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Mass spectra: Br and Cl isotope patterns template
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EI mass spectrum sketches of 1-bromopropane (M⁺• 122/124, 1:1) and 2-chloropropane (M⁺• 78/80, 3:1; M − CH₃ 63/65), both with C₃H₇⁺ m/z 43, plus the Cl, Br, Cl₂, Br₂ and ClBr isotope clusters.
What the template shows
- M and M + 2 peaks: about 1 : 1 for one bromine (⁷⁹Br/⁸¹Br), about 3 : 1 for one chlorine (³⁵Cl/³⁷Cl)
- EI mass spectra (sketches) and isotope clusters
- rel. abundance / %
- Molecular-ion clusters (M, M + 2, M + 4), from natural abundances
- Natural abundance: ⁷⁹Br 50.7 %, ⁸¹Br 49.3 % → M : M + 2 ≈ 1 : 1. ³⁵Cl 75.8 %, ³⁷Cl 24.2 % → M : M + 2 ≈ 3 : 1.
- Any fragment that keeps the halogen shows the same pair (63/65 in 2-chloropropane); fragments that lost it (m/z 43) do not.
- Two halogens: Cl₂ 9 : 6 : 1, Br₂ 1 : 2 : 1, ClBr 3 : 4 : 1 (M, M + 2, M + 4).
- Loss of the halogen atom gives C₃H₇⁺ (m/z 43): the base peak in both spectra.
- Peak heights other than the isotope ratios are illustrative; check measured spectra in the NIST WebBook or the free MolDraw mass-spec viewer.
- Typical literature values; compare real spectra in SDBS · every part of this figure is editable
Drawn with 8 atoms, 65 shapes – every one editable in MolDraw.
Sources
How to use this template
- Press Edit in MolDraw. The template opens on the canvas of the free MolDraw editor.
- Change anything: move structures, edit atoms and labels, recolour highlights or delete what you do not need.
- Add your own structures, arrows and text next to it, or combine several templates on one page.
- Export the drawing as PNG, SVG or PDF for slides, worksheets, theses and papers.
Frequently asked questions
Is the Mass spectra: Br and Cl isotope patterns template free?
You can preview the Mass spectra: Br and Cl isotope patterns template here and open and edit it in MolDraw for free. Downloading or exporting it is part of MolDraw Pro, together with the other premium templates.
Can I edit the Mass spectra: Br and Cl isotope patterns template?
Yes. It opens as an ordinary MolDraw drawing, so every structure, arrow, label and colour can be changed, and you can add your own content around it.
Is the chemistry checked?
Every structure is checked with RDKit and every curly arrow passes MolDraw’s electron-flow audit. The sources used are listed on this page.
Are the spectra real data?
The spectra are schematic, drawn to the standard chemical shifts, splitting patterns and absorptions given in textbooks, so they are clear for teaching and exam practice.