General Organic Chemistry Flashcards
Types of electron displacement effect
- Inductive Effect
- Resonance Effect
- Hyper Conjugation Effect
- Electromeric Effect
Inductive effect
Partial displacement of electrons in which partial charges will be developed and it is also distance-dependent
Types of inductive effect
+I effect = electron-donating effect
-I effect = electron taking effect
What is the order of +I effect?
CH2->NH->O->COO->3° alkyl > 2°alkyl> 1°alkyl> CH3>T>D>H
What is the order of -I effect?
NF3+>NR3+>NH3+.CH3+.NO2>CN>COH>COOH>F>Cl>Br>I> OR>OH>NH2>Ph>H
Resonanting structure
Various structure obtained after doing resonance
Resonance Hybrid
Actual structure of the compound is called as resonance hybrid
What are the different types of conjugation?
- Normal Conjugation - All the conjugated system
- Extended Conjugation - If the conjugated system is repeated more than once, then it is called an extended conjugation
- Cross Conjugation - If a molecule has 3 parts: A, B, and C such that A and B and A and C are in conjugation, but there is no conjugation between B and C, then the molecule is said to be exhibiting cross conjugation.
Mesomeric Effect
The resonance of the functional group is called as mesomeric effect and generally, it is pπ-pπ resonance.
What is the order of +m effect?
CH2->NH->O->NH2>OH>OR
What is the order of -m effect?
CH2+>NH+>NO2>CN>CHO>COR
Electron density of benzene ring and mesomeric resonance relation?
+m effect showing groups increase the electron density of the benzene ring and the -m effect showing groups decrease the electron density of the benzene ring.
How is stability of carbocation decided?
Stability depends upon the number of α hydrogen.
No. of α hydrogen is equal to the total hyperconjugative structure.
How is the stability of the carboanion decided?
How is the stability of alkenes decided?
More the number of HC structure, more the stability of alkenes.
Aromaticity conditions
Compounds should be planar and hybridisation of each atom should be sp2
It must be cyclic and they should have 4n+2 pi electrons
Monocyclic compounts
All pi bonds can be included in the principle carbon chain
Heterocyclic aromatic compound
Other than carbon, if any other atom is part of a cyclic ring and the compound is aromatic, then it is called as heterocyclic compounds
Anti-aromatic compounds
These compounds follow all the conditions of aromaticity except for Huckel’s rule and hence have 4n pi electrons.
Non-Aromatic Compounds
If one atom of a cyclic ring will be sp3 hybridised, then the compound will be non-aromatic.
Annulenes
Cyclic compounds having conjugated double bonds are called annulenes.
The general formula is CnHn.
What are the stabilities of free radical?
The electron donating group increases the stabilities of free radicals. All the donating effects increase the stability.
What is the basic strength of the amines in the presence of H2O and in gas phase?
2>1>3(PRESENCE OF WATER)
3>2>1(IN GAS PHASE)
Bredt’s rule
In the case of fused bicyclo compounds, the positive charge on the bridge head carbon atom is highly unstable or the hybridisation of a bridge head carbon can never be sp2.
Heat of Hydrogenation and the factor it depends upon
Amount of heat generated when unsaturated hydrocarbon is converted into saturated hydrocarbon.
It is inversely proportional to the stability of alkene and directly proportional to pi bonds.
Heat of Combustion and the factor it depends upon
Amount of heat liberated when a hydrocarbon is burned in the presence of an excess of oxygen.
It is inversely proportional to the stability of the compound and directly proportional to the number of carbon.
