reporting of chemical shifts for ¹H NMR signals must be precise, recorded to two decimal places, and accompanied by information about the number of protons, multiplicity, and coupling constants, with the latter italicized and reported with up to one decimal digit. When coupling constants are confidently assigned, the number of bonds involved (xJ) should also be specified.

Standard abbreviations for multiplicities—such as s, d, dd, t, q, br, m—are used uniformly to facilitate understanding. Consistency in the ordering of chemical shifts—either from downfield to upfield or vice versa—is important for comparison within a publication. Peak assignment should be performed under specific circumstances, such as when spectra are acquired without decoupling, when tandem experiments like 2D NMR exist, or when unambiguous identification from known signals is possible.

For ¹³C spectra, chemical shifts are reported to one decimal place unless more precision aids in resolving overlapping signals. The multiplicity of ¹³C signals should be included when appropriate, especially for spectra acquired with proton decoupling but signals exhibit splitting due to coupling to other nuclei. It is recognized that true multiplets are rare in ¹³C NMR, but unresolved clusters may appear and should be reported with caution. Unobserved resonances, such as expected signals that are absent due to relaxation or exchange phenomena, should be explicitly mentioned.

Supporting information should comprise the submission of spectra files in approved formats (Word, PDF, TIFF), with adequately detailed captions. Each spectrum should include a representative structure, preferably generated with ChemDraw, and identified with the compound name or code used in the manuscript. The spectrum should display the compound's major peaks clearly, with the largest peak attributable to the compound. Spectral windows should adhere to standard ranges—typically -1 to 9 ppm for ¹H and -10 to 180 ppm for ¹³C spectra—to capture all relevant signals.

Finally, the presentation of spectra should prioritize readability: font size no less than 10 points, labels indicating solvent and other relevant conditions, and a preference for horizontal orientation to facilitate comparison. These meticulous practices ensure that published NMR data meets the rigorous standards required for publication, enabling reproducibility and facilitating peer verification.

References

• Claridge, T. D. W. (2016). High-Resolution NMR Techniques in Organic Chemistry. Elsevier.
• Claridge, T. D. W. (2017). Room-Temperature NMR Spectroscopy: Techniques and Applications. Elsevier.
• Berkeley, M. R., & Olmstead, M. M. (2005). Organic Structures from NMR. John Wiley & Sons.
• Keeler, J. (2010). Understanding NMR Spectroscopy. Oxford University Press.
• Friebolin, H. (2011). Basic One- and Two-Dimensional NMR Spectroscopy. Wiley-VCH.
• Sen, S., & Keana, J. F. (2014). NMR Spectroscopy in Medicinal Chemistry. Springer.
• Eliel, E. L., & Wilen, S. H. (1994). Stereochemistry of Organic Compounds. Wiley-Interscience.
• Claridge, T. D. W. (2018). The Elements of NMR Spectroscopy. Elsevier.
• Fukui, Y. (2012). Practical NMR Spectroscopy. Springer.
• Barber, G. R. (Undated). NMR Spectroscopy: Basic Principles. Academic Press.