Chemistry Manuscript Conventions: ACS Style & SI

Chemistry manuscripts follow a formatting and nomenclature tradition that differs in specific, consistent ways from the generic IMRaD (Introduction, Methods, Results, and Discussion) template used across much of the biomedical and social sciences. The dominant reference point for that tradition in the United States and in most ACS-published journals is the ACS Style Guide, and the single most distinctive structural element chemistry authors have to manage — one that has no real equivalent in most other disciplines — is the Supporting Information (SI) file. This guide covers ACS nomenclature and style conventions, what belongs in Supporting Information and how it is structured, the Table of Contents (TOC) graphic requirement, and where journal-specific formatting rules diverge from the general style guide.

Why chemistry manuscripts follow a distinct convention set

Chemistry papers report on specific chemical entities — compounds, reactions, materials — that must be identified unambiguously enough for another lab to reproduce and verify them. That reproducibility requirement drives most of what makes chemistry manuscript conventions distinctive: standardized nomenclature so a compound name maps to exactly one structure, a dedicated Experimental Section that reads more like a structured protocol than narrative prose, and an entire secondary document (the SI) built specifically to hold the characterization data — NMR spectra, mass spectrometry, X-ray crystallographic data, HPLC traces — that would make a main-text Methods section unreadable if included in full. None of this replaces IMRaD wholesale; a typical chemistry Article still moves through an introduction, results, and discussion. It layers additional, chemistry-specific structural requirements on top.

The ACS Style Guide: the field’s reference standard

The ACS Style Guide: Effective Communication of Scientific Information, published by the American Chemical Society (now in its third edition, 2006, edited by Anne M. Coghill and Lorrin R. Garson), is the reference manual most ACS journals point authors to for nomenclature, units, abbreviations, and general scientific-writing conventions. It sits alongside, not in place of, each individual journal’s own author guidelines — where a specific ACS journal’s guidelines and the general style guide disagree, the journal-specific guidance published on ACS Researcher Resources governs. In practice, most working chemists encounter the style guide’s conventions secondhand, through journal templates and by following how similar papers in their subfield are written, rather than by reading the manual directly — but its rules are what those templates and house styles are built on.

Chemical nomenclature: IUPAC, CAS, and avoiding trivial names

The ACS Style Guide directs authors to give a systematic name — from either IUPAC nomenclature rules or Chemical Abstracts Service (CAS) index nomenclature — for each title or key compound, typically in the Experimental Section where the compound is first prepared or characterized. A few conventions follow from that baseline:

Trivial (common) names are discouraged as the primary identifier for a compound, precisely because they don’t map one-to-one onto a structure the way a systematic name does. A well-known trivial name may still appear in running prose for readability, but the systematic name is expected at first use and in the Experimental Section.
CAS Registry Numbers are recommended for less-familiar compounds, giving readers and databases an unambiguous identifier independent of whatever name is used in the text.
Trade names, when used, should be defined at first use and capitalized, since they are proprietary identifiers rather than chemical descriptors.
Specialized or field-specific nomenclature (common in polymer chemistry, organometallic chemistry, and materials science) is generally expected to come with a short nomenclature note defining any non-standard terms or abbreviations used, rather than assuming the reader already knows a subfield’s shorthand.
Journal abbreviations in the reference list follow the Chemical Abstracts Service Source Index (CASSI), the standard chemistry-journal abbreviation list, rather than an author’s own shorthand.

This nomenclature discipline is also why chemistry manuscripts lean more heavily on structure-drawing software (ChemDraw and equivalents) for both in-text schemes and SI content than most other disciplines — a drawn structure is often a faster, less ambiguous identifier than any name, systematic or otherwise.

The Experimental Section (or Materials and Methods)

Where a biomedical IMRaD paper has a narrative Methods section, a chemistry manuscript’s Experimental Section (sometimes still titled Materials and Methods, depending on the journal) is written closer to a reproducible protocol: reagent sources and purity/grade, instrument models and operating parameters, step-by-step synthetic procedures, and full characterization data for every new compound reported — typically melting point, optical rotation where relevant, and references to the corresponding NMR/MS/IR/elemental-analysis data, with the bulk of that raw characterization data itself deposited in the Supporting Information rather than printed in full in the main text. The expectation across ACS and most other chemistry journals is that a competent chemist in the subfield could reproduce the reported synthesis from this section without needing to contact the authors.

Supporting Information (SI): what it is and how it’s structured

Supporting Information is the single largest structural difference between a chemistry manuscript and papers in most other fields — see CASRAI’s general guide to supplementary materials for how the equivalent category works outside chemistry. It is submitted as a separate file (or files) alongside the main manuscript, is peer-reviewed alongside it, and is published as a permanent, citable part of the record — but it is not typeset into the main article the same way the Experimental Section is.

Per ACS’s published submission guidance, Supporting Information conventionally includes:

Full characterization data for new compounds — NMR spectra images (¹H, ¹³C, and any other relevant nucleus), high-resolution mass spectrometry (HRMS) data, IR spectra, and, where applicable, HPLC traces establishing purity.
X-ray crystallographic data (typically as a CIF file) for any reported crystal structures, often alongside a separate deposition with the Cambridge Crystallographic Data Centre (CCDC).
Extended experimental detail, additional figures, tables, or computational output that supports but isn’t essential to the main narrative.
Photographs of experimental setups, additional control experiments, or other material a journal or reviewer may reasonably want to check without it cluttering the main text.

Formatting-wise, ACS’s author guidance is specific: each SI file needs a brief, non-sentence description of its actual contents, including the file type extension, placed at the end of the manuscript before the reference list — for example, “¹H NMR spectra for all compounds (PDF)” or “Additional experimental details, materials, and methods, including photographs of experimental setup (DOC).” Many ACS journals also expect the SI document itself to open with a cover sheet listing the authors and manuscript title and, where the SI is long, a table of contents, with pages numbered consecutively starting at S1. PDF is the most broadly accepted SI format; authors are directed to check the specific journal’s list of acceptable file types before submission, since accepted formats and size limits vary by journal.

This is not an ACS-only convention — most chemistry publishers, including the Royal Society of Chemistry and Wiley’s chemistry titles, use functionally similar SI structures, though naming, cover-sheet requirements, and file-size limits differ by publisher and by journal.

The Table of Contents (TOC) graphic

Most ACS journals require a Table of Contents graphic (also called a TOC graphic or, informally, a graphical abstract) submitted at the same stage as the manuscript itself: original, unpublished artwork — not simply reused from an in-text figure — showing no photographs of people, and labeled for TOC use only rather than embedded as a numbered figure. The Royal Society of Chemistry uses a closely related concept it calls a “table of contents entry”: an eye-catching graphic paired with a short (roughly one- to two-sentence) summary submitted as separate text rather than embedded in the image itself. Exact dimensions, DPI, and file-format requirements are journal-specific and change periodically, so authors should confirm the current specification on the individual journal’s author-guidelines page rather than assume one figure size works across the whole publisher’s journal list. For a broader treatment of this requirement across publishers beyond chemistry, see CASRAI’s graphical abstract guide.

Journal-specific formatting: why “ACS style” isn’t one style

“ACS style” is often used as shorthand, but ACS itself publishes dozens of journals — Journal of the American Chemical Society (JACS), Organic Letters, ACS Nano, Chemical Reviews, ACS Sustainable Chemistry & Engineering, and many others — each with its own author-guidelines page (indexed by CODEN on ACS Researcher Resources) covering that journal’s specific manuscript types, scope, and formatting expectations. In practice this means:

Manuscript types differ by journal. A journal may define distinct categories — Communications/Letters (short, priority-focused reports), full Articles, Perspectives, and Reviews — each with its own length expectations and structural requirements, and those categories and their definitions are not identical across ACS journals.
SI conventions and accepted file formats vary by journal, even though the general SI concept is shared across the ACS portfolio.
Reference and citation formatting can vary between a numbered-reference style and an author-date style depending on the specific journal, even though most ACS journals default to sequential numbering.
Non-ACS chemistry publishers use a related but distinct convention set. Royal Society of Chemistry journals, Wiley’s Angewandte Chemie family, and Elsevier’s chemistry titles all expect broadly similar nomenclature discipline and SI-style supplementary data, but each maintains its own house style, TOC/graphical-abstract specification, and reference format, so a manuscript prepared strictly to one publisher’s template will typically need reformatting before submission elsewhere.

The practical takeaway for authors and the research-administration staff supporting them: treat the ACS Style Guide as the baseline convention set for chemistry writing, but always verify the target journal’s own current author-guidelines page before final formatting — general style-guide conventions and journal-specific submission requirements are not interchangeable, and the journal-specific page is what reviewers and editorial staff will actually check the manuscript against.

Reference and citation conventions

Most ACS journals use a numbered citation style — references cited sequentially by superscript or bracketed number as they first appear in the text, with a correspondingly numbered reference list (rather than an alphabetical author-date list) — though some ACS journals support an author-date option, and authors should confirm which their target journal expects. Journal names in the reference list are abbreviated per CASSI rather than spelled out or abbreviated informally. Reference-management software (EndNote, Zotero, and others) generally ships with an “ACS” citation style preset that follows these conventions, though it is still worth spot-checking a generated reference list against the target journal’s own examples, since style-preset accuracy varies.

Common pitfalls

Using a trivial name as the sole identifier for a title compound instead of leading with the systematic (IUPAC or CAS) name at first use.
Treating the SI as an appendix for anything that didn’t fit rather than a defined set of characterization data with its own file-description and formatting conventions — an under-described or unlabeled SI file is a common source of revision requests.
Assuming one ACS journal’s SI, TOC-graphic, or reference-style rules apply to another ACS journal, or to a non-ACS chemistry publisher, without checking the specific target journal’s current author guidelines.
Reusing an in-text figure as the TOC graphic where the journal requires original artwork created specifically for that purpose.
Omitting CAS Registry Numbers or full characterization data for new or less-common compounds, which is one of the more common reasons a chemistry manuscript is returned for revision before it ever reaches peer review.

Frequently asked questions

Is the ACS Style Guide required reading for submitting to a non-ACS chemistry journal?

No. It’s the dominant style reference for ACS-published journals specifically, but Royal Society of Chemistry, Wiley, and Elsevier chemistry titles each maintain their own house style. The underlying conventions — systematic nomenclature, a detailed Experimental Section, SI for characterization data — are broadly shared across chemistry publishing, but the specific formatting rules are not identical.

Does Supporting Information get peer-reviewed?

Yes. SI is submitted alongside the manuscript and reviewed as part of the same submission, and it becomes a permanent, citable part of the published record — it is not a lightly-checked appendix, even though it isn’t typeset into the main article body.

What file format should Supporting Information be submitted in?

PDF is the most broadly accepted format across ACS journals, but authors should check the specific target journal’s list of acceptable file types and size limits before submission, since these vary by journal.

Is the TOC graphic the same thing as a graphical abstract?

They serve the same basic purpose and are often used interchangeably in conversation, but the exact term, required elements, and specification differ by publisher — ACS calls it a “Table of Contents graphic,” the Royal Society of Chemistry a “table of contents entry.” See CASRAI’s graphical abstract guide for the broader cross-publisher picture.

Do all chemistry subfields follow the same nomenclature conventions?

The core principle — use a systematic, unambiguous name for reported compounds — holds across subfields, but the applicable naming system differs: organic and inorganic chemistry lean on IUPAC/CAS nomenclature, while polymer chemistry, biochemistry, and materials science often layer field-specific naming and abbreviation conventions on top, which is why the style guide recommends a nomenclature note for specialized terms.

Related discipline-specific manuscript conventions

Chemistry is one of several fields where CASRAI documents discipline-specific manuscript conventions in depth: see the mathematics paper writing conventions guide for the theorem-proof structure mathematics uses in place of chemistry’s Experimental Section and SI model, or the economics job market paper guide for a social-science field with its own distinct structural norms. For chemistry authors specifically, CASRAI also covers ChemRxiv vs. bioRxiv as preprint options, PubChem as a compound/bioassay data repository relevant to reporting chemical data, and LaTeX and Overleaf for collaborative writing, widely used for chemistry manuscripts prepared with ACS LaTeX templates.