We are pleased to introduce version 11.3 of our ChemDoodle 2D software. This update is free for all ChemDoodle subscriptions, Lifetime and Site licenses. Licenses are as little as $18, and we have a free trial available at: https://www.chemdoodle.com/


Various free radicals named by ChemDoodle 2D. ChemDoodle 2D has many options for naming, some of the relevant radical options are shown.

Executive Summary

ChemDoodle 2D v11.3 is a feature update. The main new feature is expert IUPAC naming support for free radicals. Other major features include new image output sizing options with previews, and stoichiometry table options.


  1. Free radicals are now expertly handled by our IUPAC naming algorithms. These are by traditional rules. Monovalent and multivalent radical centers, as well as multiple radical centers within the same structure are supported. Both trivial and systematic naming is supported. Options are provided, including Section A vs Section D naming rules and carbene naming.
  2. New image output options to manually define image size, instead of the default behavior of automatically sizing the image based on the graphics content measurements. You will be able to choose whether graphics content is scaled to fit custom dimensions. A new preview component is shown in the image settings window to make clear how the final image is laid out. Please see section 15.8.6 of the ChemDoodle 2D User Guide for more information
  3. An option for stoichiometry forms to automatically predefine the measured mass. If you would like undefined experimental reactant measured mass values to be predefined to the defined theoretical reacting mass values, then select this option. This option may help to speed up your use of the stoichiometry form. The predefined measured mass values will be considered as user defined explicit values, which can be further edited. These options are found in the Functions panel of the Preferences window under the Calculations section.
  4. Shadows, gradients and fills can now be applied to bezier curves, pens and polylines, even if they are not closed.


  1. Further CDX and CDXML file support: Fixed the incorrect input of the ElementList data type, better support for styled curves and arrowhead sizing on curves, automatic line feeds from fixed width labels are now properly handled, line type properties on arrowheads are now read in, fixed issue resolving final bezier point in inconsistent files, elliptical arcs can now be written.
  2. Free radicals are now appropriately accounted for in aromaticity detection.
  3. Saving ODG output now correctly displays output options.