Pentacene Flashcards
(16 cards)
What is the purpose of base in the aldol condensation reaction?
To generate enolate
Hexynide lithium reacts with 6, 13- pentacenequinone via:
Nucleophilic addition to carbonyl
What is the role of tin (II) chloride in synthesis of pentacene derivative?
Provides 2 e- to the benzylic carbocation so that the compound can be rearomatized
Where do you dispose of waste containing tin salts?
Hazardous aqueous liquid acid and basic chemical waste container
What is the stationary phase in the column chromatographic purification of crude pentacene derivative?
Silicon dioxide
The elimination step of the aldol condensation reaction is an example of:
E1cB
How does increasing conjugation effect the energy of absorption?
it decreases it
What is LiHMDS and what is its purpose in the experiment?
Lithium hexamethyldisilazide and is strong non-Nu base. Role is to deprotonate acetylide.
What is the driving force for elimination of water during the reaction to form pentacenequinone?
Increased conjugation achieved once elimination of water proceeds.
What type of electrons are responsible for the photo physical properties of pentacene?
pi
What functional group are expected from IR in pentacenequinone?
C-H stretch (alkene)= 3052.81 cm -1
C=O stretch carbonyl= 1673.90 cm-1
What functional groups are expected from IR in 6,13-Dihexynylpentacene?
C-H stretch(alkane)= 2956.83 cm-1 CtripleC stretch (alkyne)= 2200.53 cm-1
Peak in phthalaldehyde?
~ 2761.59 cm-1
Peak in 1,4 cyclohexadione?
~2917.14 cm-1
What are the reactants for pentacenequinone?
phthalaldehyde and 1,4 cyclohexadione
What are the reactants for dihexynylpentacene?
1-Hexyne and 6,13 pentacenequinone with LiHMDS, THF
