Functional Groups

Functional Groups: A combination of atoms that is not part of the alkyl (carbon chain) portion of a molecule Importance of Functional Groups: Change the structure and chemistry of a carbon chain - increase melting points - increase intermolecular attractions - change the solubility of compounds - make them acids or bases Basic Formula: R-X R = alkyl group (Carbon/hydrogen portion) X = functional group

Functional Group Compounds Formula Functional Group Compound Name R-OH Hydroxyl Alcohol

Functional Group Compounds Formula Functional Group Compound Name R-OH Hydroxyl Alcohol R-O-R’ Ether

Functional Group Compounds Formula Functional Group Compound Name R-OH Hydroxyl Alcohol R-O-R’ Ether R-SH Sulfhydryl Thiol

Functional Group Compounds Formula Functional Group Compound Name R-OH Hydroxyl Alcohol R-O-R’ Ether R-SH Sulfhydryl Thiol Rx-NHx Amine

Functional Group Compounds Formula Functional Group Compound Name R-OH Hydroxyl Alcohol R-O-R’ Ether R-SH Sulfhydryl Thiol Rx-NHx Amine Carbonyl Aldehyde

Functional Group Compounds Formula Functional Group Compound Name R-OH Hydroxyl Alcohol R-O-R’ Ether R-SH Sulfhydryl Thiol Rx-NHx Amine Carbonyl Aldehyde Ketone

Functional Group Compounds Formula Functional Group Compound Name R-OH Hydroxyl Alcohol R-O-R’ Ether R-SH Sulfhydryl Thiol Rx-NHx Amine Carbonyl Aldehyde Ketone Carboxyl Carboxylic Acid

Functional Group Compounds Formula Functional Group Compound Name R-OH Hydroxyl Alcohol R-O-R’ Ether R-SH Sulfhydryl Thiol Rx-NHx Amine Carbonyl Aldehyde Ketone Carboxyl Carboxylic Acid Carboxylic Ester

Functional Group Compounds Formula Functional Group Compound Name R-OH Hydroxyl Alcohol R-O-R’ Ether R-SH Sulfhydryl Thiol Rx-NHx Amine Carbonyl Aldehyde Ketone Carboxyl Carboxylic Acid Carboxylic Ester Amide

Alcohols Alcohols are named by replacing the suffix -ane with -anol. If there is more than one hydroxyl group (-OH), the suffix is expanded to include a prefix that indicates the number of hydroxyl groups present (-anediol, -anetriol, etc.). Common Structures: Methanol Ethanol Propanol Isopropanol

Naming Rules for Alcohols 1. The hydroxyl group takes precedence over alkyl groups and halogen substituents, as well as double bonds, in the numbering of the parent chain. 2. In naming a chain with a double bond and a hydroxyl, the double bond is listed first as “en” followed by the alcohol “ol” EX: 2-buten-1-ol

Importance of Hydroxyl Groups 1) Make non-polar alkyl chains polar. - increases intermolecular bonding = higher melting point and boiling point, - increases solubility in water 2) Allows for the formation of bonds between two molecules. - dehydration synthesis

3) Forms alcohols and sugars Importance of Alcohol: - poison = sterilizers/sanitizer - cultural: beverages - economic: booze is money - environmental???: ethanol in gasoline Importance of Sugars: - food and energy - wood and clothing (cotton and rayon)

Metabolism of Alcohol Alcohol is metabolized by several processes or pathways. The most common of these pathways involves two enzymes—alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH). These enzymes help break apart the alcohol molecule, making it possible to eliminate it from the body. First, ADH metabolizes alcohol to acetaldehyde, a highly toxic substance and known carcinogen. Then, in a second step, acetaldehyde is further metabolized down to another, less active byproduct called acetate , which then is broken down into water and carbon dioxide for easy elimination.

Metabolism of Methanol As little as 10 – 15 mL can cause blindness, 30 mL can cause death.

Ethers The two alkyl groups attached to the oxygen are put in alphabetical order with spaces between the names and they are followed by the word ether. The prefix di- is used if both alkyl groups are the same. Ex: methylethyl ether Diphenyl ether dimethyl ether propylbutly ether Diethyl ether

Uses of Ether 1) Anesthetics Ex: Codeine 2) Industrial solvents for non-polar substances 3) Combustion Engines: - Ethyl ether is starter fluid for diesel engines -Methyl t-butyl ether (MTBE) is a gasoline stabilizer/oxygenator

Aldehydes Aldehydes are named by replacing the suffix -ane with -anal. If there is more than one -CHO group, the suffix is expanded to include a prefix that indicates the number of -CHO groups present (-anedial - there should not be more than 2 of these groups on the parent chain as they must occur at the ends). It is not necessary to indicate the position of the -CHO group because this group will be at the end of the parent chain and its carbon is automatically assigned as C-1.

Examples:

Ketones Ketones are named by replacing the suffix -ane with -anone. If there is more than one carbonyl group (C=O), the suffix is expanded to include a prefix that indicates the number of carbonyl groups present (-anedione, -anetrione, etc.).

Uses of Aldehydes and Ketones 1) Sugars 2) Reducing agents: – give electrons away Tollen’s Test Nicotinamide Adenine Dinucleotide (NAD) – used in cellular respiration to produce energy in cells 3) Preservatives: Formaldehyde 4) Solvents: Acetone

Carboxylic Acids Carboxylic acids are named by counting the number of carbons in the longest continuous chain including the carboxyl group and by replacing the suffix -ane of the corresponding alkane with -anoic acid. If there are two -COOH groups, the suffix is expanded to include a prefix that indicates the number of -COOH groups present (-anedioic acid - there should not be more than 2 of these groups on the parent chain as they must occur at the ends). It is not necessary to indicate the position of the -COOH group because this group will be at the end of the parent chain and its carbon is automatically assigned as C-1.

Uses of Carboxylic Acids 1) Flavor: tart tastes: Citric Acid Acetic Acid Malic Acid

Oxalic Acid – found in veggies - can form kidney stones as calcium oxalate

3) Preservatives: Sodium Benzoate 4) Medicine – salicylic acid 2) Acids 3) Preservatives: Sodium Benzoate 4) Medicine – salicylic acid - precursor to aspirin – acetylsalicylic acid

Esters Systematic names of esters are based on the name of the corresponding carboxylic acid. Remember esters look like this: The alkyl group is named like a substituent using the -yl ending. This is followed by a space. The acyl portion of the name (what is left over) is named by replacing the -ic acid suffix of the corresponding carboxylic acid with -ate.

Importance of Esters 1) Flavorings and fragrances

2) Clothing: polyesters

3) Medicine: Absorbable Staples

Amines They are named like ethers, the alkyl (R) groups attached to the nitrogen are put in alphabetical order with no spaces between the names and these are followed by the word amine. The prefixes di- and tri- are used if two or three of the alkyl groups are the same.

Importance: 1) Structure of amino acids  proteins 2) Structure of DNA and RNA 3) Medications: Amphetamines 4) Clothing: Polyamide (nylon)