Organic Chemistry Solvents and Reaction Mechanisms

Vocabulary flashcards covering polar protic and polar aprotic solvents, their chemical structures, formulas, relative polarities, and favored reaction mechanisms.

Polar Aprotic Solvents

Solvents that lack acidic hydrogen atoms and favor bimolecular $S_N2$ and $E2$ reaction mechanisms. Examples include dimethyl sulfoxide ($\text{DMSO}$), dimethylformamide ($\text{DMF}$), acetonitrile ($\text{MeCN}$), hexamethylphosphoramide ($\text{HMPA}$), and acetone ($\text{Me}_2\text{CO}$).

Polar Protic Solvents

Solvents containing acidic hydrogen atoms (capable of hydrogen bonding) that favor unimolecular $S_N1$ and $E1$ reaction mechanisms. Examples include water ($H_2O$), methanol ($\text{MeOH}$), ethanol ($\text{EtOH}$), ammonia ($NH_3$), tert-butanol ($\text{tBuOH}$), and acetic acid ($\text{AcOH}$).

Solvent Polarity Trends and Mechanisms

Diagram showing solvent polarity trends and the specific reaction mechanisms ($S_N2$, $E2$, $S_N1$, $E1$) favored by polar aprotic versus polar protic solvents.

Dimethyl Sulfoxide ($\text{DMSO}$)

A highly polar aprotic solvent with the structural formula containing a sulfur-oxygen double bond attached to two methyl groups.

Dimethylformamide ($\text{DMF}$)

A polar aprotic solvent consisting of a formyl group attached to a dimethylamino group.

Acetonitrile ($\text{MeCN}$ / $CH_3CN$)

A polar aprotic solvent with the chemical formula $CH_3CN$, containing a carbon-nitrogen triple bond.

Hexamethylphosphoramide ($\text{HMPA}$)

A polar aprotic solvent featuring a central phosphorus-oxygen double bond bonded to three dimethylamino groups.

Acetone ($\text{Me}_2\text{CO}$)

A polar aprotic carbonyl solvent consisting of a carbonyl group bonded to two methyl groups.

Acetic Acid ($\text{AcOH}$ / $CH_3COOH$)

A polar protic solvent represented by the chemical formula $CH_3COOH$.

tert-Butanol ($\text{tBuOH}$)

A polar protic alcohol solvent containing a hydroxyl group attached to a tert-butyl carbon group.