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Gr-8. Double bonds, dative bonds, and charge-separated forms.(GRAPHICAL REPRESENTATION STANDARDS FOR CHEMICAL STRUCTURE DIAGRAMS **)
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Pure and Applied Chemistry
- Article date:
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February 1, 2008
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Copyright informationCOPYRIGHT 2008 International Union of Pure and Applied Chemistry. This material is published under license from the publisher through the Gale Group, Farmington Hills, Michigan. All inquiries regarding rights should be directed to the Gale Group. (Hide copyright information)
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"The nitro problem" is one of the most familiar issues in chemical informatics: How should a nitro group be best represented? Experimentally, the two oxygen atoms are equivalent, so it would make sense to depict them symmetrically. However, any way to depict them symmetrically will either violate the popular "octet rule" or force a double positive charge on the nitrogen atom. Conversely, any attempt to honor the octet rule results in oxygen atoms that appear to be non-equivalent.
Similar problems arise for molecules based on sulfur, phosphorus, and related elements. Furthermore, all of these are fairly common functional groups, and cannot readily be pushed aside as ...
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