Question

is there an easy way to explain the basic concept of organic chemistry? is there an order in which to do things so i can make sense out of it?

Answer 1

Due to catenation property of carbon it is able to form different organic compounds of different number of of carbon atoms along with other atoms like Hydrogen,Oxygen, Nitrogen, Halogens, Sulfur etc.

Organic compounds have been classified from least oxidised to highly oxidised compounds. Different types of organic compounds can be arranged from least oxidised one to the most oxidised one as

Hydrocarbons(Alkane, alkene, Alkyne, aromatic hydrocarbons), alkyl halides(R-X, X = F, Cl, Br and I),amines(R-NH2), notroalkanes(R-NO2), alcohol(R-OH), carbonyl compounds (aldehydes and ketones contain - C=O group), carboxylic acid (R - COOH) and carboxylic acid derivatives like ester(RCOOR^'), anhydride[(RCO)2O], acid chloride (RCOCl), acid amide(RCONH2) etc.

The different types of organic compounds written above have different reactivity due to different types of electron movement of sigma and Pi - bonds. Hence these organic compounds react with different reagents and among each other to form different products. During an organic reaction cleavage of old bonds occurs leading to the formation of reaction intermediates. Now the reaction intermediates form new bonds to form products. Hence the basic concept of organic chemistry can be understood by learning the following thins

(i) Bond cleavage and its types

(ii) Reaction reagents

(iii) Factors effecting reactivity of organic compounds

(iv) Types of organic reactions

(i) Bond cleavage(fission) and its types:

During an organic reaction bonds of the reactants are cleaved to form reaction intermediates which is also called bond fission. Fission reactions are generally of the following types.

(a) Homolytic Bond fission: During homolytic bond fission the electron pairs of a bond are equally distributed to each atom. This leads to the formation of free radical intermediates. e.g.

(b) Heterolytic bond fission: During heterolytic bond fission the electron pair is completely shifted to the more electronegative element. This results in the formation of a cation and an anion. e.g.

(ii) Reaction reagents:

Reaction reagents are atoms/molecules/ions/compounds that react with the reactant to form intermediat and product. Based on the availabiity of free electron reagents are divided in the following types.

(a) Electrophiles(electron loving): These are the reagents that are either positively charged or contain an electron defficient atom like B, Al etc. These reagents react with reactants containing electron or lone pair. e.g. NO2+, R+, BF3, AlCl3, etc.

(b) Nucleophile(nucleus loving): hese are the reagents that are either negatively charged or contain an atom with lone pair of electron like N, P, O, Cl etc. These reagents react with reactants containing a positive charge or an electron defficient atom e.g. OH-, CN- etc.

(iii) Factors effecting reactivity of organic compounds:

The reactivity of organic compounds can be explained by the following types of effects produced due to different types of movement of electron in organic compounds. These are

(a) Inductive effect

(b) Electromeric effect

(c) Mesomeric effect

(d) Hyperconjugation

(e) Resonance effect

(iv) Types of organic reactions:

Based on the structure of the product formed organic reactions can be divided into the following cetegories.

(a) Addition reaction: In addition reaction, the Pi-bond between two atoms is broken and new groups are added to both the atoms. e.g.

(b) Elimination reaction: In elimination reaction two groups are removed from two adjacent atoms and new Pi-bond is formed. e.g.

(c) Substitution reaction: In substitution reaction, one group attached to a single atom is substituted by another group.

By studying all the above terminologies in detail we can understand the basic of organic chemistry properly.