1 Functional Groups: - Carboxylic Acids - Esters - Amides - Aldehydes - Ketones - Amines Mr. Shields Regents Chemistry U17 L02

2 Organic Acids Condensed form is written –COOH –A carbonyl group and a hydroxyl group bonded to same C –Known as a carboxyl group –An organic acid The Carboxyl group is always a terminal functional group

3 Carboxylic acids ionize in water to form a proton and A carboxylate anion A Weak Acid

4 Naming Organic Acids The carboxyl group is a terminal group – no need to give it a number. It’s always on C #1 Drop the –e from the alkane name and add –oic acid Name this compound: Butanoic acid

5 Naming Organic Acids Name this compound: hexanoic acid C-C-C-C-C-COOH

6 - Sharp or noxious smells - polar molecule that can form 2 hydrogen bonds with themselves or with water Physical properties C-C=O OH HO O=C- C C-C=O OH H O H This leads to high B.P. and high solubility in water - 1 st four acids are totally miscible in water

7 Esters Esters are derivatives of Carboxylic acids –Combination of an Acid and an Alcohol –The alcohol portion provides the “Alkyl” part of the ester name

8 Naming Esters Esters are not a terminal group but the carbonyl carbon is considered to be C #1 Name the group attached to the hydroxyl oxygen first (the alkyl group) Next name the carboxylate carbon chain, dropping the – e and adding –oate Written condensed format is RCOOR’

9 Properties Esters have distinctive odors (flowers, flavors etc.) - It’s a f unction of which alcohol is combined with which acid which acid AlcoholAcidEsterFragrance Ethanol Butanoic acid Ethyl butanoate Pineapple Pentanol Ethanoic acid Pentyl ethanoate Banana Octanol Ethanoic acid Octyl ethanoate Orange Methanol Salicylic acid Methyl salicylate wintergreen Methanol Butanoic acid Methyl butanoate apple

10 O CH 3 -C-O-CH 2 -CH 2 -CH 2 -CH 3 butyl ethanoate Ethyl butanoate Name this compound: Name this compound:

11 Amide Like esters the amide functional group is a derivative of carboxylic acids –The -OH is replaced by the amine group The amide group is a terminal group Important biological molecules –Links amino acids together to form proteins

12 Amide Physical Properties -A-Amides have very high BP’s due to strong H-bonding -I-Intermolecular hydrogen bonding possible - H-bonding can occur between N, H and O CH 3 – C=O NH2 CH 3 COOCH 3 CH 3 COOH CH3CONH 2 B.P. (deg. C) BP’s are higher than similar esters and acids

13 Amide Take the name of the alkane with the same number of carbon atoms Drop the –e from the alkane name and add –amide Ethanamide

14 Aldehydes This group is always on a terminal C – so no need to specify location by number Condensed it is symbolized by a -CHO group at the end of the formula Aldehydes have characteristic scents and tastes –Cinnamon, bannana, apple, raspberry flavors are examples

15 Aldehydes To name aldehydes drop the –e from the end of the alkane and add –al; C=O is C #1 Name these two compounds: Methanal (formaldehyde) Butanal

16 Ketones Like the aldehydes the Functional group is the carbonyl group C=O Contains an alkyl group on either side of the C=O –In aldehydes one side is an alkyl group the other is H Often used as a solvent –Acetone is one example

17 Naming Ketones Number the C chain so C=O has the lowest # Drop the final e from the alkane name and add -one Name these compounds: C-C-C-C-C o 3-hexanone 2-pentanone

18 Amines Nitrogen is the functional part of an amine Nitrogen can form three covalent bonds (just like NH 3 ) –One must be to a carbon chain –The other two bonds can be to Carbon and/or H 2 C-C-NH 2 or C-C-N-H or C C-C-N-C C

19 Physical properties of Amines Like ammonia, amines are polar compounds And like ammonia, amines are Bronsted-Lowery Bases - i.e they’re Proton acceptors H :N-R H H+H+

20 Physical properties of Amines -Since amines can act as proton acceptors the reaction with a proton donor like HCl leads to an Ionic Compound H :N-R H HCl + H :N-R H Cl - H +

21 Physical properties of Amines -Amines can H-bond with water -Leads to high water solubility up to about 6C Methyl Amine Ethyl Amine Propyl Amine Butyl Amine Sol (g/100g H 2 0) v. SolTotally miscible Totally Miscible v. sol -A-Amines have very strong odors - Methyl and ethyl amine smells like ammonia -H-Higher MW amines often have a fishy smell -A-Aromatic amines are generally toxic -R-Readily absorbed through skin often with fatal results

22 Naming Amines Need #’s to designate the location of the amine Name your carbon chain as an alkane, drop the – e and add –amine 2-butanamine

23 Some nasty DIAMINES …Yuk!

24 Amino Acids If you have an “-NH 2 ” and a COOH in one molecule it is an amino acid Related to both amines and acids are the Amino Acids GLYCINE (Gly or G) Since the amino group is a proton acceptor and the Carboxylic acid is a proton donor, amino acids are Actually NH 3 + and COO -. Smallest of the 20 amino acids Commonly Found in Proteins Aminoethonaoic acid

25 Another Amino Acid Alanine (Ala; A) O H 3 C-CH-C-OH NH 2 2-aminopropanoic acid