Upon start, you will be presented with an empty working space, or canvas. (If you already drawn a molecule and want to start anew, click on the
button, or choose the menu Block > New.)
Start by picking the bond tool,
In the beginning, all atoms you add will be carbons; don't worry, it is better to change them into another element once you have them drawn.
If the molecule contains rings, it is generally better to start with them.
Use the templates provided in the toolbar:
click on the templates button ,
then click on the canvas, once for each ring or structure;
when you are done, click on the button (to keep adding bonds) or the button (to just be able to select).
To draw rings with a single common atom, position the second ring, click and hold; you will see an orange circle around the atom that will be used as connection point; if it's correct, release the mouse button; if not, continue dragging the new ring.
To draw condensed rings, position the black double circle pointer that accompanies the second ring over one of the bonds in the first ring;: when the common bond is highlighted in gray, click.
Then, draw the chains, one bond at a time: click on button (if not already selected) and then on the atom where you want the new atom to be linked. You can also click and drag to position the new bond (at fixed angles). To bond two existing atoms, click on the first one and, without releasing the mouse button, drag to the second atom.
To convert a single bond into double or triple, pick or , and then click on the single bond (you can also add double and triple bonds anew, the same as with single bonds). You can also use and to add stereochemical information to an existing bond, or to draw a new one..
To modify the chemical element of an existing atom, right-click on , choose the element and then click on the atom(s) whose identity you want to change.
If you need other elements, you may write any symbol after picking and clicking on the atom.
Positioning the mouse pointer over each button in the toolbar you will see a floating tooltip with its function.
With you can move (translate) atoms by holding the Alt key and dragging them. (You must have selected them previously.)
You can select a single atom by clicking on and then clicking on the atom.
To select a group of atoms, click on and either
hold the Shift key while clicking on the 2nd ad successive atoms, or
drag the mouse drawing a rectangle; all atoms enclosed will be selected.
To delete an atom, click on it after choosing the tool.
To delete several atoms, pick and click on one atom at a time or drag a rectangular area; all atoms enclosed will be deleted.
To undo the last action, press Ctrl+Z or use the menu, Block > Undo (may be used successively.)
To revert the effect of the last undo, press Ctrl+Shift+Z or use the menu, Block > Redo