INTRODUTION TO ORGANI EMISTRY GENERAL DESRIPTION OF ORGANI EMISTRY The Study of arbon ompounds
GENERAL DESRIPTION OF ORGANI EMISTRY The Study of arbon ompounds Organic Man-made Substances Plant or Animal Origins morphine, penicillin Fibers: cotton, silk, wool Fats, arbohydrates, Proteins, Vitamins Natural rubber, Natural gas, petroleum Xyloaine, Aspirin, Acetaminophen Nylon, Dacron, Rayon Saran, Teflon Man-Made Rubber, Synfuels
Differences Between Organic and Inorganic ompounds Inorganic Organic Elements Present Metals and Nometals Mostly arbon Bonding ovalent and Ionic Mostly ovalent Particles IONS & molecules ions & MOLEULES Melting Points Relatively igh Relatively Low Boiling Points Relatively igh Relatively Low Electrolytes STRONG to weak weak to NON
omparison of Physical Properties of Organic and Inorganic ompounds Name Salt Ethyl alcohol Benzene Formula Nal 26O 66 Organic/Inorganic Inorganic Organic Organic Melting Point 804 º -117 º 5 º Boiling Point 1413 º 78 º 80 º Burns in O2? No Yes Yes Water Soluble? Yes Yes No
WY ARBON? Intermediate Electronegativity - Favors ovalent Bonds Ability to Form hains - (atenation) Ability to Form Multiple Bonds and Rings
Allotropes of arbon
ydrocarbons (contain and ) The Simplest lass of Organic ompounds arbon can bond in different ways 4
Because carbon and hydrogen are so common, abbreviations are used. 3 2 2 2 ( 2 ) 2
Structural Formulas and ondensed Structures Example of a ondensed Structure: What does the molecular formula 1122O represent? O 3 3 3 ( 2 ) 4 O
Remember that structural formulas do not always reflect true 3-D structures
ydrocarbons The Simplest lass of Organic ompounds arbon can bond in different ways (multiple bonds) 24 22
Structural Formulas and Bond Angles Methane (109.5º angles) 120º 180º
Structural Representation of Simple Alkanes
Formulas and Properties of Normal Alkanes n Molecular ondensed Name Melting Boiling Formula Structural Formula point ( o ) point ( o ) 1 4 4 methane -182-162 2 26 33 ethane -183-89 3 38 323 propane -190-42 4 410 3223 butane -138-1 5 512 32223 pentane -130 36 6 614 322223 hexane -95 69 7 716 3222223 heptane -91 98 8 818 32222223 octane -57 126 9 920 322222223 nonane -51 151 10 1022 3222222223 decane -30 174
Kinds of Attractive Forces Dispersion Forces Temporary polarity in molecules due to unequal electron distribution Dipole Dipole Attractions Permanent polarity in molecules due to their structure ydrogen Bonds An especially strong dipole dipole attraction resulting from the attachment of to an extremely electronegative atom
Properties of Straight hain Alkanes NonPolar Molecules
Molecular shape and boiling point. more points for dispersion forces to act fewer points for dispersion forces to act
1. hoose the Substance in Each Pair with the igher Boiling Point a) 4 410 b) 612 612
Physical Properties of Alkanes The Basis for Fractional Distillation
Uses of ydrocarbons
Isomerism A. A molecular formula may not convey a unique structure. B. Isomers - ompounds with identical molecular formulas, but different structural formulas.. Example #1: 410 ompound 3 2 2 3 3 3 3 Name Butane Isobutane Melting point -138 o -160 o Boiling point 0 o -12 o Density 0.601 g/ml 0.557 g/ml
Isomerism n-butane butane iso-butane 2-methylpropane
Isomerism Another example and 714 714
NOMENLATURE OF YDROARBONS Why is the IUPA system Necessary? onsider the following carbon hydrides 4 26 24 22 Each formula represents a unique compound If structural formulas (arrangement in space) are considered, 37 has only 1 isomer. 410 has 2 isomers. 512 has 3 isomers. 614 has 5 isomers. 1022 has 75 isomers. 3062 has 4 x 10 9 isomers.
Basis of the IUPA System of Naming 1. The root name of a compound is derived from the longest continuous chain of carbon atoms or the longest continuous chain of carbon atoms containing a given special structural feature.
2. ommon stems used to indicate the length of carbon chains. 3. ommon suffixes used to indicate the class of compounds. Alkane Alkene Alkyne
n Molecular ondensed Name Melting Boiling Formula Structural Formula point ( o ) point ( o ) 1 4 methane 4-182 -162 2 26 ethane -183-89 33 3 38 propane -190-42 323 4 410 3223 butane -138-1 5 512 pentane -130 36 32223 6 614 322223 hexane -95 69 7 716 heptane -91 98 3222223 8 818 32222223 octane -57 126 9 920 322222223 nonane -51 151 10 1022 3222222223 decane -30 174
Alkenes
Alkynes
4. If the carbon chain contains unsaturation (double or triple bonds), the carbon chain is numbered so as to give double or triple bonds the lowest number. 1 2 3 4 1 2 3 4 1 2 3 4 1-Butene 2-Butene 3-Butene 4 3 2 1 1-Butene
Substituents may be attached to a carbon chain 1. Substituents which are not pieces of alkanes: F- Fluoro- -NO2 Nitro l- hloro- -N2 Amino Br- Bromo- -O ydroxy I- Iodo- 2. Akyl Substituents - names derived from alkane names 3-, methyl 32-, ethyl 322-, propyl -yl =substituent
2. 1226 5-ethyl-4-methylnonane
nonane dimethyl 4,5-4,4- dimethyl nonane 1124 1124 4. 3.
ydrocarbon Nomenclature Putting it Together for a Simple Alkane 5. 3 3 3 3 3 2 2 3 3 2 2 7 6 5 4 3 3 2 2 2 3 1 3 Position of alkyl groups Family 4-isopropyl-3-methyl heptane Base name Alkyl groups Longest chain
Nomenclature of Alkenes 6. 2 3 2 2 2 2 2 2 3 2 2 3 3 2-ethyl -4,5- dipropyl-1-octene
ydrocarbon Nomenclature A more complicated example 7. 3 3 3 2 l 2 2 2 2 3 2 l 2 l 3 3 3 2 l 2 2 2 2 3 2 l 2 l 3 3 3 3 2 3 2 2 2 2 3 l 3 l 2 2 l 1,3,5-trichloro-5-isobutyl-3,9-dimethyl decane
hemical Reactions of ydrocarbons ombustion Reactions
ombustion - Burning in Oxygen 8. Propane burns in oxygen to yield carbon dioxide and water. 38 + O2 ---------------> O2 + 2O 38 +? O2 ---------------> 3 O2 + 4 2O 38 + 5 O2 ---------------> 3 O2 + 4 2O
9. ombustion - Burning in Oxygen Butane burns in oxygen to yield carbon dioxide and water. 410 + O2 ---------------> O2 + 2O 410 +? O2 ---------------> 4 O2 + 5 2O 2 410 +? O2 ---------------> 8 O2 + 10 2O 2 410 + 13 O2 ---------------> 8 O2 + 10 2O
Families of Organic ompounds Alkanes O Aldehydes O Alkenes Ketones Alkynes O O arboxylic Acids Aromatics O O Esters O Alcohols N Amines O O Ethers N Amides
Families of Organic ompounds Family General Formula Example Name hydrocarbons 3 2 3 propane alcohols R-O 3 2 2 O 1-propanol 3 3 O 2-propanol ethers R-O-R 3 O 3 dimethyl ether 3 O 2 3 ethyl methyl ether aldehydes R-O O 3 2 propanal ketones R-(O)-R 2-pentanone 3 O 2 2 3 O 3 2 2 3 3-pentanone
Families of Organic ompounds Family General Formula Example Name carboxylic acids R-OO propanoic acid O 3 2 O esters R-OOR methyl propanoate O 3 2 O 3 O ethyl ethanoate 3 O 2 3 amines R-N2 3 2 2 N 2 propyl amine amides R-(O)-N2 propanamide O 3 2 N 2 3 2 O N 3 N-methyl propanamide
3 O 3 2 O 2 methyl ether ethylene oxide 3 2 3 O propane 3 3 N acetaldehyde acetonitrile
methyl ether b.p., 249 K ethylene oxide b.p., 284 K propane b.p., 231 K acetaldehyde b.p., 293 K acetonitrile b.p., 355 K
Families of Organic ompounds
10. hoose the substance in each pair with the higher boiling point a) 2F2F or 3F2 no net dipole net dipole
10. hoose the substance in each pair with the higher boiling point b) or net dipole no net dipole
Effect of -Bonding on Boiling Point 11. hoose the substance in each pair that is a liquid at room temperature (the other is a gas) a) 3O 3F2 b) 3-O-23 322N2