1 / 21

Functional Groups

Functional Groups. A functional group is a small group of atoms that lend characteristic properties to the molecule Properties of the molecule are dictated by the functional groups; allows for systematic study of organic molecules. h n or heat. h n or heat.

issac
Download Presentation

Functional Groups

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Functional Groups A functional group is a small group of atoms that lend characteristic properties to the molecule Properties of the molecule are dictated by the functional groups; allows for systematic study of organic molecules

  2. hn or heat hn or heat Halides: R-X where R is any alkyl group, and X a halogen CH3Cl - chloromethane C6H5Cl - chlorobenzene Synthesis: radical chain reaction between an alkane and a halogen CH4 + Cl2 CH3Cl + HCl Cl2 2Cl• •Cl + CH4  HCl + •CH3 •CH3 + Cl2 CH3Cl + •Cl

  3. Primary alcohol Alcohols: R-OH hydroxyl functional group Nomenclature - use the suffix “ol” CH3-CH2-OH ethanol CH3-CH2-CH2OH 1-propanol Secondary alcohol Tertiary alcohol

  4. Presence of OH group allows hydrogen bonding As the C chain becomes longer the OH group becomes less important Synthesis of alcohols Hydrolysis of a alkyl halide with a strong base OH- + CH3Br  CH3OH + Br- Addition across a double bond CH2=CH2 + H2O CH3CH2OH Charge distribution in ethanol; red indicates negative charge 300 - 400oC 60 - 70 atm

  5. Phenols: hydroxyl group attached directly to an aromatic ring Phenol (C6H5OH) weak acid, Ka = 1 x 10-10; stability of the phenolate ion (C6H5O-)

  6. Oil of thyme Oil of clove

  7. CH3-CH2-OH CH3-CH2-O-CH2-CH3 + H2O + 140oC CH3-CH2-OH H2SO4 180oC 2CH2=CH2 + 2 H2O H2SO4 H2SO4 Ethers: R - O - R C2H5 - O - C2H5 diethylether C6H5 - O - C2H5 ethylphenylether Synthesis: 2 R-OH R - O - R + H2O Kinetics vs thermodynamics

  8. carbonyl group Aldehydes and Ketones aldehyde ketone HCHO: formaldehyde CH3CHO: acetaldehyde CH3COCH3: dimethlyketone (acetone)

  9. O2, catalyst, high temperatures Properties of aldehydes and ketones differ because of the aldehyde H atom CH3CH2OH CH3CHO 1o alcohol aldehyde ethanol acetaldehyde (CH3)2CHOH (CH3)2CO 2o alcohol 2-propanol dimethylketone O2, catalyst, high temperatures

  10. almond and cherries vanilla cinnamon

  11. O2, Mn2+ HCOOH - formic acid (ant venom) CH3COOH - acetic acid (vinegar) Carboxylic acids hydrogen bond - “dimers” Synthesis Catalytic oxidation of aldehydes CH3CHO CH3COOH Carboxylic acids: -COOH functional group

  12. Esters: R-COO- R’ acetic acid + ethanol ethylacetate

  13. Fats (solids) and oils (liquids) are triesters formed from glycerol and three carboxylic acids (fatty acids) Tristearin: animal fatty acid tri-esters CH2OHCHOHCH2OH + 3 CH3(CH2)16COOH glycerol stearic acid Saturated - C-C single bonds Unsaturated - one (mono-unsaturated) or more (polyunsaturated) C=C bonds

  14. ammonia Amines: primary amine (1o) secondary amine (2o) tertiary amine (3o)

  15. CH3NH2 methylamine (CH3)2NH dimethylamine (CH3)3N trimethylamine C6H5NH2 aniline Amines are bases: NicH2+(aq) + 2 NH3(aq)  Nic(aq) + 2 NH4+(aq) Synthesis of amines a) Naturally occurring b) NH3 + CH3Cl  CH3NH2 + HCl nicotine

  16. Amino acids: carboxylic acid containing an amine group Glycine: NH2CH2COOH

  17. cationic form predominant in acidic solutions anionic form predominant in basic solutions dipolar form - zwitterion

  18. Amides: -CONH2- group Formed by reaction between NH3 or 1o or 2o amine and acid

  19. glycine + glycine diglycine + H2O Proteins: polypeptides with CONH linkage between amino acids http://www.cryst.bbk.ac.uk/pps97/course/section3/helix.pdb

More Related