Electron Inductive Effect & General Chemistry Notes PDF

# Electron ## Inductive Effect - **+I:** Atoms or groups donate electron through `(C-C)` - Like: -CH₃ - ALKYL ≤ `CH<sub>3</sub>` < `CH<sub>3</sub>CH<sub>2</sub>` < `CH<sub>3</sub>CH<sub>2</sub>CH<sub>2</sub>` - **-I:** Atom or groups attract electron through `(C-C)` -...

# Electron ## Inductive Effect - **+I:** Atoms or groups donate electron through `(C-C)` - Like: -CH₃ - ALKYL ≤ `CH<sub>3</sub>` < `CH<sub>3</sub>CH<sub>2</sub>` < `CH<sub>3</sub>CH<sub>2</sub>CH<sub>2</sub>` - **-I:** Atom or groups attract electron through `(C-C)` - Like: Halogens - Like: `OH/NH<sub>2</sub>` - Like: `N=O` - Nitro - Like: `(CN)` - Cyano - Like: C=O - Carbonyl - **Chalogens/Nith./OH/SH** - **CO₂/N/S** ## Mosomeric/Resonance effect - Its about shift of (π) electrons ### The types: - **-M:** Halogens, `NO<sub>2</sub>`, `(CN)`, C=O (CarbonyL) - Cyano - **+M:** `-OH/SH/NH<sub>2</sub>` ### The order of priority 1. رابطة ثلاثية. 2. رابطة ثنائية. 3. رابطة احادية . - **(+I/+M) > s** - **(+I) groups** - `(Methyl ` CH₃`/ Ethyl ` C₂H₅`/ Propyl` CH₃CH₂CH₂ )` # General Chemistry ## Resomating structure: - **CH<sub>2</sub>=CH-N=O** - **CH<sub>2</sub>=CH-N<sup>+</sup>=O<sup>-</sup>** - **CH<sub>2</sub><sup>+</sup>-CH=N-O<sup>-</sup>** - **δ<sup>+</sup>CH<sub>2</sub>=CH-N<sup>-</sup>=O** ## Nucleophilic Substitution: - **S-N** - **SN1:** Depends on the concentration of reagents and the nucleophile. The leaving group also depends on its ability to leave. The reaction has two steps, the first step generates carbocation which is unstable and can rearrange. - **SN2:** It depends on the concentration of the nucleophile. The leaving group also depends on its ability to leave. The reaction occurs in one step. The nucleophile attacks the carbocation from the backside. # Factors Affecting Acidity - Acidity increases with increase in eletronegativity of the element. - Acidity increases with the increase in the number of the eletron withdrawing groups. - Acidity of hydrogen increases with increase in stability of conjugate base. - Para-nitro compounds are more acidic than meta-nitro compounds which are more acidic than Alkyl groups. ## Factors Affecting Basicity: - Basicity increases with increase in electron density at the site of protonation (nitrogen). - Groups donating electrons increases the density of the electrons. - Groups withdrawing electrons decreases the density of the electrons. - Double bonds decrease the electron density of the nitrogen. - Cloramine is less basic than methylamine because the Cl atom is an electron withdrawing group. ## Nucleophile - It is a chemical reagent with which a nucleophile attacks the electrophile. It contains lone pairs of electrons and can donate electrons to the electrophile. ## Electrophile - It is a substance which is electron-deficient and can accept electrons from a nucleophile. ## Amines: - **1<sup>st</sup> amine:** `CH₃NH₂` - **2<sup>nd</sup> amine:** `CH₃NHCH₃` - **3<sup>rd</sup> amine:** `(CH₃)₃N` ## Hydrazen: - **Chloto Hydrazen:** `ClNH-NH₂` - **Methyl Hydrazen:** `CH₃NH-NH₂` - **Vinyl Hydrazen:** `NH-NH₂` ## Nucleophile ≡ Base - It contains - Negative charge - A pair of electrons. ## Acid - `RCOOH` ## Factors Affecting Reaction Kinetics: - **Intermediate:** A stable species which is formed during a reaction. It can be isolated and its structure can be identified. - **Transition State:** An unstable species which is formed during the reaction which is not isolated or identified. It can be shown by energy diagram. - **Reaction rate:** The rate with which a reaction is taking place. - **Slow step:** The step that is rate determining. - **Fast step:** The step that is not rate determining. - A reaction progress is moving from reactants to products trough transition state. - If the transition state is higher than the second transition state, the first step is slow. - If the first transition state is lower than the second transition state, the second step is slow. ## Nucleophilic Substitution: - It is a reaction in which a nucleophile attacks an electrophile and results in the substitution of a functional group. - **Leaving Group:** The group that leaves the molecule. - **Carbocation:** An ion in which a carbon atom is electron-deficient. - **Planarity:** Carbocation has a planarity that makes the nucleophile to attack from a backside. ## SN1 reaction: - It is a two-step reaction involving the formation of a carbocation intermediate. It is a first-order reaction because the rate of reaction depends on the concentration of the substrate. - It is a nucleophilic substitution reaction that occurs in two steps, with the first step being the ionization of the substrate to form a carbocation intermediate, and the second step being the attack of the nucleophile on the carbocation. The rate of the reaction is dependent on the concentration of the substrate and is independent of the concentration of the nucleophile for this reason it is called a unimolecular reaction. ## SN2 reaction: - It is a one-step reactions involving an concerted attack of the nucleophile and the leaving group. It is a second-order reaction because the rate of reaction depends on the concentration of both the substrate and the nucleophile. - It is a nucleophilic substitution reaction that occurs in one step, with the nucleophile attacking the substrate at the same time that the leaving group leaves. The rate of the reaction is dependent on the concentrations of both the substrate and the nucleophile. - It is a bimolecular reaction for this reason it is called a second-order reaction. ## Alkyl halides: - It is an organic compound in which one or more hydrogen atoms of an alkane molecule are replaced by halogen atoms. ## Electronic Factors - **Inductive Effect:** It is the influence of the electronegativity of an atom or a group of atoms on the electron density of the molecule. - **Mosomeric effect:** It is the influence of the delocalisation of electrons in a molecule on its electron density. - **More acidic:** If a compound loses a proton easily, it will be more acidic. - **More stable:** If a compound is less reactive, it will be more stable.