Organic Chemistry!!! Chapters 22, 23 and 24

Organic Chemistry The study of carbon and carbon compounds MUCH more abundant than inorganic compounds

BONDING Organic Compounds bond covalently Share electrons Form molecules

MORE BONDING Carbon atoms bond to one another in: Chains: C-C-C-C-C-C Rings: Networks:

Even More Bonding Carbon atoms have 4 valence electrons EN=2.6 (forms mostly covalent bonds) Shares 4 electrons with other atoms to attain octet

Types of Covalent Bonds Carbon atoms may form: Single bonds Double bonds Triple bonds

Structural Formulas Represents the arrangement of atoms in a compound Indicates bonding pattern and shapes CH 4 CH 3 OH CH 3 CH 2 CH 2 OH Tetrahedral shape-CH 4 : 4 bonds spread out to the 4 corners

ISOMERS Compounds with same molecular formula, but different structural formulas Same # and type of atoms, different arrangement (bonding patterns different)

ISOMERS C 3 H 6 O (molecular formula) CH 3 COCH 3 CH 3 CH 2 CHO (structural formulas)

HYDROCARBONS Compounds that contain only C and H atoms Saturated: contain only single bonds Unsaturated: contain at least 1 multiple bond (double or triple)

Homologous Series of Hydrocarbons TABLE Q Group of organic compounds with similar properties and related structures

Homologous Series The formulas of members of a h. s. differ from each other by some common increment As molecular size increases, increase weak imf, increase b.p., increase f.p. (harder to melt)

ALKANES Single bonds only (saturated) Table Q: C n H 2n+2 Prefix: # of carbons in longest chain (Table P) Ending: -ane Isomers show up starting with C 4 H 10 butane

ALKENES One double bond between carbons (unsaturated) Table Q: C n H 2n Prefix: Table P (# of C in longest chain) Ending: -ene Position of the double bond may vary (isomers)

Alkenes Longest chain is numbered, starting at end closest to double bond The lower # of C with double bond precedes the name of the hydrocarbon

ALKYNES One triple bond between carbons (unsaturated) Table Q: C n H 2n-2 Prefix: Table P (# C in longest C chain) Ending: -yne Position of the triple bond may vary (isomers)

Alkynes Longest chain is numbered, starting at end closest to triple bond Lower # of the C with triple bond precedes the name of the hydrocarbon

Other Organic Compounds- Table R Replace 1 or more hydrogen atoms with other element or group Replacement is called a functional group

HALIDES (Group 17) R-X Replace H in a hydrocarbon with halogen Halogen name is shortened to end in -o There can be more than 1 halogen added to a hydrocarbon (replace more than 1 H) Prefixes to indicate number

ALCOHOLS Functional group: -OH (R-OH) -OH is alcohol in organic, base in inorganic Alcohol: does not form hydroxide ion in solution; not an ionic compound but a molecule

Naming Alcohols Number of C attached to it (if 3 or more C) Name hydrocarbon first Replace final -e with -ol Classes of alcohols: Monohydroxy: one -OH group Dihydroxy: two -OH groups Trihydroxy: three -OH groups

1-propanol

Ethers Functional Group: -O- ; R 1 -O-R 2 Diethyl ether (solvent and anesthetic) C 2 H 5 OC 2 H 5 Methyl ethyl ether CH 3 OCH 2 CH 3

diethylether

Methyl ethyl ether

ALdehydes Functional group: -C=O Naming: replace the -e of hydrocarbon with -al Only one available bonding site, usually found at end of chain H

Methanal (formaldehyde)

ketones Naming: replace the ending -e with -one Simplest ketone is when R 1 and R 2 are methyl groups (-CH 3 ) Ketones are isomers of aldehydes (ketones have 2 R groups, aldehydes 1 R)

ketONEs

Propanone (acetone)

OrganIC ACID Functional Group: -COOH

To name organic acids Replace ending -e with -oic acid Methanoic acid:

Ester COOC- R ’ is named first (group attached to the -O-), -e is replaced with -yl R is named next (group attached to -C) -e is replaced by -oate

Methyl ethanoate

Amine Naming: drop the -e and replace with -amine

Amides Combines a carbonyl (double bonded oxygen) and an amine on the same C.

Amides Naming: replace -e with -amide

General Characteristics of Organic Compounds molecular compounds (contrast with ionic compounds) NONPOLAR (mostly) Few dissolve in water (polar) Vinegar (acetic acid) Various sugars and alcohols (all have -OH like water)

More characteristics Nonelectrolytes Not ionic COOH (organic acids) are weak electrolytes Low melting points (weak IMFs) Slow reaction rates High E a needed Catalysts used Covalent bonds are strong (harder to break)

Organic Reactions Organic reactions occur at much slower rates than inorganic reactions In an organic reaction, the functional groups are usually involved TABLE R!!!

Combustion Saturated hydrocarbon + O 2  CO 2 + H 2 O + heat Energy derived by combustion and cellular respiration Oxidation reactions (oxygen involved)

Substitution Occurs in saturated hydrocarbons (alkanes) Replace a hydrogen with another element or group More than 1 product is typical

Substitution Ethane + bromine  bromoethane + hydrogen bromide C 2 H 6 + Br 2  C 2 H 5 Br + HBr

Addition Adding two or more atoms to C-atoms in unsaturated hydrocarbons Usually saturates the bond  makes a single bond Takes place more easily than substitution reactions Unsaturated compounds more reactive than saturated compounds

Addition continued Triple bonds (alkynes) more reactive than double bonds (alkenes) Reactivity: alkynes > alkenes > alkanes Addition of H= hydrogenation Requires a catalyst and elevated temperature “partially hydrogenated oils” Characterized by the formation of a single product

Fermentation Molecules broken down Alcohol production (CO 2 made also- carbonation) Usually associated with living organisms Yeast Enzymes serve as catalysts

Fermentation Example Fermentation of Glucose Zymase- made by yeast

Esterification Organic acid + alcohol  ester + water Esters have a first and last name (R’ and R) R’= first name: alcohol name with -yl ending R= last name: organic acid name with -oate ending Example: ethanoic acid + methanol --> methyl ethanoate + water

Esters Are responsible for aromas Fruits, flowers, leaves Lipids (fats and oils) are esters Made from glycerol and fatty acids Compared to inorganic process of neutralization (Acid + Base  salt + water)

Saponification Making soap Animal fat + base  soap + glycerol Hydrolysis of fats (complex esters) by bases Break apart esters Reverse of esterification Break esters into acid and alcohol

Polymerization Make a long chain (polymer) by bonding smaller chains (monomers) Plastics, nylon, rayon, proteins, starches, cellulose Two types of polymerization: Condensation Addition

Condensation Bond monomers by dehydration (removing water) Monomer + monomer  polymer + H 2 O

Addition Join monomers of unsaturated compounds by “opening” a multiple bond of the carbon chain