chemfig

Reaction schemes

1 Overview¶

Important: As of version 1.8, the following syntax—where ⟨a⟩ is the default angle of the arrows, ⟨c⟩ is the coefficient of their length, ⟨s⟩ is their style, and ⟨p⟩ is the anchor of the first compound—is no longer valid

You should now use a single optional argument

where the default angle, length, and style of the arrows are accessible via the keys arrow angle, arrow coeff, arrow style, and the anchor of the first compound via init anchor.

As shown in this example, debug information is either hidden or displayed with the ⟨key⟩ scheme debug and the value ⟨true⟩ ou ⟨false⟩:

Some comments:

• the \arrow commands draw the arrows;

• everything lying between two \arrow commands is considered a compound. It was decided that all possible settings, whether for arrows or compounds, are controlled by the arguments of the \arrow command, whose syntax may become quite complex;

• arrows are plotted horizontally, this can obviously be modified;

• arrows are plotted on the imaginary line connecting the center of the compounds’ bounding boxes (the red and blue squares are the anchoring points of arrows). This behavior can also be modified;

• debug information is displayed with the scheme debug ⟨key⟩. It consists of:

  • the green label above the bounding boxes is the default name assigned to compounds by chemfig. It follows the series "c1", "c2", etc. Numbering is reset to 1 for every reaction scheme.

  • display of the compounds bounding boxes;

  • the arrows start and end points represented by red points and anchors by blue points;

• the distance from edge to edge between two compounds is defined with the ⟨key⟩ compound sep = ⟨dim⟩. By default this ⟨dim⟩ is 5em;

• finally, the distance between the edges of the compounds and the beginning and end of the arrows is defined with the ⟨key⟩ arrow offset = ⟨dim⟩. By default, this ⟨dim⟩ is 4pt.

Here is the complete list of parameters for the \schemestart macro, their default values, and a brief description. These parameters must be set using the \setchemfig{⟨keys⟩=⟨values⟩} macro.