Functional Groups PPT PDF

CLASSES OF HYDROCARBONS and FUNCTIONAL GROUPS Prepared by: Prof. Myra B. Ambon, MAT, LPT  Objectives 1. Describe the structure and properties of different functional groups Name and draw structures for aldehydes, ketones, carboxylic acids, esters and amides and oth...

CLASSES OF HYDROCARBONS and FUNCTIONAL GROUPS Prepared by: Prof. Myra B. Ambon, MAT, LPT  Objectives 1. Describe the structure and properties of different functional groups Name and draw structures for aldehydes, ketones, carboxylic acids, esters and amides and other functional groups Prepared by: Prof. Myra B. Ambon, MAT, LPT  Classes of Hydrocarbons Prepared by: Prof. Myra B. Ambon, MAT, LPT Hydrocarbons Prepared by: Prof. Myra B. Ambon, MAT, LPT  a structural unit in a molecule responsible for its characteristic behavior under a particular set of reaction conditions Prepared by: Prof. Myra B. Ambon, MAT, LPT  Alkanes R—H R—X functional group is a hydrogen reaction that takes place is substitution one of the hydrogens is replaced by some other atom or group Prepared by: Prof. Myra B. Ambon, MAT, LPT  Alkanes R—H R—X functional group is a hydrogen reaction that takes place is substitution one of the hydrogens is replaced by some other atom or group H H H H H C C H + Cl2 H C C Cl + HCl H H Prepared by: Prof. Myra B. Ambon, MAT, H H LPT Functional Groups in Hydrocarbons alkanes RH alkenes double bond alkynes triple bond arenes ArH Prepared by: Prof. Myra B. Ambon, MAT, LPT The Key Functional Groups Prepared by: Prof. Myra B. Ambon, MAT, LPT  Functional Groups Functional groups are structural units within organic compounds that are defined by specific bonding arrangements between specific atoms. ✓As ha already been indicated, alkanes are relatively unreactive. ✓For an organic molecule to be reactive it needs something additional. ✓A site of reactivity in an organic molecule is called functional group. Ex. C=C is a functional group. ✓Other functional groups contain elements other than C or H. Like O, N, Cl ,etc. Prepared by: Prof. Myra B. Ambon, MAT, LPT  Functional Groups Class Functional group Alcohol R – OH Ether R — O — R’ Aldehyde O || R—C—H Ketone O || R — C — R’ Carboxylic acid O || — C — OH Ester O || R — C — O — R’ Amine R’ | R — N — R’’ Prepared by: Prof. Myra B. Ambon, MAT, LPT Functional Groups Prepared by: Prof. Myra B. Ambon, MAT, LPT  HALO ALKANES The functional group of alkyl halides is a carbon-halogen bond, the common halogens being fluorine, chlorine, bromine and iodine. Prepared by: Prof. Myra B. Ambon, MAT, LPT  Alkyl Halides Alkyl Halide Properties Alkyl halides are colourless when they exist in pure form. But, bromides and iodides develop colour when exposed to light. Many volatile halogen compounds have a sweet smell. Boiling and Melting Points ✓ Methyl chloride, methyl bromide, ethyl chloride and some chlorofluoromethanes are in the form of gas at room temperature. ✓ Higher members are liquids or solids. ✓ As we know, molecules of organic halogen compounds are polar in nature. ✓ Due to greater polarity and greater molar mass as compared to the parent hydrocarbon, the intermolecular force of attraction is stronger in halogen derivatives. ✓ So, the boiling points of chlorides, bromides and iodides are considerably higher than that of the hydrocarbon with the same molecular mass. ✓ The attraction gets stronger as the size and number of electrons increase. ✓ The boiling points of alkyl halides will decrease in the order RI > RBr > RCl > RF. Prepared by: Prof. Myra B. Ambon, MAT, LPT  Alkyl Halides Density ✓Bromo-derivatives, iodo derivatives and polychloro derivatives of hydrocarbons are heavier than water. ✓The density increases with an increase in the number of carbon atoms, halogen atoms and atomic mass of halogen atoms. Solubility ✓The haloalkanes are less soluble in water. ✓To dissolve haloalkanes in water, energy is required to overcome the attraction between the haloalkane molecule and break the hydrogen bonds between the water molecules for haloalkanes. Prepared by: Prof. Myra B. Ambon, MAT, LPT  Alkyl Halides Chemical Reactions The chemical reaction of haloalkanes can be divided into three categories: 1. Nucleophilic substitution reaction 2. Elimination reaction 3. Reaction with metals Prepared by: Prof. Myra B. Ambon, MAT, LPT Functional Groups Prepared by: Prof. Myra B. Ambon, MAT, LPT  Alkyl Halides The Position of Halogen Atom Along the Chain of Carbon Atom The classification depends on how the halogen atom is positioned on the chain of carbon atoms. Primary alkyl halide Secondary alkyl halide Tertiary alkyl halide Prepared by: Prof. Myra B. Ambon, MAT, LPT  Alkyl Halides Primary Alkyl Halide In this type of haloalkanes, the carbon which is bonded to the halogen family will be attached to only one other alkyl group. It doesn’t matter how much a bulky group is attached to it. Some examples of primary haloalkanes are, ▪ Primary Alkyl Halide Prepared by: Prof. Myra B. Ambon, MAT, LPT  Alkyl Halides Secondary Alkyl Halide In this type of haloalkanes, the carbon atom, which is bonded with the halogen atom, is joined directly to the other two alkyl groups, which can be the same or different. Some examples are, Prepared by: Prof. Myra B. Ambon, MAT, LPT  Alkyl Halides Tertiary Alkyl Halide In this type of haloalkanes, the carbon atom which carries the halogen atom is directly bonded to three alkyl groups. This alkyl group may be a combination of the same or different. Some examples are, Prepared by: Prof. Myra B. Ambon, MAT, LPT  Families of organic compounds and their functional groups Alcohols ROH Alkyl halides RX (X = F, Cl, Br, I) Amines primary amine: RNH2 secondary amine: R2NH tertiary amine: R3N Prepared by: Prof. Myra B. Ambon, MAT, LPT  Alcohol In the alcohol functional group, a carbon is single-bonded to an OH group (the OH group, by itself, is referred to as a hydroxyl). Except for methanol, all alcohols can be classified as primary, secondary, or tertiary. In a primary alcohol, the carbon bonded to the OH group is also bonded to only one other carbon Prepared by: Prof. Myra B. Ambon, MAT, LPT  Functional Groups alcohol, phenol and thiol Note that the definition of a phenol states that the hydroxyl oxygen must be directly attached Prepared to B. Ambon, MAT, by: Prof. Myra LPT  Functional Groups Amines are characterized by nitrogen atoms with single bonds to hydrogen and carbon. Prepared by: Prof. Myra B. Ambon, MAT, LPT  Amines Just as there are primary, secondary, and tertiary alcohols, there are primary, secondary, and tertiary amines. Ammonia is a special case with no carbon atoms. Prepared by: Prof. Myra B. Ambon, MAT, LPT Functional Groups Prepared by: Prof. Myra B. Ambon, MAT, LPT  Families of organic compounds and their functional groups Epoxides C C O Ethers ROR' Nitriles RC N Nitroalkanes RNO2 Thiols RSH Prepared by: Prof. Myra B. Ambon, MAT, LPT  Functional Groups ether functional group, a central oxygen is bonded to two carbons. Prepared by: Prof. Myra B. Ambon, MAT, LPT  Many classes of organic compounds contain a carbonyl group O O C C R Carbonyl group Acyl group Prepared by: Prof. Myra B. Ambon, MAT, LPT  Functional Groups There are a number of functional groups that contain a carbon-oxygen double bond, which is commonly referred to as carbonyl Ketones and aldehydes are two closely related carbonyl-based functional groups that react in very similar ways. Prepared by: Prof. Myra B. Ambon, MAT, LPT  Functional Groups In a ketone, the carbon atom of a carbonyl is bonded to two other carbons. In an aldehyde, the carbonyl carbon is bonded on one side to a hydrogen, and on the other side to a carbon. The exception to this definition is formaldehyde, in which the carbonyl carbon has bonds to two hydrogen. Prepared by: Prof. Myra B. Ambon, MAT, LPT  Many classes of organic compounds contain a carbonyl group O O C C R H Carbonyl group Aldehyde Prepared by: Prof. Myra B. Ambon, MAT, LPT Functional Groups Prepared by: Prof. Myra B. Ambon, MAT, LPT  Many classes of organic compounds contain a carbonyl group O O C C R R' Carbonyl group Ketone Prepared by: Prof. Myra B. Ambon, MAT, LPT Functional Groups Prepared by: Prof. Myra B. Ambon, MAT, LPT Functional Groups Prepared by: Prof. Myra B. Ambon, MAT, LPT  Rules in Naming Aldehydes 1. Identify the longest chain of carbons which contains the carbonyl group (PREFIX- ANE+AL). And when numbering the parent chain, the carbonyl group gets the lowest possible number, therefore it is always 1 and therefore is not included in the name. 2. Names and position of the substituents. Prepared by: Prof. Myra B. Ambon, MAT, LPT  Rules in Naming Ketones 1. Identify the longest chain of carbons which contains the carbonyl group (PREFIX-#- ANE+ONE). And when numbering the parent chain, the carbonyl group gets the lowest possible number. 2. Names and position of the substituents. Draw the structures of: a) pentan-2-one; b) hexan-2-one; c) butane Prepared by: Prof. Myra B. Ambon, MAT, LPT  Test Yourself Give the condensed structure of the following amines: a) propanone b) propanal c) heptan-3-one d) octanal Answer a) CH3COCH3 b) CH3CH2CHO c) CH3CH2CH2CH2COCH2CH3 or CH3(CH2)3COCH2CH3 d) CH3CH2CH2CH2CH2CH2CH2CHO or CH3(CH2)6CHO Prepared by: Prof. Myra B. Ambon, MAT, LPT  Many classes of organic compounds contain a carbonyl group O O C C R OR' Carbonyl group Ester Prepared by: Prof. Myra B. Ambon, MAT, LPT Functional Groups Prepared by: Prof. Myra B. Ambon, MAT, LPT  Many classes of organic compounds contain a carbonyl group O O C C R OH Carbonyl group Carboxylic acid Prepared by: Prof. Myra B. Ambon, MAT, LPT Functional Groups Prepared by: Prof. Myra B. Ambon, MAT, LPT NAMING CARBOXYLIC ACIDS AND ESTERS Both carboxylic acids and esters contain a carbonyl group with a second oxygen atom bonded to the carbon atom in the carbonyl group by a single bond. In a carboxylic acid, the second oxygen atom also bonds to a hydrogen atom. In an ester, the second oxygen atom bonds to another carbon atom. The names for carboxylic acids and esters include prefixes that denote the lengths of the carbon chains in the molecules. Prepared by: Prof. Myra B. Ambon, MAT, LPT NAMING CARBOXYLIC ACIDS AND ESTERS 1. Carboxylic acid - Identify the longest chain of carbons which contains the carbonyl group (PREFIX-ANE+OIC ACID). Ester -Identify the longest chain of carbons which contains the carbonyl group (PREFIX- ANE+OATE). 2. Names and position of the substituents. Prepared by: Prof. Myra B. Ambon, MAT, LPT NAMING CARBOXYLIC ACIDS AND ESTERS Prepared by: Prof. Myra B. Ambon, MAT, LPT  Example Draw the structures of: a) 3-methylpentanoic acid; b) ethyl ethanoate; c) propyl 2- chlorobutanoate a) 3-methylpentanoic acid; b) ethyl ethanoate c) propyl 2-chlorobutanoate Prepared by: Prof. Myra B. Ambon, MAT, LPT  Test Yourself Name the following compounds: a) CH3CH2COOH b) CH3CH2CH2CH2COOCH2CH3 c) BrCH2(CH2)2COCH3 d) (CH3)2CH(CH2)6COOH Answer a) propanoic acid b) ethyl pentanoate c) methyl 4-bromobutanoate d) 9- methylnonanoic acid Prepared by: Prof. Myra B. Ambon, MAT, LPT  Many classes of organic compounds contain a carbonyl group O O C C R NH2 Carbonyl group Amide Prepared by: Prof. Myra B. Ambon, MAT, LPT  Functional Groups Amides are molecules that contain nitrogen atoms connected to the carbon atom of a carbonyl group. Identify the longest chain of carbons which contains the carbonyl group (PREFIX- ANE+AMIDE). Prepared by: Prof. Myra B. Ambon, MAT, LPT  Naming Amides 1. Identify the longest chain of carbons which contains the carbonyl group (PREFIX-ANE+AMIDE). 2. Names and position of the substituents. Example: Give the condensed structures of: a) decanamide; b) hexanamide; c) 2-chloroethanamide Solution a) Its condensed structure is: CH3(CH2)8CONH2 b) Its condensed structure is: CH3(CH2)4CONH2 c) Its condensed structure is: ClCH2CONH2 Prepared by: Prof. Myra B. Ambon, MAT, LPT  Test Yourself Name the following compounds: a) CH3(CH2)2CONH2 b) BrCH2(CH2)3CONH2 c) (CH3CH2)2CH(CH2)5CONH2 Answer a) butanamide b) 5-bromopentanamide c) 7-ethylnonanamide Prepared by: Prof. Myra B. Ambon, MAT, LPT  Many classes of organic compounds contain a carbonyl group O O C C R NH2 Carbonyl group Amide Prepared by: Prof. Myra B. Ambon, MAT, LPT Functional Groups Prepared by: Prof. Myra B. Ambon, MAT, LPT Prepared by: Prof. Myra B. Ambon, MAT, LPT