EFN-313 Lífræn efnafræði

1. EFN-313 Lífræn efnafræði 11. kafli

2. “The most important hypothesis in all of biology…is that everything that animals do, atoms do. In other words, there is nothing that living things do that cannot be understood from the point of view that they are made of atoms acting according to the laws of physics.” Richard Feynman (1918-1988)

3. Lífræn efni byggjast öll á kolefni • C, CO, CO2 og CO3 teljast ólífræn • Önnur C sambönd kallast lífræn • Annaðhvort sameindir eða sameindajónir • Óendanlega mörg lífræn efni til, á öllum formum með mismunandi eiginleika.

4. C-atóm eru einstök • Mynda óskautað samgild tengi við Vetni • Mynda samgild tengi sín á milli og mynda langar keðjur • Mynda samgild tengi við aðra málmleysingja t.d. P,O,N,S og halogena • C-C og C-H tengi eru óskautuð (nonpolar)

5. Raun lögun etan sameindar Fjögur sp3 hybridised orbitals mynda ferflötung sp3 hybridised orbitals frá 2 C atómum geta skarast og myndað C-C σ-tengi Each sp3 orbital contributes one electron to form C-C[C..C] C-C s bond

6. sp3 svigrúmablanda (rafeindir) flýr eins langt frá kjarnanum og hægt er og tengist í þær áttir.

7. Carbon sp3 orbitals can overlap with Hydrogen 1s orbitals to form Carbon-Hydrogen s bonds Each sp3 orbital contributes one electron; each s orbital contributes one electron to form C-H [C..H] sbonds: symmetrical about the bond axis

8. C-C N-N O-O Bond Dissociation Energy (kJ mol-1) 348 163 157 • Carbon-Carbon bonds: especially Sterk samgild tengi • Kolefni: Einstakt, myndar catenate [Keðjur] • Forms molecules composed of C-C bonds Línulaga/Linear Greinótt/Branched Hring/Cyclic

9. Organic molecules = Carbon-based molecules • Organic chemistry = Chemistry of carbon-based molecules Some properties of organic molecules • Stability: composed of stable C-C covalent bonds • Defined molecular structures • Defined three-dimensional shapes

10. Organic chemicals are universal • Biological matter • Plants • Animals • Microbes • Geological matter • Fossil Fuels • Other Organic Chemicals Atmospheric and cosmic matter Manufactured products

11. Sugars Proteins Fats & oils Vitamins DNA & RNA Wood Natural rubber Essential oils Natural fibres Antibiotics Fermentation products Natural flavours Natural fragrances Plant & microbial products Bio-matter Biological organic chemicals

12. Organic chemicals in manufactured products Imaging agents Medicines Veterinary medicines Disinfectants Bio-active products Herbicides Antiseptics Pesticides Fertilizers Fungicides Plant growth hormones

13. Organic chemicals in manufactured products Plastics Coatings & lacquers Fibres & clothings Paper Materials Films Packaging Wound dressings Medical implants

14. Organic chemicals in manufactured products Fibre Fats & Oils Vitamins Sugars Foods Flavourings Dietary supplements Anti-oxidants Colourants Methanol/Ethanol “Petrol” “Diesel” Fuels Peat/Turf Coal LPG Natural gas

15. Lubricants Cosmetics Fragrances Pigments Dyes Inks Adhesives Explosives Detergents Surfactants Emulsifiers Coolants Photographic agents Anti-scalants Forensic chemicals Liquid crystal displays Organic chemicals in manufactured productsMiscellaneous

16. Hydrocarbons - Kolvetni • Kolvetni eru einföldustu lífrænu efnin • Kolvetni eru gerð úr Kolefni og Vetni • Kolvetni þar sem öll tengi milli atóma eru einföld kallast ALKANar • Öll eintengi eru sigmatengi (σ-bonds) og um þau frjás snúningur. • Einföldustu: CH4, C2H6, C3H8

17. Um kolvetni • Mettað kolvetni (Saturated hydrocarbon):Kolvetni eingöngu með eintengi • Alkane: Mettuð kolvetni þar sem kolefnin raða sér í opna keðju. • Aliphatic hydrocarbon:Annað nafn á alkan

18. Hydrocarbons

19. Bygging • Lögun • Ferflötungslaga • Öll horn tengja um 109.5°

20. Drawing Alkanes • Nokkrar aðferðir við að teikna byggingu • Endi og horn eru kolefnisatóm (line-angle)

21. IUPAC • International Unionof Pureand Applied Chemistry • Látum nægja að læra utanað upp í 10 en allt ofar þarf að kannast við. • Sjá annars töflu 11.1 í bók.

22. Línulaga - Beinkeðjualkanar Nafn # Kolefni Byggingaformúla Methane 1 CH4 Ethane 2 CH3CH3 Propane 3 CH3CH2CH3 Butane 4 CH3CH2CH2CH3 Pentane 5 CH3CH2CH2CH2CH3

23. IUPAC NAMES Nafn # C-atóma Byggingaformúla Hexane 6 CH3CH2CH2CH2CH2CH3 Heptane 7 CH3CH2CH2CH2CH2CH2CH3 Octane 8 CH3CH2CH2CH2CH2CH2CH2CH3 Nonane 9 CH3 CH2 CH2CH2CH2CH2CH2CH2CH3 Decane 10 CH3CH2CH2CH2CH2CH2CH2CH2CH2CH3

24. Dæmi A. Hver er byggingaformúla… H H H H H C C C C H H H H H B. Hver er mólikúlformúlan? C. Hvert er nafnið?

25. Lausn A. CH3CH2CH2CH3 B. C4H10 C. butane

26. Nafnakerfi - IUPAC • Forskeyti/Prefix segir fjölda C-atóma

27. Nöfn: Greinóttra alkana • Finndu lengstu kolefniskeðjuna. • Númera keðjuna, byrja þaðan sem styst er í fyrstu hliðargrein. • Nefnið hliðarhópa og notið númer á C sem staðsetningu. • Raðið hliðarhópum (substituents) í stafrófsröð. • Notið di-, tri-, ef sami hópur kemur oft fyrir. =>

28. => Lengsta keðjan • Fjöldi kolefnisatóma í lengstu keðju ræður orðstofni/Nafni • Ef það eru tvær keðjur jafnlangar velst sú keðja sem hefur fleiri hliðarhópa.

29. 1 3 4 5 2 6 7 Númera C -atóm • Byrjið við endann næst fyrsta hliðarhóp. • Ef tveir hl.hópar eru jafn langt frá skoðið þá aðra hópa. =>

30. => Nöfn hliðarhópa – ALKYL hópar • CH3-, methyl • CH3CH2-, ethyl • CH3CH2CH2-, n-propyl • CH3CH2CH2CH2-, n-butyl

31. Alphabetize • Raðið í stafrófsröð. • Ignore di-, tri-, í stafrófsröðinni. 3-ethyl-2,6-dimethylheptane =>

32. 1 2 3 Flóknari hliðarhópar • Ef greinin er greinótt, númerið C in frá tengi við aðalkeðju. • Nefnið og númerið hliðarkeðju í hliðarkeðju. • Setjið sviga utanum flókna hliðarhópinn. 1-methyl-3-(1,2-dimethylpropyl)cyclohexane =>

33. Nomenclature - IUPAC • Parent name: the longest carbon chain • Substituent: a group bonded to the parent chain • alkyl group: a substituent derived by removal of a hydrogen from an alkane; given the symbol R-

34. Nomenclature - IUPAC 1.The name of a saturated hydrocarbon with an unbranched chain consists of a prefix and suffix 2. The parent chain is the longest chain of carbon atoms 3. Each substituent is given a name and a number 4. If there is one substituent, number the chain from the end that gives it the lower number

35. Nomenclature - IUPAC 5. If there are two or more identical substituents, number the chain from the end that gives the lower number to the substituent encountered first • indicate the number of times the substituent appears by a prefix di-, tri-, tetra-, etc. • use commas to separate position numbers

36. Nomenclature - IUPAC 6. If there are two or more different substituents, • list them in alphabetical order • number from the end of the chain that gives the substituent encountered first the lower number

37. Nomenclature - IUPAC 7. The prefixes di-, tri-, tetra-, etc. are not included in alphabetization • alphabetize the names of substituents first and then insert these prefixes

38. Nomenclature - IUPAC • Alkyl groups

39. Nomenclature - Common • The number of carbons in the alkane determines the name • all alkanes with four carbons are butanes, those with five carbons are pentanes, etc. • iso- indicates the chain terminates in -CH(CH3)2; neo- that it terminates in -C(CH3)3

40. Propyl Groups H H n-propyl isopropyl A secondary carbon => A primary carbon

41. Butyl Groups H H n-butyl sec-butyl A secondary carbon => A primary carbon

42. Isobutyl Groups H H isobutyl tert-butyl A tertiary carbon => A primary carbon

43. Alkyl Groups Branches on carbon chains H H C CH3 methyl H H H H C C CH3CH2 ethyl H H

44. Branched Alkanes CH3 CH3CHCH3 methyl groups CH3 CH3 CH3CHCH2CHCH3

45. Naming Branched Alkanes CH3 methyl branch CH3CH2CH2CHCH2CH3 6 5 4 3 2 1 Count

46. Naming Branched Alkanes CH3 methyl branch CH3CH2CH2CHCH2CH3 6 5 4 3 2 1 Count 3-Methylhexane on third C CH3 six carbon chain group

47. Naming Summary 1. Count the C’s in the longest chain 2. Name each attached group 3 Count the longest carbon chain to give the first attached group the smallest number 4. Name and locate each group

48. Dæmi A. CH3CH3 CH3CHCH2CHCH3 B. CH3 CH3 CH3CH2CHCH2CCH2CH3 CH3

49. Svör A. CH3CH3 CH3CHCH2CHCH3 2,4-dimethylpentane B. CH3 CH3 CH3CH2CHCH2CCH2CH3 CH3 3,3,5-trimethylheptane

50. Dæmi Write a condensed structure for A. 3,4-dimethylheptane B. 2,2-dimethyloctane