Carbonyls Flashcards
How is the Cyanide Ion formed?
By Heterolytic Fission of HCN forming H+ and NC:-
What is formed when HCN is added to a Carbonyl?
A Hydroxy Nitrile that has gained an extra Carbon
Define Heterolytic Fission
The breaking of a bond in which the two fragments result in having opposite charges
Show a Hydroxy Nitrile being formed from a Carbonyl
Key:
R=Carbon Chain or Hydrogen
——-
2 R groups attached to a C and a O double bonded to the C. The C has a delta+ and the O a delta-
NC- curvy arrow to the delta+ C from opposite the delta- O
And curvy arrow from the bond between the delta- O and delta+ C to the delta- O
Over the arrow——–
NC-C-O (O has - sign) (C still has two R groups)
Curvy arrow from O- to H+
Over the arrow ——-
NC-C-OH (2R groups still on C)
Draw Hydrogen Cyanide reacting with a Carbonyl
Key:
R=Carbon Chain or Hydrogen
——-
2 R groups attached to a C and a O double bonded to the C. The C has a delta+ and the O a delta-
NC- curvy arrow to the delta+ C from opposite the delta- O
And curvy arrow from the bond between the delta- O and delta+ C to the delta- O
Over the arrow——–
NC-C-O (O has - sign) (C still has two R groups)
Curvy arrow from O- to H+
Over the arrow ——-
NC-C-OH (2R groups still on C)
What type of reaction occurs when HCN is added to a Carbonyl?
Nucleophilic Addition (The C=O becomes saturated)
How are carbonyls attractive to nucleophiles?
The asymmetric electron distribution forms a Cδ+
Why are aldehydes more attractive to nucleophiles than ketones?
H is more approachable than a tetrahedral CH3
Alkyl groups allow drift of electrons (making C less δ+ )
What hydrogen bonding occurs with carbonyls?
Carbonyl- water H bonding occurs due to the Oδ-
Intermolecular doesn’t
What feature of carbonyls makes them soluble in water?
Their ability to H bond with water
(Carbonyl’s Oδ- — water’s Hδ+
