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Bonds and Stereochemistry
This page covers bond tools, stereo displays, and the limits ChemDraft applies to keep a drawing chemically meaningful.
Choose Single Bond to click in empty space or extend from an atom. Its toolbar flyout offers Solid Wedge Bond, Hashed Wedge Bond, Dashed Bond, and Bold Bond. Each is a distinct drawing tool. The default shortcut for Single Bond is M; see Keyboard Shortcuts for the complete registry.
Clicking an atom extends it. Dragging lets you choose an angle; bonds snap to absolute 15° increments by default. Hold Option on macOS or Alt on Windows for a free angle. A bond drag can connect to an atom in a different molecule object, merging the objects and retaining the participating chemistry and attached annotations.
Hover actions provide fast structural changes: 1 adds a single bond, 2 sets a hovered bond to double, and 3 sets it to triple. These actions are target-sensitive: they act on the hovered atom or bond, not on arbitrary page objects. If there is no valid target or insufficient valence, no structure is changed.
A solid wedge and a hashed wedge are stereo bond displays. Use them only where you intend to convey a three-dimensional relationship in a two-dimensional drawing. ChemDraft preserves wedge/hash display in its native document model and treats it as chemistry-relevant data during conversion and export where the format represents it. It does not silently flatten stereo to an ordinary bond.
E/Z geometry is likewise chemical information, not visual styling. Operations that cannot preserve represented stereochemistry must warn or fail. For structure-wide 3D work, see Spin 3D; for file behavior, see File Formats and Compatibility.
One drawing can combine tetrahedral wedge/hash notation with alkene geometry.
In ChemDraft, a dashed single bond denotes a dative or partial interaction, such as a coordination bond or hydrogen bond. It contributes no covalent valence slot to either endpoint. It is therefore not the same thing as a hashed wedge. Dashed display is accepted only on a single bond; a dashed non-single bond cannot be represented as dative chemistry without ambiguity and is handled with a warning by serializers.
Bold bonds are a display tool. They are not a substitute for a stereochemical wedge or hash. See Charges, Radicals, and Dative Bonds for coordination and charge behavior.
ChemDraft resolves aromatic systems against a Kekulé bond-order reading for calculations that need a bond order, including labels, formulas, valence feedback, and structural actions. If a marked aromatic system cannot be resolved, it is not silently treated as certain: the document carries a warning. Explicit hydrogens, literal labels, charges, and dative donors each constrain their own atom.
Check the warnings produced by the operation rather than relying only on how the drawing looks. A wedge, a literal label, a charge, an isotope, or a dashed coordination contact can have format-specific representation limits. ChemDraft’s policy is to preserve the meaning where possible and otherwise identify the loss or refuse the operation. This is particularly important when a receiving application expects a different bond encoding.