Round 2: Tossup 19

Molecular complexes characterized by this process often use bridged phenylene (“phenyl-een”) or naphthalene groups. This process notably does not occur in compounds like dinitrodiphenic (“di-nitro-di-phenic”) acid or BINAP (“BY-nap”), giving them a form of axial chirality called atropisomerism (“AY-trope-eye-SOM-er-ism”). The prefixes “con” and “dis” describe a set of these (10[1])processes for electrocyclic reactions whose stereochemistry is predicted by Woodward–Hoffman rules. (-5[1])This process alternatively names conformers that sample gauche, staggered, (10[1])and eclipsed geometries. (10[1])This process can be depicted using Newman projections. (-5[1])High energy barriers exist for cis-trans isomerization (10[1])because this process does not occur (10[1])about alkenyl (10[1])carbons. (10[1])For 10 points, name this process (10[1])where a molecule changes torsion angles about certain connections between two atoms. (10[1]0[1])■END■ (0[2])

ANSWER: bond rotation [accept rotation about a bond or word forms; prompt on rotation; prompt on torsion angle changes until read by asking “what physical process causes that?”; reject “molecular rotation”]
<AL, Chemistry> | Packet C - Virginia Tech A, Waterloo A, UCSD A, UBC A
= Average correct buzzpoint

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