CHEM 251 1st Edition Lecture 21 Outline of Last Lecture I. Clicker QuestionII. Metal Cations in WaterIII. OxyanionsOutline of Current Lecture IV. Clicker QuestionsV. Lewis Acids and BasesVI. Predicting Acidity/BasicityVII. ReactivityVIII. Choosing SolventIX. Frustrated PairsCurrent LectureX. Clicker Questionsa. What is the strongest Lewis Acid?(A) AlBr3 (B) AlBr4- (C) PBr3 (D) CBr4XI. Lewis Acids and Basesa. Lewis acid-electron pair acceptori. Bronsted acids not usually Lewis acidsii. Electrophilesiii. Metal cationsiv. Empty orbitals accessibleb. Lewis base-electron pair donatori. Anything w/ lone pairii. Filled non-bonding orbitalsiii. Bronsted basesiv. Nucleophilesv. Neutral, anionicXII. Predicting Lewis acidity/basicitya. Lone pairs => likely a baseb. Unfilled octet => likely an acidThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.c. Metal cation w/ noble gas config => acidXIII. Reactivity: Lewis Pairsa. Acids react w/ basesb.c. Cationic Lewis Pairsi. Lone pairs on O donate into Na+ s and p orbitalsii. Transition metal cases:1.d. Relative Acidity/Basicityi. Stronger lewis bases: more e- donating groups, stronger Bronsted basesii. Stronger acids: more electron w/drawing groupsXIV.Choosing Solventsa. In water, water usually best lewis baseb. Polar protic/aprotic often lewis basicc. In the absence of lewis base, any electron pair will doi. Ex: borane in equilibrium w/ diboraneXV. Frustrated Lewis Pairsa. When extreme steric bulk is presentb. Acid and base not quenched c. Allows each element to react; H2
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