Environmental sciences, including environmental chemistry and toxicology, are highly interdisciplinary fields that integrate researchers with various backgrounds and expertise. This interdisciplinary aspect is critical to addressing issues of chemical pollution, environmental sustainability, and health. However, a standardized method for reporting chemical data is needed to address these issues effectively. This becomes increasingly important as both the number of chemical structures and our reliance on and use of computational analysis and cheminformatics tools grow. This paper provides background, examples, and recommendations on how to report chemical data in a findable, accessible, interoperable, and reproducible (FAIR) manner within environmental science disciplines. Ultimately, the goal is to broaden the scope and applicability of environmental research to help the entire community tackle the issues of chemical pollution and sustainability in a comprehensive manner.

Many compounds have two or more names correctly formed in accordance with more than one of the methods documented in this book for the same structure. In such cases, this chapter selects the one name that is to be the IUPAC preferred name (PIN). Topics discussed include: (1) selecting the preferred type of IUPAC nomenclature; (2) selecting preferred retained names, preferred systematic names, and preselected names for parent hydrides; (3) selecting the preferred method for modifying the degree of hydrogenation of parent hydrides; (4) selecting the preferred retained name for functional parent compounds; (5) selecting the preferred suffix for the principal characteristic groups; (6) selecting preferred and preselected prefixes for substituent groups. Construction of different types of names is illustrated.

Science, including mathematics, physics, and, of course, chemistry, has its own language and symbols and names we learn in school. However, to teach it, communicate it, and use it, we use our own native languages. Most of the scientific literature, including this article, is in English, as are the texts published by the various scientific unions, including the International Union of Pure and Applied Chemistry (IUPAC), to define scientific nomenclature, terminology, and presentation. However, it is essential that these fundamental texts are available in as many languages as possible to facilitate their teaching, learning, and use throughout the world. It should be noted, however, that the translation of these texts into different languages is a complex task that requires some choices due to the lack of obvious alternatives or the cacophony of some terms. In this paper, we provide some details on the challenges, compromises, and difficult decisions involved in translating the IUPAC Nomenclature Brief Guides into Spanish.

Primary publications of congener numbering shorthand systems for PCB congener identification were reviewed, including the original Ballschmiter-Zell (BZ) system; recommended changes by Schulte and Malisch, and Guitart et al.; and listings by the Chemical Abstracts Service. Comparisons of the various congener numbering shorthands and chlorine substitution numberings in the structural name listings are presented. Several changes, to adhere more closely to IUPAC rules, have been incorporated into the BZ structural nomenclature, and these resulted in renumbering congeners. These corrected listings have been erroneously identified as "IUPAC" numbers, a misnomer, because IUPAC has not published a shorthand system. Guitart pointed out additional inconsistencies with IUPAC rules for nine congeners which would result in further order changes, but did not recommend renumbering, to avoid further confusion. We noted an additional error in the structural name for congener 97, named 2,2',3',4,5 using Ballschmiter and Zell nomenclature and 2,2',3,4',5' using strict IUPAC nomenclature. This renaming would cause the renumbering of the IUPAC number system reported by Guitart for isomers 91 through 98. No further changes are recommended, however. Tables summarizing each publication, and the discrepancies between them are provided in hopes of clarifying the current state of the nomenclature.

Steroid compounds are important messengers in the human body that can be described using multiple nomenclature systems, each reflecting a different perspective on structure or function. Chemical nomenclature, based on IUPAC conventions, classifies steroids according to their ring structure and functional groups, whereas functional nomenclature reflects a compound's source, biological action, regulatory pathways, metabolism, or clinical application. These parallel systems are often applied inconsistently across disciplines, leading to ambiguity in interpretation and communication. This review outlines the foundations of chemical and functional naming, highlights circumstances in which nomenclature becomes inconsistent, and illustrates how physiology, molecular biology, receptor diversification, genetics, oncology, and the microbiome complicate terminology. Because clinicians, biochemists, pharmacologists, and researchers often apply different naming logics, coherent definitions and consistent usage are necessary for clear scientific discourse. This review proposes considerations to support more precise application of steroid nomenclature in academic publications.

transition metal. The IUPAC lists the 15 elements La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, under the collective name lanthanoid (/ˈlænθənɔɪd/) A lanthanide () is any of the 15 metallic chemical elements with atomic numbers 57–71, from lanthanum through lutetium. In the periodic table, the first fourteen (up to ytterbium) fill the 4f orbitals. Lutetium (element 71) is also often considered a lanthanide, despite being a d-block element and a transition metal. The IUPAC lists the 15 elements La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, T A lanthanide () is any of the 15 metallic chemical elements with atomic numbers 57–71, from lanthanum through lutetium. In the periodic table, the first fourteen (up to ytterbium) fill the 4f orbitals. Lutetium (element 71) is also often considered a lanthanide, despite being a d-block element and a transition metal. The IUPAC lists the 15 elements La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, under the collective name lanthanoid (), which it recommends as chemically more correct for this series. The informal chemical symbol Ln is used in general discussions of lanthanide chemistry to refer to any lanthanide. All but one of the lanthanides are f-block elements, corresponding to the filling of the 4f electron shell. Lutetium is a d-block element (thus also a transition metal), and on this basis its inclusion has been questioned; however, like its congeners scandium and yttrium in group 3, it behaves similarly to the other 14. The term rare-earth element or rare-earth metal is often used to include the stable group 3 elements Sc, Y, and Lu in addition to the 4f elements. All lanthanide elements form trivalent cations, Ln3+, whose chemistry is largely determined by the ionic radius, which decreases steadily from lanthanum (La) to lutetium (Lu). Several lanthanides can also form +2 and even +4 oxidation states. In presentations of the periodic table, the f-block elements are customarily shown as two additional rows below the main body of the table. This convention is entirely a matter of aesthetics and formatting practicality; a rarely used wide-formatted periodic table inserts the 4f and 5f series in their proper places, as parts of the table's sixth and seventh rows (periods), respectively. * Not including initial [Xe] core f → f transitions are symmetry forbidden (or Laporte-forbidden), which is also true of transition metals. However, transition metals are able to use vibronic coupling to break this rule. The valence orbitals in lanthanides are almost entirely non-bonding and as such little effective vibronic coupling takes, hence the spectra from f → f transitions are much weaker and narrower than those from d → d transitions. In general this… Cr…

Significant ambiguity exists in the scientific community with regard to the nomenclature of 26-hydroxylated oxysterols. Oxysterols constitute an important class of compounds that have biological roles in the regulation of cholesterol synthesis and as endogenous selective estrogen receptor modulators (SERMs). The ambiguity is attributable to deviations from clearly stated IUPAC rules and is likely to increase as more biologically active oxysterols are identified. This review provides a uniform approach to the naming of 26-hydroxylated sterols for those of current interest and for those on the horizon such as oxysterols of lanosterol that retain the unsaturation at C-24 and C-25 such as (E)-26-hydroxylanosterol. Using this molecule as a starting point, this review hopes to establish a common language to keep all investigators on the same page.