1 / 17

CH0004: Foundation Chemistry 2004-2005 ORGANIC REVISION NOTES Dr. David Johnson Room E207a

CH0004: Foundation Chemistry 2004-2005 ORGANIC REVISION NOTES Dr. David Johnson Room E207a Department of Chemistry & Materials Manchester Metropolitan University phone: 247 1422 email: d.johnson@mmu.ac.uk . Organic Chemistry: “The Chemistry of Carbon”

tuyet
Download Presentation

CH0004: Foundation Chemistry 2004-2005 ORGANIC REVISION NOTES Dr. David Johnson Room E207a

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. CH0004: Foundation Chemistry 2004-2005 ORGANIC REVISION NOTES Dr. David Johnson Room E207a Department of Chemistry & Materials Manchester Metropolitan University phone: 247 1422 email: d.johnson@mmu.ac.uk

  2. Organic Chemistry: “The Chemistry of Carbon” At this level – we will only consider covalent molecules consisting of C H O & N (and halides) Within stuctures – the number of bonds to these atoms is always as follows: C 4 bonds N 3 bonds O 2 bonds H 1 bond

  3. Hydrocarbons: Molecules consisting entirely of C and H (a) Aliphatic 1. Saturated (linear or ring) (means that all bonds taken by single bonds) Alkanes 2. Unsaturated (linear or ring) (some c-c double or triple bonds present) Alkenes Alkynes (b) Aromatic Conjugated system of single and double bonds - usually in a ring e.g. benzene

  4. Alkanes: CnH2n+2 for linear compounds a prefix for the carbon number + “ane” Methane = 1 carbon Ethane = 2 carbons Propane = 3 carbons 4. But 5. Pent 6. Hex 7. Hept 8. Oct 9. Non 10. Dec Alkenes: CnH2n for linear compounds Same prefixes +”ene” e.g. hexene for 6 carbons Alkynes: CnH2n-2 for linear compounds Same prefixes +”yne” e.g. nonyne for 9 carbons

  5. Side Chains: Take the name of the parent alkane e.g. –CH3 = methyl -C4H9 = butyl etc Generally known as –alkyl groups given the general symbol of R Positions: The position of side chains or double bonds is identified by a numbering system: i. idenify the longest carbon chain - then use the correspeonding prefix ii. name the substituent groups iii. identify position[s] by number (take the lowest possible) iv. Use ene or yne to identify presence of unsaturated bond[s]

  6. Ways of writing it down: Name: hexane Molecular formula: C6H14 Molecular structure: CH3 – CH2 – CH2 – CH2 – CH2 – CH3 “Stick Stucture” Functional Groups: Alcohol (ROH) named by adding -ol Halide (R-Cl) named by inserting –chloro same from fluoro, bromo and iodo Acid (RCOOH) named by adding –oic acid Amine (RNH2) named by inserting –amino Aldehyde (RCHO) named by adding –al Ketone (R1R2CO) named by adding -one Ether (R1OR2) named by inserting –oxy Ester (R1COOR2) named by using -oate Alkene (double bond) named by using –ene Alkyne (triple bond) named by using -yne

  7. Examples of Nomenclature - Unsaturated Hydrocarbons: But-1-ene But-2-ene Pent-1-yne Pent-2-yne 4-methylpent-2-ene Non-3-ene-5-yne Buta-1,3-diene

  8. Examples of Nomenclature - Functional Groups: 2-chlorobutane 2-bromo-4-methylhexane propan-1-ol propan-2-ol propanoic acid 2-aminobutane ethanoic acid 4,6-dimethylheptanal

  9. 1-aminobutane hexan-3-one Ordering: Double bonds before triple bonds in terms of priority - but both of these take priority over other functional groups. The lowest priority are chain substituents (e.g. alkyl groups or halides) which go in alphabetical order trans 4-chloropent-2-ene 4-chloro-2-methylpent-2-ene 4-chloro-2-methylhex-2-ene-5-yne

  10. Ring Systems (examples): Benzene Cyclohexane Cyclopentane Cyclohexene Phenol Aniline Benzoic Acid Benzaldehyde Styrene

  11. Ring Systems: Chlorobenzene Methylbenzene 1,2-dimethylbenzene 1,3-dimethylbenzene 1,4-dimethylbenzene hexachlorobenzene bromo-3-chloro- benzene

  12. Isomers: Essentially – the same overall molecular formula but the atoms arranged in either a different way (structural isomerism) or different molecular geometry or orientation (steroisomerism) Structural Isomerism: i. chain ii. positional iii. functional group Stereo-Isomerism: i. geometrical (cis-trans) ii. conformational (e.g. cyclohexane) iii. optical (involving a chiral centre) Examples – see later

  13. Chain Isomerism: • different arrangement of chain backbone • examples with naming: • C6H14 • i. n-hexane • ii. 2-methylpentane • iii. 3-methylpentane • iv. 2,2-dimethylbutane • v. 2,3-dimethylbutane

  14. Positional Isomerism: • different position of functional group within chain • Propan-1-ol • Propan-2-ol • Functional Group Isomerism: • different functional groups but still having same overall molecular formula • Butanoic acid C4H8O2 • But-2-ene-3,4-diol

  15. Geometrical Isomerism (“cis” / “trans”): • different orientations across a double bond • C6H12 • cis hex-3-ene • trans hex-3-ene • Conformational Isomerism: • different orientations of a ring structure such as cyclohexane (again C6H12) • Cyclohexane Chair form Boat Form • stick diagram

  16. Optical Isomers: = “Chiral Centre” A carbon atom bonded to 4 different groups The 2 isomers are actually mirror images of each other 1 1 4 4 2 2 3 3 Mirror Plane

  17. Optical Isomers: The 2 “mirror image” isomers are known as enantiomers 2 forms labelled as D (or “+”) and L (or “-”) standing for the latin dextro and laevo - referring to the fact that they are identified by how they interact with light in an instrument known as a polarimeter. Examples of chiral molecules: 2-hydroxypropanoic acid (lactic acid) 3-methylhexane

More Related