1 / 30

Organic Chemistry I

Organic Chemistry I. University of Lincoln presentation. This work is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 2.0 UK: England & Wales License. Organic chemistry. C is a small atom It forms single, double, and triple bonds

carnig
Download Presentation

Organic Chemistry I

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. Organic Chemistry I University of Lincoln presentation This work is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 2.0 UK: England & Wales License

  2. Organic chemistry • C is a small atom • It forms single, double, and triple bonds • It is intermediate in electronegativity (2.5) • It forms strong covalent bonds with C, H, O, N, S and some metals What’s so important about Carbon Chemistry? >7 or 10 or 30! million Organic Compounds (depends on the source) 1.5 million Inorganic Compounds Lubricants, Cosmetics, Fragrances, Pigments, Dyes, Inks, Adhesives, Explosives, Detergents, Surfactants, Emulsifiers, Coolants, Photographic agents, Forensic chemicals, Plastics, Drugs, …. And most important!! Is the base of the Chemistry of Life This work is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 2.0 UK: England & Wales License

  3. Carbon has 4 valence electrons Methane Methane Neon Stable Octet required Covalent bonding – Atoms share electrons This work is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 2.0 UK: England & Wales License

  4. Problem • bonding by 2s and 2p atomic orbitals would give bond angles of approximately 90°. • Instead we observe bond angles of approximately 109.5°, 120°, and 180° • Solution • hybridization of atomic orbitals • 2nd row elements use sp3, sp2, and sp hybrid orbitals for bonding This work is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 2.0 UK: England & Wales License

  5. C(6) – 1s2, 2s2, 2px1, 2py1, 2pz0 Lowest energy state C(6) – 1s2, 2s1, 2px1, 2py1, 2pz1 Excited state 4 sp3 2py 2px 2pz 4 x sp3 2s This work is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 2.0 UK: England & Wales License

  6. Hybridization of orbitals • (L. Pauling) • “The combination of two or more atomic orbitals forms a new set of atomic orbitals, called hybrid orbitals” • We deal with three types of hybrid orbitals • sp3 (one s orbital + three p orbitals) • sp2 (one s orbital + two p orbitals) • sp (one s orbital + one p orbital) • Overlap of hybrid orbitals can form two types of bonds depending on the geometry of overlap • σ bonds are formed by “direct” overlap • π bondsare formed by “parallel” overlap This work is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 2.0 UK: England & Wales License

  7. sp3 Hybrid Orbitals • each sp3 hybrid orbital has two lobes of unequal size • the sign of the wave function is positive in one lobe, negative in the other, and zero at the nucleus • the four sp3 hybrid orbitals are directed toward the corners of a regular tetrahedron at angles of 109.5° 109.5o An sp3 orbital Four tetrahedral sp3 orbitals This work is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 2.0 UK: England & Wales License

  8. Methane is Tetrahedral Sigma bonds formed by overlap of sp3 and 1s orbitals 109.5o Methane Sp3 hybridized carbon 4 equivalent C-H bonds (s-bonds) This work is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 2.0 UK: England & Wales License

  9. sp Hybrid Orbitals 2 • the axes of the three sp2 hybrid orbitals lie in a plane and are directed toward the corners of an equilateral triangle • the unhybridized 2p orbital lies perpendicular to the plane of the three hybrid orbitals This work is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 2.0 UK: England & Wales License

  10. Bonding in Ethylene This work is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 2.0 UK: England & Wales License

  11. sp Hybrid Orbitals • Two lobes of unequal size at an angle of 180° • The unhybridized 2p orbitals are perpendicular to each other and to the line created by the axes of the two sp hybrid orbitals This work is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 2.0 UK: England & Wales License

  12. This work is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 2.0 UK: England & Wales License

  13. This work is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 2.0 UK: England & Wales License

  14. Organic Compounds Aldehydes Halocarbons Alcohols Hydrocarbons Ketones Nitriles Ethers Nitrocompounds Acids Amines Esters Amides This work is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 2.0 UK: England & Wales License

  15. This work is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 2.0 UK: England & Wales License

  16. Alkanes • Chemical formula CnH2n+2 n = 1, 2, 3, … • CH4, methane, simplest one • C2H6, ethane • All have –ane ending • Follow a pattern This work is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 2.0 UK: England & Wales License

  17. Properties of Alkanes This work is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 2.0 UK: England & Wales License

  18. Cycloalkanes Cycloalkanes have higher bpt/mpt than straight chain alkanes with the same number of carbon atoms • Carbon atom chains in form of rings • Name: cyclo + alkane name (i.e. Cyclobutane) Cyclopropane This work is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 2.0 UK: England & Wales License

  19. Isomerism • Isomers: compounds with same molecular formula but different structural formulas • Differences in structure may give rise to differences in chemical and physical properties • To name them choose the longest unbroken chain, and number the alkyl groups to obtain the lowest possible number (2, methylpropane) Butane Isobutane This work is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 2.0 UK: England & Wales License

  20. C4H10 – has two isomers, n-butane and isobutane (2-methylpropane) Isobutane 2, methylbutane Has the same molecular formula as n-pentane, C5H12 2, 2 dimethylpropane Isopentane They all have different Physical Properties, Mpt, Bpt, densities Neopentane This work is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 2.0 UK: England & Wales License

  21. alkene Ethane Bromoethane Reactions of Alkanes ■ Combustion ■ Dehydrogenation ■ Halogenation This work is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 2.0 UK: England & Wales License

  22. IUPAC rules This work is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 2.0 UK: England & Wales License

  23. 2-Methylbutane This work is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 2.0 UK: England & Wales License

  24. Alkenes • Alkene: Unsaturated hydrocarbon that contains one or more carbon-to-carbon double bonds • General formula of CnH2n • All have –ene ending • Simplest: ethylene, C2H4 3, methyl-1,4-pentadiene 1,3-Butadiene 1-Butene This work is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 2.0 UK: England & Wales License

  25. Reactions of Alkenes ■ Addition reactions Alkyl Halides Alkyl hydrogen Sulphate Alcohols Dihaloalkanes This work is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 2.0 UK: England & Wales License

  26. Cyclohexene Cyclohexane ■ Hydrogenation (another addition reaction) ■ Oxidation ■ Combustion This work is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 2.0 UK: England & Wales License

  27. ■ Polymerisation Polymers are large molecules containing many identical repeating units (100-1000000) Polymerisation reaction is a repetition reaction which combines many small molecules of monomer (alkene) to form a polymer Addition polymer is a polymer in which the monomer simply add together with no other products formed besides polymer polyethylene ethylene polypropylene propylene poly(vinylchloride), PVC vinyl chloride teflon tetrafluoroethene Styrene polystyrene This work is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 2.0 UK: England & Wales License

  28. Alkynes • Alkyne: hydrocarbon that contains one or more carbon-to-carbon triple bonds • General formula of CnH2n–2 • All have –yne ending • Simplest: acetylene, C2H2 Acetylene This work is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 2.0 UK: England & Wales License

  29. Reactions of Alkynes ■ Combustion Alkynes are high energy compounds Welding gas ■ Addition reactions This work is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 2.0 UK: England & Wales License

  30. Acknowledgements • JISC • HEA • Centre for Educational Research and Development • School of natural and applied sciences • School of Journalism • SirenFM • http://tango.freedesktop.org This work is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 2.0 UK: England & Wales License

More Related