# Free software to draw Newman projections

I need to draw Newman projection of a molecule. Particularly 1,2-dicloroethane rotamers, but have no idea if there is any program to do that kind of things.

Do you know about some program available for Linux?

I refer to this kind of sketch:

• Do you use Latex? If so, the chemmacros package can do this. – Thomas Jungers Aug 1 '17 at 17:30
• Sure! You can make a standalone document, then convert the pdf to png using ImageMagick (convert file.pdf file.png). There is also a way to compile latex directly to png (run latex, then dvipng), but I have never used it. – Thomas Jungers Aug 1 '17 at 17:46
• My guess is, not enough people need this feature for the developers to implement it. It is however present in proprietary softwares like ChemDraw (which is, of course, not available on Linux). – Thomas Jungers Aug 1 '17 at 17:58
• Some versions of ChemDraw work on Linux via Wine. – andselisk Aug 1 '17 at 21:02
• @santimirandarp How do I put this - if you have ChemDraw already, you are good, Wine is free:) – andselisk Aug 1 '17 at 21:44

You can use GChemPaint, which is available on the repositories of many popular distributions. Among its many components for drawing structures, it has a specific tool for Newman's projections.

You can add H, O and many other elements by simply right-clicking on the molecule, and it even allows you to search your molecule in databases like PubChem and ChemSpider.

A useful video tutorial can be found in spokentutorial.org

# 3.11 To Add a Newman Projection

To add a Newman projection, use the following tool:

This tool allows to add a Newman projection. The changes become permanent only when the mouse button is released.

To add a Newman projection, click on the background. Contrarily to other tools existing atoms are never used by this tool. It creates new atoms of the current element.

When the Newman projection tool is active, the toolbox looks like:

### Options for the main bond

• Bond length

The default length of the new projected bond. This has no influence ion the drawing, but might be important when exporting to a 3d model.

• Bond order

The bond order.

### Options for each atom

• Bonds number

Number of other bonds for the atom.

• First bond angle

The direction of the first bond. Angles are measured counter clockwise from horizontal right.

• Angle between bonds

The angle between two consecutive bonds.

### Warning

This version of GChemPaint does not correctly support Newman projections with eclipsed bonds.

Source: GChemPaint manual, pages 41-43.

You can visit ChemistrySteps.com and use the free drawing tool embedded in the text editor. It doesn't have the ring but you can try using the text and add "O" as the ring. It may not be the best drawing tool but it is free and you can definitely draw many different structures.