Software Developer's Kit - ChemDraw

Send comments on this topic
Stereochemistry Property
See Also 

Description

Member of ChemDraw Control.Atom.

Sets and returns the absolute stereochemistry of this atom

Property type

Read-write property

Syntax

Visual Basic
Public Property Stereochemistry() As CDAtomCIPType

Return Type

Remarks

Absolute stereochemistry is calculated for tetrahedral atoms and double bonds according to the Cahn-Ingold-Prelog (CIP) priority rules.  The CIP rules are designed to order ligands by their priority and determine a descriptor based on the orientation of the ordered ligands in space. A ligand is an entity attached to a stereocenter.  For example, a tetrahedral carbon has four ligands corresponding to its four substituents.  When a tetrahedral carbon is in a ring, it still has four ligands: the two ligands outside the ring, a third consisting of the ring "unpeeled" clockwise, and a fourth consisting of the ring "unpeeled" counterclockwise.

If this property is absent then the bond is treated as having undetermined stereochemistry. 

Example

'Declares variables
 Dim myAtom As ChemDrawControl10Ctl.Atom
'Checks that there is an atom loaded in the variable
 If  Selection.Atoms.Count < 1 Then
     Exit Sub
 End If

'Reads and sets this property
 Private Sub cmdStereoChemistry_Click() 
      myAtom.StereoChemistry = val(text1.text) 
      Text2.text = myAtom.StereoChemistry  
 End Sub

See Also