Skip to main content
Fig. 32 | Journal of Cheminformatics

Fig. 32

From: PubChem chemical structure standardization

Fig. 32

Functional Group Standardization III. If not mentioned otherwise, hydrogen atoms are as depicted, and wildcard asterisks (*), representing connected any atoms, can be hydrogen atoms. Connected carbon atoms are shown without labels and should not be confused with ‘any’ connections. Parenthesis indicates terminal atom. Numbers above arrows are transformation indices for respective standardization rules (see the text for the description of transformation indices). a Penta-valent nitrogen connected to terminal nitrogen (triple bond) and carbon, nitrogen or oxygen (double bond). b Penta-valent nitrogen connected to terminal oxygen or sulfur (double bond) and non-terminal carbon (triple bond). c Nitro group and nitrate (penta-valent representation). d Single-bonded atoms adjacent to nitrogen are (not necessarily terminal) carbon. e Covalent single bond between penta-valent nitrogen and oxygen or sulfur replaced by ionic bond. f, g Covalent single bond between penta-valent nitrogen and halogen replaced by ionic bond. h, i Covalent single bond between tetra-valent nitrogen and halogen replaced by ionic bond. j Double bond between tetra-valent nitrogen and boron replaced by dative bond. k, l Nitrogen without implicit hydrogens. m Nitro group (tetra-valent representation)

Back to article page