Fig. 29
Non-standard bond types in PubChem. a Ionic bond between sodium and sulfur in sodium thiopental (CID 23665410); b Complex bond between nitrogen atoms and Fe(II) represented as Fe2+ in heme b (CID 4973); c Dative bond between boron and oxygen in boron trifluoride diethyl etherate (CID 517922). Contrary to other annotations of this bond type, in PubChem, the participating atoms do not get assigned charges