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Organic Chemistry. A. Carbon Compounds. organic compounds are those in which carbon atoms are almost always bonded to each other, to hydrogen atoms and a few other atoms. (O, N, S, P). inorganic exceptions are the. oxides of carbon,. carbonates,. cyanides. and carbides.
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Organic Chemistry A. Carbon Compounds • organic compounds are those in which carbonatoms are almost always bonded to each other, to hydrogenatoms and a few other atoms (O, N, S, P) • inorganic exceptions are the oxides of carbon, carbonates, cyanides and carbides (no C-C bonds or C-H bonds) eg) CO2, CaCO3, NaCN, SiC • there are millions of organic compounds and all contain covalent bonds
carbon is unique for two reasons: a) it can bond with atoms to form long chains, rings, spheres, tubes, sheets etc. other carbon b) it can form combinations of single, double and triple bonds (no other element does this!!!!)
recall polarity and intermolecular forces from the chemical bonding unit • polar bonds are formed when there is an unevenpull on e • polar compounds are formed when the polar bonds within a molecule do not canceleach other out • the presence of dipole-dipoleforces and hydrogen bonding will allow polar compounds to dissolve in water, since it is also polar • non-polar compounds only have LD forces between molecules and will notdissolve in water
B. Structural Isomers • isomers are compounds with the same molecular formula but a different structure
H H H H H H C C C C C H H H H H H H H H H H C C C C H H CH3 H H CH3 H H H C C C H H C H3 H Example 1 Draw the three structural isomers for C5H12. 1. 2. 3.
H H H H H H H H H F F F H H H C C C C C C C C C C C C H H H H H H H H F H H F H F H Example 2 Draw three structural isomers for C4H8F2 . 1. 2. 3.
different structures result in different properties • the arrangement of the atoms determines the types of intermolecular attractions which then determines properties such as and in water boiling point solubility
H H H H C C C H H OH H H H H H C O C C H H H H Example Draw two isomers of C3H8O. Which one would have a boiling point of 7.4C and which would have a boiling point of 82.5C? Explain why the boiling points are so different. has HB between molecules which makes the boiling point quite high 82.5C – does not have HB between molecules therefore the boiling point is significantly lower 7.4C –
H H H H H H H H C C C C C C F H H H H H H H C. Formulas and Structural Diagrams • organic molecules can be drawn in three different ways: 1. complete structural diagram – shows all bonds eg) C3H8 eg) C3H7F
CH3 CH3 CH2 CH2 CH3 CH2F 2. condensed structural diagrams – shows but includes the etc. attached to each carbon carbon to carbon bonds hydrogens eg) C3H8 eg) C3H7F
3. line structural diagrams – shows only bonds carbon to carbon eg) C3H8 eg) C5H12 eg) C4H8
D. Prefixes 1. Number of Functional Groups hexa 6 = 2 = 7 = 3 = 8 = 4 = 9 = 5 = 10 = di hepta tri octa tetra nona deca penta
2. Number of Carbons meth hex 1 = 6 = 2 = 7 = 3 = 8 = 4 = 9 = 5 = 10 = hept eth prop oct but non pent dec
E. Alkanes CnH2n+2 eg) C5H12, C20H42, etc. • hydrocarbons containing only single bonds ie) they are SATURATED long branched • can be continuous chains, chains, structures ring (cycloalkanes)
1. Properties nonpolar not soluble in water • can be depending on number of carbon atoms solid, liquid or gas • relatively because the bonds are unreactive single very stable
2. Uses natural gas, BBQ’s, lighter fluid, gasoline etc good for making plastics, lubricants 3. Naming International Union of Pure and Applied Chemistry • IUPAC =
H H H H H C C C C H H H H H i. Continuous Chains prefix + “ANE” (suffix) eg) butane
ii. Branched Chains • branches are called functional group alkyl • 1 C = ; 2C = ; 3 C = etc methyl ethyl propyl • find the and so the branches get the longest carbon chain number it lowest possible numbers groups alphabetical • to name: name thefirst(inorder),including thewhere each group is found, then name the number of the carbon longest chain (parent name)
H H H H H H H C H C H C H H C C H H CH3 CH2 H H H C C C C C H CH3 H H CH3 H H eg) 3-methylpentane 1 2 3 4 5 methyl 1 2 3 4 5 3-ethyl-2-methylpentane methyl ethyl
H H H H H H C C C C C H H H CH3 CH3 H eg) 5 4 3 2 1 methyl methyl 2,3-dimethylpentane
iii. Cycloalkanes • use the as the name ring structure “parent” • + + “cyclo” prefix ANE eg) cyclobutane cyclopropane
CH2 CH3 CH3 • if there are branches, number the carbons in the ring so the branches get the lowest possible number sequence eg) 5 4 1 ethyl 3 2 methyl 1-ethyl-3-methylcyclopentane
F. Alkenes CnH2n eg) C5H10, C20H40, etc. • hydrocarbons containing one or more double bonds ie) they are UNSATURATED • can be continuous chains, chains, structures long branched ring (cycloalkenes)
1. Properties nonpolar not soluble in water • than corresponding alkane because they have which makes the forces of attraction lower boiling point fewer e LD weaker eg) ethane BP = 88.6C ethene BP = 103.8C • than alkanes more reactive • double bond has in the same area and more e- greater repulsion bond less stable
Br2(l) A B KMnO4(l) A B • diagnostic test: use KMnO4(aq) or Br2(l) ***alkenes with these substances causing a noticeable alkanes will not (double bond) will react colour change, alkene alkane alkane alkene ***the alkenes will react causing the colour to disappear as the coloured substance is used up in the reaction
2. Uses plastics (PVC) steroids welding torches 3. Naming i. Continuous Chains prefix + “ENE”(suffix) • number carbons to give the the double bond lowest number • the number where the double bond is to be given as a “ # ” between the prefix and the suffix starts
H H H H H ‗ H H H H H H C C C C C H ‗ H C C C C C H C H H H H H H H H H H H H ‗ C C C C H H H H eg) hex-3-ene pent-2-ene but-1-ene
ii. Branched Chains • find the longest carbon chain and number it so the gets the double bond lowest possible number groups • to name: name thefirst(inorder), including theof the carbon where each is found, thentheincluding the of the carbon where the double bond starts alphabetical number parent name number
‗ CH2 C CH2 CH2 CH2 CH2 CH3 CH2 CH3 ‗ CH3 CH CH CH CH CH CH3 CH3 CH3 CH2 CH2 CH3 eg) 2-ethylhept-1-ene 4,5,6-trimethylnon-2-ene
iii. Cycloalkenes • double bond is always numbered 1, 2 • get the after the branches lowest numbering sequence double bond • + + “cyclo” prefix ENE • list branches in with the alphabetical order number of the carbon they are on
CH3 CH2 CH3 CH3 CH2 CH3 cyclohexene eg) cyclopropene 2 3 3-ethylcyclobutene 1 4 4 1 2 3 3-ethyl-1,3-dimethylcyclobutene
G. Alkynes CnH2n-2 eg) C5H8, C20H38, etc. • hydrocarbons containing one or more triple bonds ie)they arealso UNSATURATED • can be continuous chains,chains long branched • not plentiful in nature
1. Properties nonpolar very reactive (more than alkanes and alkenes) triple 6 e- • bond hasin the same area force of repulsion high • boiling points are than corresponding alkanes and alkenes because of their and the of triple bonds higher linear structure nature 2. Uses welding torches
3. Naming i. Continuous Chains prefix + “YNE” • number carbons to give the the triple bond lowest number • the number where the triple bond is to be given as a “ # ” between the prefix and the suffix starts
H H H H H C C C C C C H ≡ H H H H H H H H C C C C C H ≡ H H H eg) hex-3-yne pent-2-yne
ii. Branched Chains • find the and number it so the gets the lowest number longest carbon chain triple bond • to name: groups alphabetical name thefirst(inorder), including theof the carbon where each is found, thentheincluding the of the carbon where the triple bond starts number parent name number
≡ CH C CH CH2 CH2 CH2 CH2 CH3 CH2 CH2 CH3 CH3 CH C C CH CH CH3 ≡ CH3 CH2 CH3 CH3 eg) 3-propyloct-1-yne 2,5,6-trimethyloct-3-yne
Review alkanes – branches, rings – least reactive alkenes – branches, rings alkynes – branches – most reactive aliphatics all called • allandin water nonpolar not soluble LD major intermolecular forces are boiling points are low
H. Aromatics • hydrocarbons containing one or more benzene rings C6H6 OR • all bonds are the same length and strength we draw benzene like this:
1. Properties nonpolar • the benzene ring structure is very stable • aromatics are characterized by strong aromas
2. Uses ASA, amphetamines, adrenaline, benzocaine (anesthetic) moth balls, TNT wintergreen, menthol, vanilla, cinnamon SPF in sunscreen
CH3 CH2 ‗ CH2 CH2 CH CH CH2 C CH2 CH3 CH2 CH CH2 CH2 CH3 CH3 3. Naming i. Benzene as a Branch • if you have a really long carbon chain, it is easier to call the benzene ring a “phenyl” group eg) 4-phenylheptane 3-methyl-5,5-diphenyloct-1-ene
CH3 ii. Benzene as a the Main Compound • if only one group is attached, give the attached to alkyl name “benzene” (no number is necessary) eg) methylbenzene
CH3 CH2 CH3 CH3 CH3 CH3 CH2 CH2 • if there is more than one branch, number them so they get the and name lowest sequence alphabetically eg) 1-ethyl-3-methylbenzene 1,3-dimethyl-5-propylbenzene
C2H5 CH3 1-ethyl-3-methylcyclohexane ***Watch out for this!!!
R - OH I. Alcohols • organic compounds with one or more OH (hydroxyl) groups 1. Properties have much than corresponding aliphatics because of higher boiling points hydrogen bonding! eg) methane (CH4) BP = methanol (CH3OH) BP = -162C 65C
polar the end of the alcohol is while the end small alcohols are in water and large alcohols are –OH polar carbon chain is not soluble not 2. Uses antifreeze, rubbing alcohol, beverages, moistening agent
3. Naming • number the longest carbon chaincontaining the so the group gets the hydroxyl group –OH lowest number • name at end aliphatic (without “e” ) + “OL” • give the where the is found between the parent name and the suffix number for the carbon –OH group
if there is hydroxyl group, use a prefix ( ) to indicate the of OH groups and place the numbers between the parent name and the suffix more than one di, tri, tetra number ***Note, if the suffix starts with a vowel, drop the “e” on the parent name; if the suffix starts with a consonant, keep the “e” on the parent name
H H H H H C C C C H H CH3 H H H H OH H H C C C C H H H OH H eg) butan-2-ol 3-methylbutan-2-ol