ch. 7 conceptual things Flashcards
delocalized electrons are a result of
the p orbital of one atom overlapping the p orbitals of two adjacent atoms
sp2 carbons:
have a + charge OR a double bond
delocalization energy is
the extra stability a compound has due to having delocalized electrons
resonance hybrid vs resonance contributors
the resonance hybrid actually exists and is MORE STABLE than any of its resonance contributors are predicted to be
delocalization energy increases with:
-number of relatively stable resonance contributors
-number of nearly equivalent resonance structures
conjugated double bonds
separated by ONE single bond
isolated double bonds
separated by TWO+ single bonds
conj. double bonds are more or less stable than isolated double bonds?
more stable
explain stability of conj. double bonds in terms of heat of hydrogenation
More stable = less heat released during hydrogenation
for conjugated double bonds: the heat of hydrogenation is LESS than the sum for the individual double bonds
separated charges ___ stability
lower
conjugated dienes have…
delocalized electrons
when lobes interact constructively (+,+) (-,-)…
a pi bonding MO forms
if a structure has delocalized electrons and a bond has partial s character, you can expect that…
it will be shorter than the expected bond length
when lobes interact destructively (+,-)…
a pi anti bonding orbital MO forms
allylic carbon
directly attached to an sp2 carbon
