1b Flashcards
what is a carbonyl group
acyl fragment and another group
aka R-C=O
acyl aka i smile : 2 lips )) aka double bond
what hybridisation is seen in a carbonyl group
sp2 hybridised
aka double bond
C: 3 sigma and 1 pi bond
types of carbonyl functional groups
aldehyde
ketone
acyl halide
carboxylic acid
anhydrides
esters
amides
which real life compounds have carbonyl groups
amino acids
aspirin
paracetamol
what is the alpha carbon on a carbonyl group
the C adjacent the one with the couble bond
aka the C next to the one with the double bond
acetone
CH3 - C - CH3
||
O
formaldehyde
H - C - H
||
O
benzophenone
Ph - C - Ph
||
O
acetophenone
Ph - C - Me
||
O
benzaldehyde
Ph - C - H
||
O
acetyl group
Me - C -
||
O
formyl group
H - C -
||
O
benzyl group
Ph - C -
||
O
MO of C=O
- C has 3 sigma 1 pi
3 sp2 for the 2Hs and O
p overlap to give pi - O has 3 sigma and 1 pi
3 sp2 for the 2 lone pairs and C
p overlap to give pi
is the c=o bond shorter or longer than usual
shorter
is the c=o carbonyl group polarised
yess!! it has a dipole moment
c is p+
o is p-
more e- densite on the O
is the carbonyl group an electrophile or a nucleophile
its a electrophile
the electrophile attacks the partially positive C
although electrophiles, aldehydes and ketones can also
be hydrogen bond acceptors
the lone pairs can grap a H+
aldehydes and ketones being hydrogen bond acceptors means they are
soluble in water
they can form hydrogen bonds
what is acetone
a good solvent
can dissolve organic + aqueous compounds
what type of solvent is acetone
polar aprotic
what does ir spec show
shows functional groups as they absorb different frequencies of energy.
if they have a dipole moment
forms a graph
IR spec selection rule
absorbs energy equal to hv
frequency of peak for carbonyl groups
1800 to 1650 cm-1
carbonyl wavelength
5.5 to 6.1
frequency corresponds to the groups
reduced mass
āuā with tail
intesity corresponds to
polarity
