Nonbonded strain—Increased energy that results when nonadjacent atoms or groups compete for
the same space; also called steric strain.
Nuclear magnetic resonance (NMR) spectroscopy—A technique that measures the alignment of
magnetic moments from certain molecular nuclei with an external magnetic field; can be used to
determine the connectivity and functional groups in a molecule.
Nucleophiles—“nucleus-loving” atoms with either lone pairs or π bonds that can be used to form
new bonds with electrophiles.
Nucleophilic acyl substitution—The substitution of a nucleophile for the leaving group of a
carboxylic acid or carboxylic acid derivative.
Optical isomers—A type of configurational isomers that have different spatial arrangements of
substituents, which affects the rotation of plane-polarized light.
Organic phosphates—Organic molecules—usually nucleotides—that have a variable number of
phosphate groups attached.
Oxidation—Loss of electrons causing an increase in oxidation state; increasing bonds to oxygen or
other heteroatoms in a molecule.
Oxidation state—An indication of the hypothetical charge that an atom would have if all of its
bonds were completely ionic.
Oxidizing agent—An element or compound that accepts an electron from another species, thereby
being reduced in the process.
p-orbital—An atomic orbital that is composed of two lobes located symmetrically about the
nucleus and contains a node.
Paper chromatography—A type of chromatography that uses paper as the stationary phase.
Partitioning—When components in a sample adhere differentially to the mobile and stationary
phases of a chromatographic setup; this causes the different substances to migrate at different
speeds through the stationary phase.