Professor Freedman considers the Merovingians as an example of barbarian kingship in the post-Roman world. In the absence of a strong government, Merovingian society was held together by kinship, private vengeance, and religion. Kings were judged by their ability to lead men in war.  Gregory of Tours believed that the violence characteristic of Frankish society was useful insofar as the kings wielded it to back up threats of supernatural retribution for bad actions.  Professor Freedman ends with a brief summary of the decline of the Merovingians.

Bridged pentavalent carbon structures can be intermediates or transition states of cation rearrangement during S_N1 reactions, and short-lived ion pairs explain net stereochemical inversion. The different perspectives of preparative organic chemists and mechanistic organic chemists on reaction yields are illustrated by a study designed to demonstrate that molecular rotation can be rate-limiting in viscous solvents. “Electrophilic” addition to alkenes is the reverse of E2 or E1 reaction, and its mechanisms can be studied by analogous techniques.

The nature of nucleophiles and leaving groups has strong influence on the rate of S_N2 reactions. Generally a good nucleophile or strong base is a poor leaving group, but hydrogen-bonding solvents can alter nucleophile reactivity. Although amino and hydroxyl groups are poor leaving groups, they may be converted to groups that leave easily, even from bridgehead positions. Designing the preparation of a sugar analogue containing radioactive fluorine shows how understanding the S_N2 mechanism enables PET scanning for medical imaging.

The coincidentally substantial extent of ionic dissociation of water provides an example of Brønsted acidity, or nucleophilic substitution at hydrogen. Relative pK_a values are insensitive enough to solvent that they provide insight on the role of energy-match, overlap, and resonance in ionic dissociation. The titration of alanine in water illustrates the experimental determination of pK_a values and the phenomenon of buffering.

A student provides insight on fractional-order rate laws. Bonds involving atoms with lone-pair electrons are weakened by electron-pair repulsion. Electronegativity differences between atoms make ionic dissociation (heterolysis) easier and radical dissociation (homolysis) harder, although Pauling’s definition of electronegativity makes the logic of the latter effect somewhat circular. The course transitions from free-radical reactions to ionic reactions by discussing solvent properties, in particular the electrostatic properties of alkyl halides and alkanes.