Software Developer's Kit - ChemDraw

Send comments on this topic
CDAtomCIPType Enumeration
See Also 

Description

Stereochemistry for atoms.

Members

MemberValueDescription
kCDCIPAtomUndetermined0CIP type undetermined
kCDCIPAtomNone1No CIP type
kCDCIPAtomR2R - when remaining 3 ligands are arranged clockwise in descending order (standard tetrahedral stereochemistry)
kCDCIPAtomS3S - when remaining 3 ligands are arranged counterclockwise in descending order (standard tetrahedral stereochemistry)
kCDCIPAtomPseudoR4R or S is used for pseudo asymmetric atoms (tetrahedral stereochemistry determined by other stereochemical centers)
kCDCIPAtomPseudoS5R or S is used for pseudo asymmetric atoms (tetrahedral stereochemistry determined by other stereochemical centers)
kCDCIPAtomUnspecified6CIP type unspecified.

Remarks

You can create correspondences between atoms in different structures to use in the creation of queries to search a reaction database. You can assign atom mapping in two ways: 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.

Example

See Also